Ecotrons Engine Management

[speedpro]

A few of us have these systems now. I thought it might be useful to have a separate thread to swap information. I'm just starting with mine on a 4 stroke twin that will eventually be turbo or supercharged, Rob has his 2 stroke single with triple injectors coming along, and Sketchy with his supercharged Honda clone.

I'm using a kit designed for a Kawasaki 250 Ninja. I already see a few possible problems with the triggering even though the FZR has 4 teeth on the flywheel the same as the Ninja, I'm not sure where the long tooth lies in relation to which cylinder is firing and then how many degrees after that the next one fires. On a 180degree twin the firing intervals are odd - 180deg and 540 deg. I'm sure it's configurable but I haven't got there yet.

[Sketchy_Racer]

Yep, mine has been great for testing the supercharger bike, they do have their quirks though.

When setting it up, make sure you have excellent grounding for the system, without it the noise from the ignition coil etc can make all sorts of odd things happen.

If you experience a odd running condition, it is most likely that the Map file was corrupted when transferring from the PC to the ecu, just re-burn the map and it should solve it.

The fuel factor ratio adjustment is far more sensitive than it would seem, a movement of 0.1 is probably close to 10 jet sizes. Also remember that this affects fuel mixture throughout the entire RPM/TPS range. It is great for getting the bike running but after tuning ideally should be set back to 1.

USB extension leads on the cable suck, use a long RS232 cable.

The extra fuel pump and wires a real pain the in arse, I am going for an internal fuel pump soon, using a fuel injected scooter pump/regulator to keep current draw down.

I can't wait to get back into making the batch of superchargers, still working on supply for some parts then it will be all on!

Cheers,

-Sketchy

[speedpro]

I haven't seen the fuel pump being a problem. I'd be interested in a bit more detail about the problems and also what option you are going to use. I've thought that the FI scooters must have some good stuff and the right size as well. The OEM bits will be a bit pricey though I'd think.

[Flettner]

I'm interested to see how things pan out too.

[TZ350]

284191

EFI Lambda Chart ......

[speedpro]

The system is pretty well installed now. I have a battery connected just for testing and hope to turn it using a dyno to check for sparks and where they occur. Unfortunately I still don't have the correct alternator rotor for this crankshaft so can't fire it up yet. However the rotor I have for the smaller crank does fit on the end of the crank taper so good enough to test the triggering. One little problem I seem to have is that when I switch power on with no ground connection from the battery -ve, the fuel pump runs for a short period of time as it should. With the battery -ve connected directly to ground the fuel pump gets erratic starting if it will start at all. Possible wiring problem of course. I should go over my crimp connections with the soldering iron.

I have a few options like simply swapping the coil connections from #1 to #2 or swapping which intake runner the MAP sensor is connected to if the sparks aren't close to where they should be. If that doesn't work I'm going to need to have a really good read of the tuning manual.

I'm starting to see a drawback to this system in that it is difficult to decipher the parameters and the effects they have. It's sort of like a DOS system in a Windows world. It'll do it but finding out how isn't going to be easy.

[Sketchy_Racer]

I'm starting to see a drawback to this system in that it is difficult to decipher the parameters and the effects they have. It's sort of like a DOS system in a Windows world. It'll do it but finding out how isn't going to be easy.

You'll get used to it, i thought it was shit to begin with but ive gotten used to it now.

[speedpro]

I've spent a couple of days looking at the problem. I had the ECU bolted to an alloy bracket I made which was bolted to the chassis. With no ground wire from the battery -ve to chassis ground the fuel pump ran for 5 seconds at power on as it should but I measured 6vDC on the -ve terminal compared to the chassis, so obviously it needed to be connected to ground. This seemed to be required to provide a return circuit for the power supplied to the coils as well. The problem was when I connected it the fuel pump would not start. There was about 9mA flowing from battery -ve to chassis ground with power on. When spinning the engine by hand the fuel pump would run for 1-2seconds so obviously the crank pickup was being detected.

What I've ended up doing is isolating the ECU case from chassis ground and connecting battery -ve to chassis ground as per the manual. So the ECU case now floats at about 6vDC. Now the fuel pump fires up at power on for 5 seconds, as before, plus it still runs for a short time each time the engine is turned, plus I have the battery -ve connected to chassis ground so hopefully the ignition will work as well. I couldn't see sparks as I turned the back wheel but I'm sure I could hear them.

Lesson - the ECU case needs to be isolated from chassis ground.

Time to hook a PC to it and turn it on the dyno to see what's going on.

[speedpro]

I've put the bike on JC's dyno to turn the engine. Had a PC connected and monitored and recorded what was going on. The dyno starter motor doesn't have the grunt to continually spin the engine so it was just short bursts after the roller got turning with a bit of speed.

Still got no spark even though the ECU indicates that it should. I suspect a wiring problem. I'm sure I read that the -ve side of the coils goes to ground and the ECU supplies +12v to the other side. I forgot my multimeter so couldn't check for any voltage on the coils. Apart from that it looks like it'll run. The MAP sensor cycles and everything else bounces up and down. Interesting that the injectors look to fire simultaneously as both injector waveforms are identical and in sync.

If I can't get a rotor reasonably soon I'll make a rotor disc and bolt it to the inner hub I have that fits this crankshaft and just fire it up using total loss. It'll be OK on the dyno as I can hook up the battery charger.

So, the call goes out again, if you have a Yamaha FZR loafing round I'm interested in the rotor.
037000-2110 11FZ LKZ01 & 037000-2660 2KX LKZ12 are not the correct ones. If anyone has a FZR250 alternator rotor with different numbers on it I'd like to have a chat.

[speedpro]

Woohoo, big fat sparks. Just turning it over by hand but the sparks look to be a bit erratic as to timing. It might need to turn a couple more times to get it's act together. Back to the dyno.

[Drew]

Woohoo, big fat sparks. Just turning it over by hand but the sparks look to be a bit erratic as to timing. It might need to turn a couple more times to get it's act together. Back to the dyno.Was the problem that you had the coils fed from the ECU, rather than grounding through it?

[speedpro]

I needed to have one side of each coil supplied with +12V which is normal. I had it with one side of each coil grounded which was the only configuration I could find in the manuals, but of course they were CDI systems. I thought it was odd, certainly not normal but electrically no reason why not. Speaking to JC tonight and he was silly enough to let on that he has a little mill that he uses to make trigger discs so unless the correct rotor turns up on the doorstep I'll be making a disc this weekend and bolting it to the correct hub I have my cam timing degree wheel bolted to. I just need to confirm the timing of the trigger teeth on the Kawasaki Ninja which my Ecotrons system is built for.

[speedpro]

Throttle cable?? It turns out that a Yamaha 125 scooter cable bolts to the Ecotrons throttle body like it was built for it. It also fits into a MB100 twist grip like it was built for it, and the length of the inner is perfect. The only downside is that being a scooter throttle cable it's about 2' too long so I've run a loop. Being Teflon lined it's still super smooth. Don't you love it when stuff you have lying round just drops in.

[Drew]

Don't you love it when stuff you have lying round just drops in.It's always AWESOME when ya don't have to make stuff to fit!

[speedpro]

Has anybody looked at defining the trigger teeth arrangement in software? It looks like you need to have access to advanced features as the variables aren't listed.

[TZ350]

285713285714285715285712

Advanced - Add Advanced Calibrations - Drop Down Menu - Read the descriptions at the bottom of the screen.

Speedpro is this the one your looking for?

[speedpro]

one of them.

[speedpro]

Strapped the bike on JC's dyno. Turned it over and checked the timing for cylinder #1 - looks good. checked timing for cylinder 2 - looks good!!! Tipped some fuel in, worked the bubbles out of the lines, turned it with the dyno, dropped the clutch and vroom vroom. No modifications from the original Kawasaki 250 Ninja kit and it fired up immediately.

There's a few things need sorting but the basics are there. It will not hold a steady low rpm and with the slightest whiff of throttle jumps to 6-8000rpm and the spark advances 30 odd degrees. Something has happened to it now and it only fires for a second when turning it over. The rotor may have come loose or maybe a bit of crap has got in the injectors. It did run for 10 minutes or so but with the generator rotor just perched on the end of the crank I wasn't doing anything adventurous.

I need to go over the logs a bit to see what is going on but I'm smiling for a bit now.

[speedpro]

Had a good look at the bike and thought possibly the crank pickup connector pins might have been touching the engine. I haven't fitted the spades to the connector properly yet as I was uncertain of the polarity. Bit of tape and all sorted. Made a fuel tank from an old turps container, purged the fuel system of air bubbles and gave it a go. It's just sitting on stands, put in 3rd gear, and the back wheel spun. It fires immediately.

First thing I noticed was that it had the same problem as yesterday where it would die if the throttle was closed but revved quickly with the tiniest throttle movement. I also noticed that the fuel PW was going to "0". To fix that I've changed the "fuel decal cutoff" rpm to max of about 5000rpm. Problem solved, now idles at about 4000rpm. Small manual adjustment needed there but no problem. Now if revved say to 7000rpm, when the throttle is released it goes all quiet as the fuel is cut and then as the revs fall below 5000rpm the noise resumes. The throttle response is amazing even with the heavy generator rotor perched on the end of the crank. Previous testing with the carbs fitted was with just a very small trigger on the crank and even then it was comparatively very sluggish though there was no airbox so the carbs weren't being helped at all.

My initial impression was that the tuning was going to be difficult but as Sketchy suggested I am starting already to get a handle on using the dropdown menus. I want to change the ignition timing as well for the lower rpm range over the full load range. I've already done it and the configuration is ready to load to the ECU. It was pretty straight forward, pulled up the ignition map, right clicked, exported to CSV, copied the value I wanted to all cells in one step, saved it, reimported to the software. It took less time than it took me to type about doing it.

There is also a fuel enrichment dependant on engine temp. I have the sensor attached to a convenient unused 6mm hole on the block. Even with the Yamaha water temp showing that it's all warmed up the sensor is only showing 45 degrees and the ECU is adding about 30-50% extra fuel. Easy to change though, pulled up the single line table and told it to add 0% extra above 30 degrees. As it warmed up it developed a patch where it didn't want to idle so well, so will add a bit of fuel just at 30 degrees.

Hopefully uploaded a video here of it running: http://www.youtube.com/watch?v=WIr65cBoHd0

Pretty stoked at the moment

[Drew]

Could the excessive throttle response, be the throttle position values being screwy?...If they are adjustable of course.

[speedpro]

Could the excessive throttle response, be the throttle position values being screwy?...If they are adjustable of course.

I actually like the throttle response now. Before it was more that it died with the fuel being cut off completely at any revs over about 1800rpm with no throttle and then with the smallest sniff of throttle it barked up again.

[F5 Dave]

Gee certainly doesn't sound like its doing those sort of revs does it? But I'm listening twice removed recording.

[speedpro]

Had a little explosion in the garage tonight.

Luckily it was just the bottom radiator hose. It seems that the clear plastic hose from Mitre10 isn't good enough. The motor was getting hot after running for some time while I was adjusting the ECU. It filled the garage with steam in a blink and made a proper bang sound. Parts of the garage floor are nice and clean now.

The engine is doing this thing where it hunts up to the "decal fuel cutoff" rpm then drops back as the fuel is cut and then it repeats. I've reduced the multiplication factors such as "warmup fuel" to zero above a certain temp and even started taking fuel out using the VE table. It got better and better but it looks like I might have got to the minimum injector on time. Definite improvement though. I'm trying to get a good stable idle so I have an idea where to go with the fuel and ignition. The low load/rpm values should roughly translate in the higher ranges.

One thing I like is the fuel multiplication factor. I haven't used it yet but it may be useful if I wanted to try some other type of fuel. Something to try later maybe.

Found a useful feature with the tables you can change "live". You seem to need the gauges displayed and then you open the table over them. The active cell is highlighted in yellow. I typed in new values in a couple of cells and could hear the engine note change. It'll be interesting on the dyno.

[Kornholio]

Cool thread... Not into buckets but this experimenting and stuff is quite interesting, was fascinated with Sketchy's thread(still think he should spend all his time racing superbikes but that's another story :) ) making his supercharger

Keep up the good work :scooter:

[Drew]

Had a little explosion in the garage tonight.

Luckily it was just the bottom radiator hose. It seems that the clear plastic hose from Mitre10 isn't good enough. The motor was getting hot after running for some time while I was adjusting the ECU. It filled the garage with steam in a blink and made a proper bang sound. Parts of the garage floor are nice and clean now.

The engine is doing this thing where it hunts up to the "decal fuel cutoff" rpm then drops back as the fuel is cut and then it repeats. I've reduced the multiplication factors such as "warmup fuel" to zero above a certain temp and even started taking fuel out using the VE table. It got better and better but it looks like I might have got to the minimum injector on time. Definite improvement though. I'm trying to get a good stable idle so I have an idea where to go with the fuel and ignition. The low load/rpm values should roughly translate in the higher ranges.

One thing I like is the fuel multiplication factor. I haven't used it yet but it may be useful if I wanted to try some other type of fuel. Something to try later maybe.

Found a useful feature with the tables you can change "live". You seem to need the gauges displayed and then you open the table over them. The active cell is highlighted in yellow. I typed in new values in a couple of cells and could hear the engine note change. It'll be interesting on the dyno.

Have you sorted out a decent crank angle sensor/rotor thing yet? Any chance of 'float' there?

Just thinking about the low speed 'hunting' you describe.

Unless it runs an idle stepper motor, I would look mechanical before the ones and zeros. Crikey, nothing as simple as a poor seal at the throttle bodies is it?

[speedpro]

I haven't sorted out the rotor yet. I have a rotor from a different model FZR250 with a different internal taper which is otherwise the same as the correct rotor. It's keyed to the crank but doesn't fit as far on to the taper as the correct rotor. When I say low speed hunting I mean between 4-6000rpm. I've sent a log and two tables I've mdified to Matt at Ecotrons. I'm hoping he has some suggestions. I've checked the throttle bodies are installed in the boots properly and they seem OK. They are a tight fit and probably don't need the clamps. I might have another look. Without the wideband lambda sensor it's difficult to see what is happening with the mixture, plus I haven't even installed the narrow band lambda sensors the kit came with. They aren't used in the early stages after startup so probably not really an issue at the moment.

[Drew]

Righto, I shall eagerly await the next installment.:niceone:

[Kornholio]

A few of us have these systems now. I thought it might be useful to have a separate thread to swap information. I'm just starting with mine on a 4 stroke twin that will eventually be turbo or supercharged, Rob has his 2 stroke single with triple injectors coming along, and Sketchy with his supercharged Honda clone.

I'm using a kit designed for a Kawasaki 250 Ninja. I already see a few possible problems with the triggering even though the FZR has 4 teeth on the flywheel the same as the Ninja, I'm not sure where the long tooth lies in relation to which cylinder is firing and then how many degrees after that the next one fires. On a 180degree twin the firing intervals are odd - 180deg and 540 deg. I'm sure it's configurable but I haven't got there yet.

[Dumb question]What sort of motor are you using? I see you have an FZR but I thought they were 4cyl and you have a twin... Some pics would be nice too. [/Dumb question]

Cheers

[Drew]

[Dumb question]What sort of motor are you using? I see you have an FZR but I thought they were 4cyl and you have a twin... Some pics would be nice too. [/Dumb question]

CheersIt is an FZR with two slugs chopped off...Literally.

I always meant to ask, why run the two right hand slugs? Did you want the 270° firing sequence for any reason?

[Pumba]

Knowign that we have discussed this before a while ago I dug up a thread from a few years back with a few pics for you Kornholio.

http://www.kiwibiker.co.nz/forums/showthread.php/11908-Wanted-Yamaha-FZR250-rolling-chassis

[speedpro]

Thanks for reminding me how long it's taken to get this far. Not long till it hits the track now. I've seen an even smaller turbocharger on a scooter site, hmmmmm!

[F5 Dave]

I was about to do that but saw I got beaten to the punch so deleted my post.

heck I remember this project back when you used to live in Auckland.:whistle:

[Kornholio]

It is an FZR with two slugs chopped off...Literally.

I always meant to ask, why run the two right hand slugs? Did you want the 270° firing sequence for any reason?

Wow, I instantly thought the outside pistons and keep the 2 middle ones... Wicked, can't wait to see some pics


Knowign that we have discussed this before a while ago I dug up a thread from a few years back with a few pics for you Kornholio.

http://www.kiwibiker.co.nz/forums/showthread.php/11908-Wanted-Yamaha-FZR250-rolling-chassis

Mint bro, like I said earlier I don't know fuck all about buckets but for some reason this intrigues me, maybe from when i used to tinker with old lawnmowers and chainsaws when I was a kid... Cool


Thanks for reminding me how long it's taken to get this far. Not long till it hits the track now. I've seen an even smaller turbocharger on a scooter site, hmmmmm!

Well done man :)

[speedpro]

Updated photos

[speedpro]

Going on my own instincts and what Drew said about a possible air leak I've been over the intake side pretty carefully. It all looked good and I recall taking a lot of care fitting the intake boots. In the end I backed out the butterfly stop screw all the way. It was a bit harder to start but now it idles at 1400rpm. It has no vacuum at idle. I have my old carb balancing gauges fitted with the MAP sensor off a t-piece to one gauge. If the revs are brought up a bit the vacuum climbs. With the bypass screws fully in, the motor will just about idle and a slight discrepancy on the gauges suggests the butterflies aren't perfectly synced so that might be tomorrows job. Then I'll adjust the bypass screws to balance it again and set the idle, though the screws don't seem to make much difference.

I knocked a bit of fuel out of it using the VE table. It kept on idling fine. It was fully warmed up and I've already reduced the warmup fuel multipliers to "0" anyway except at the lower temps. The main effect was it lost it's real sharp responsiveness so I've increased it again. It was running fine, I was just experimenting.

[speedpro]

Got a bit of info from Ecotrons about the idle setup. I was already going there anyway but nice to know. I did need to adjust the throttle stop screw. It's pretty sensitive. I've also ended up setting the idle to 2000rpm in software. 1400rpm worked but it seemed a little erratic at the lower revs. So I've set the idle in software and then adjusted the throttle stop to get it working sweet. It looks like the Ecotrons system uses the ignition advance to regulate the idle rpm. If I screw the throttle stop in too far it backs the timing off as far as even after TDC to try and keep the idle down. It works but makes it twitchy. It was far better with the throttle stop adjusted out until the ignition advanced to around 20 degrees. I could then blip it and it just settled straight back to a nice smooth idle without undershooting. Not having the ignition advance swinging wildly about probably helped here. Having the throttle stop screw out too far also seemed to promote hunting of the rpm as the ignition advance swept back and forth trying to control the rpm.

It's pretty sorted at the low rpm now, with no load anyway. Definitely time for the correct generator rotor so I can rev it up on the dyno.

I'm going to have to make an engine brake as well. I'll then be able to install the Lambda sensors, run the engine at set revs and loads, and let the system self-learn. Once that's done it seems that by changing the Eco/rich switch I can instantly switch from stoichiometric to max power rich. I don't need to actually measure the load, the MAP sensor and TPS will take care of which bit is being tuned and there is a table to show which bits have been tuned automatically. The neighbours are going to love that - 12,000rpm and various throttle settings, 14,000rpm and various throttle settings, 16,000rpm, 18,000rpm and so on. Might have to build a quiet pipe instead of the dump pipes on it now.

[speedpro]

First public outing was a failure with air in the fuel system. Bled it out with a new supply at home and away it went again. I'm going to have to make a little reservoir that is always full to feed the fuel pump. The main tank will gravity feed into that little one.

[TZ350]

I'm going to have to make a little reservoir that is always full to feed the fuel pump. The main tank will gravity feed into that little one.

Thanks for the tip, I will make sure I have a small header tank system too.

286609

This is a small header tank with breather that I made from a car fuel filter for the OKO carburettor, I will make something similar for the EFI version.

[TZ350]

Have you got one TPS feeding the two computers?

Yes ....

286974

This is how I connected the Ecotrons and Ignitec TPS wires together.

286975

The Ecotrons EFI TPS plug. I just spliced a (grey) wire and connector onto the white wire for the Ignitecs grey TPS input wire.

As Wobbly suggests, connecting the Ignitecs blue sensor earth wire to the 0V (green wire) side of the Ecotrons TPS might be a good idea too.

286983

Up dated as suggested by Wobbly.

[speedpro]

TZ and I had a bit of a chat about which fuel table is used when. Looking at his "load prediction table" it looked like it only ever looked at the TPS/rpm table. As a comparison I've looked at what I have for the 4 stroke and it's vastly different. Searching the manual - "Small engine EFI tuning guide - v2_6" for "weighting" brings up a description for the purpose of the table which seems to point to it being relevant when the throttle position is changing. My prediction table seems to split the difference 50/50 between the tables up to about 2000rpm and then only consider the MAP/rpm table.

[TZ350]

My prediction table seems to split the difference 50/50 between the tables up to about 2000rpm and then only consider the MAP/rpm table.

Thats very interesting, I will have to experiment with it.

[TZ350]

I checked with Matt, and know we know that Ecotrons EFI software for 2T's comes with only the TPS Based Load map functioning and the Volumetric Efficiency map disabled even though we can still see it.

289221

support@ecotrons.com
Re: Does a 2T ignore the VE map?

For the 2 stroke engine, it use A/N MAP in default and disable the P/N MAP.
Because usually the 2 stroke engine intake pressure change is very small, phase judgment is not very accurate.
You can log some data and send to us, if the intake pressure change is bigger, we can help you switch to P/N MAP.
Thx
Ecotrons Tech Support 001

[TZ350]

289313

Speedpro clued me into starting a run with the gauges then laying a map over them and the active cell would be highlighted in yellow. He also thought that it might be possible to change the settings on the fly.

I tried it tonight but could not figure out how to change the settings while the motor was running but being able to see which cell needs a tickle will be helpful. I got a few runs in before the dyno battery spat the dummy, I will change it out and have another go tomorrow night.

Not sure about tonight's results but one thing is for sure, my 330cc injectors are too big, I have ordered some smaller ones and its realy a two person job setting the EFI up. I need some way of videoing the screen so I can see which cells to adjust after a run and I can't fiddle with the laptop and keep the bike running at the same time.

[Drew]

Set the camera on the bench recording, looking at the computer and go about your bizzo.

I would have thought it was a two man job on the dyno anyway. Must be a bit of a juggling act to do everything by yourself.

Would it be much easier to put one of these injection set ups on a single cylinder four banger? Is it conceivable to make it direct injected by just hooking it up or would it all be different maps and shit?

Obviously it needs to run higher fuel pressure to overcome the compression.

[Grumph]

Direct injection is banned by both the FIA and FIM...but you never know, Billy may be prepared to ignore that too..

In fact, Drew, where it is used, the injection port is usually down the bore where it's covered by the piston well before TDC, so I'd doubt if a very high pressure would be needed.

There are good reasons for indirect injection on a 4 stroke though, not least charge cooling and reducing valve temps.

[Drew]

Direct injection is banned by both the FIA and FIM...but you never know, Billy may be prepared to ignore that too..

In fact, Drew, where it is used, the injection port is usually down the bore where it's covered by the piston well before TDC, so I'd doubt if a very high pressure would be needed.

There are good reasons for indirect injection on a 4 stroke though, not least charge cooling and reducing valve temps.I didn't realise the injection point was coverd by the slug. That would explain the funky piston shape I suupose.

[TZ350]

Well, in the end I didn't bother trying the EFI again tonight. I am going to wait until I get my new smaller capacity injectors.

289354

My current injector(s) are the Weber PICO IWP043 330CC units. Staged to fire one at low rpm, two in parallel at medium rpm and all three together at full load.

As it turns out, one by itself is to big for starting and running at light load off the throttle. At this point the injection on time is less than the 2ms minimum for accurate fuel control.

289355

I am going to try a set of these. They are half the capacity and this will effectively double the injection on time at start up and slow running and that will make it much easier to tune the injection map.

289356

The good thing is, all the injectors don't have to be the same size, you can mix and match to get the overall sizing that works best.

[TZ350]

Ok the word from Ecotrons is .....

Hi,
It supports on-the-fly function.

The variables which labeled “RAM_” support on-the-fly function, so you can tune the data while engine is running.

Step1: connect to ECU while engine is running.

Step2: tune the cell value of (RAM_MAP_LdTp_Tps_N), double click the cell and input the value, then press”Enter”, you can see a message on the lower left corner of ProCAL “ Write successfully”

Note: when you tune the data on-the-fly, please “Stop Measuring”. Otherwise it will not take effort.

And if the ECU power off, the data will be lost, so you need save the data and burn to ECU after you think the data is OK.


Ecotrons tech support BL

[koba]

Well, in the end I didn't bother trying the EFI again tonight. I am going to wait until I get my new smaller capacity injectors.

289354

My current injector(s) are the Weber PICO IWP043 330CC units. Staged to fire one at low rpm, two in parallel at medium rpm and all three together at full load.

As it turns out, one by itself is to big for starting and running at light load off the throttle. At this point the injection on time is less than the 2ms minimum for accurate fuel control.

289355

I am going to try a set of these. They are half the capacity and this will effectively double the injection on time at start up and slow running and that will make it much easier to tune the injection map.

289356

The good thing is, all the injectors don't have to be the same size, you can mix and match to get the overall sizing that works best.


Golly, the size of that exhaust port is quite graphic there!

[TZ350]

290088

When a fuel injector on a four stroke fires, a mist of fuel forms behind the inlet valve. And when the inlet valve opens that cloud of fuel is blown into the cylinder.

Four stroke EFI components are readily available and on a two stroke people (and I was one of them) often try to mimic a four stroke by fuel injecting into the two strokes inlet but I have since learned that to truly mimic the action of the fuel cloud behind the four strokes inlet valve one has to inject into the transfer port of a two stroke and that the end point of the injection pulse needs to be timed to finish as the transfer port closes.

It all makes sense when you think about it for a bit. If the start of the injection pulse into the transfer port is a little ahead of the transfer port opening (or open) then that effectivly mimicks the action of injecting behind the four strokes inlet valve.

290089

on a two stroke at 12,000 rpm you have less than 5ms and 2 of those are used up getting the injector open.

If you follow the links below you will find four posts with dyno graphs and video of two successful 2T two stroke fuel injected bikes.



289908289909

With Flettners guidance and his example of two very successful working bikes, one on E90 and the other on pump gas I have been encouraged to have a go myself.

The first lessons I have had to absorb are that the timing of the Injection end point is critical on a two stroke and should be timed to end at transfer port closing and the fuel should be injected into the transfer ports, either counter stream like the YZ250 or across the port like the Kawasaki but definitely not straight into the inlet or the crankcase itself. To be successful the full fuel charge has to be inducted into the cylinder on each cycle otherwise you get rich/lean cycles and poor running.



Performance Fuel Systems has great technical articles about fuel injectors. http://performancefuelsystems.com/tech.htm
(http://performancefuelsystems.com/tech.htm)
290013

An injector does not instantaneously snap open, it take a finite amount of time to reach full flow. 2ms (2 thousandths of a second) is the rule of thumb, below that, the flow is mostly non-linear and erratic.

Thankfully its better on the closing side as the fuel injection pressure helps with closing the injector’s needle valve so closing is much more rapid than opening.

A little math ..... 8,000 rpm / 60 = 133 rps x 360 deg = 48,000 deg sec / 1000 = 48 deg/ms

So at 8k rpm the crank turns 48 degrees in one mille second or 96 degrees in the time it takes to open the injector properly (ie 2ms).

2ms @ 8k rpm = 96 deg of crank rotation
2ms @ 10k rpm = 120 deg of crank rotation
2ms @ 12k rpm = 144 deg of crank rotation
2ms @ 14k rpm = 168 deg of crank rotation

If the transfers open 115 deg ATDC then they are only open for 130 deg total.

So if at 12k rpm it takes 144 degrees (2ms) to get the injector fully open and another 72 degrees (1ms) to deliver sufficient fuel then the injectors pulse width is 3ms and it is energized for 216 degrees which is way more time, than the transfer port is actually open.

Thankfully most of the early fuel will be a cloud hanging around in the transfer duct waiting to be blown into the cylinder when the transfer port opens, much like the cloud of fuel waiting behind the inlet valve in an EFI four-stroke.

290012

Green line is the transfer port duration, red line is the pulse width of the injector, in this drawing it takes 2ms to ramp up and another 1ms to deliver the full fuel load. So the injector is energized for 3ms or 216 degrees or for longer than the total transfer duration at 12,000 rpm. The right hand side shows the partial fuel cloud forming in the transfer duct as the injector opens and before the transfer port opens. Thankfully the injector turns off faster than it opens.

Flettner makes the point that its important, in fact the whole key to successfully fuel injecting a two stroke, to have the injection period timed to end at the transfer port closing.

[speedpro]

Pg 91 in the manual. I knew I'd seen it somewhere.

[speedpro]

It gets a bit more complicated. There the 2 tables that have values, one for MAP vs RPM and one for TPS vs RPM. How much weight is given to each is dependant on RPM and a value in another table. See the manual below and the screen shot of my default table. Easy to get lost I think. Note that the manual refers to the VE table. Values in here affect the injector pulsewidth in conjunction with the MAP table and other sensors such as inlet air temp.

[TZ350]

There the 2 tables that have values, one for MAP vs RPM and one for TPS vs RPM. How much weight is given to each is dependent on RPM and a value in another table .... my default table.

290294

Speedpro, am I understanding this right, in your table, above 98% TPS at 3,000 rpm and above 10% TPS at 12,000 Ecotrons moves from the VE table and looks at the Alpha-N table.

[speedpro]

290294

Speedpro, am I understanding this right, in your table, above 98% TPS at 3,000 rpm and above 10% TPS at 12,000 Ecotrons moves from the VE table and looks at the Alpha-N table.

That's what I understand from the manual. The table description is misleading.

[speedpro]

Interesting rereading the tuning manual how much more relevant some settings become with a little knowledge

[TZ350]

290487

Hi Speedpro, is this the two-way button for making map changes on the fly?????

[speedpro]

Bit hard to see in the photo. If you are changing the TPS table, or any other that starts with "RAM" any changes are made in real time to the values in the RAM on the ECU. You would want to save them at the end of the session and I've been doing that by simply disconnecting and reconnecting and burning to the ECU when prompted.

One thing I have found useful is to change the scales on the gauges. Right click in any gauge and enter new values for the min & max of the scale. Makes it a bit easier to see what's going on.

[TZ350]

Thanks ... my map does say "RAM" but there is no obvious two way indication, I will have to pay more attention to it next time.

[speedpro]

Pg 96 in the tuning guide

[TZ350]

290739

Advanced calibrations setup with two injectors

290736 290735

FUELPW1 active and the oscilloscope shows output at injector 1

290738 290737

FUELPW2 active but the oscilloscope shows no output at injector 2

I have just tried a really old version of the ProCal software and calibration files, they worked, so its some sort of software glitch in the newer version of software or advanced calibration file they sent me.

[speedpro]

#6 FZR125/2 running with the Ecotron EFI. First run after setting the engine capacity to 125cc from 62.5cc and reverting to default VE and TPS maps. Only made one change to the warmup table and changed one small block on the VE table to reduce the fuel being injected. It was really obvious there was way more fuel being injected with the new engine capacity as the injector pulse widths were up. Plenty to do but very encouraging.

http://youtu.be/x0quPqr3wkE

[speedpro]

More time on the dyno and a very important reminder of how the tables work. The dyno does not record engine rpm so I wanted to match 10,000rpm to a particular speed. To do this I set the TPS/RPM table value at 10,000rpm and 32% throttle to about 1/2 what seemed a good value, as tested. The next run should have seen it fall flat on it's face at 10,000rpm. What actually happened was not much. It ran through the load cell as if nothing happened. I then set the values at 10,000rpm for the TPS settings above and below 32% to the same value and did the run again. This time it ran into a wall at 10,000rpm.

This was a good reminder that the software does not read the value "only" at the highlighted cell but blends the values in the cells around to determine the correct fuel requirement. It was interesting to see the fuel pulse width slowly decrease as the load cell with the seriously reduced value was approached.

So all the effort so far has just been tossed. That is because I have only been altering the one row for 32% throttle. The rows above and below are markedly different. I copied the values from the 32% row to the rows above and below and the engine would not run at 32% throttle. I have to think of a new tuning strategy. I'm thinking of concentrating on a particular cell, say 32% TPS at 10,000rpm, and altering all adjacent cells to the exact same value initially and testing until I have the optimum value then picking another cell and so on. Once I have a few cells mapped I can blend the intermediate cells after which it would need to be done again. It's going to be a mission.

[TZ350]

Very interesting, thanks. The Ecotrons system looks to be quite technically proficient.

[speedpro]

As per the #6 thread I have fitted a Wideband(WB) O2 sensor. This is a Link Electrosystems standalone system that indicates mixture on a LED scale. Previously I had done a few dyno runs at small throttle settings and determined that I needed to reduce fuel at those low settings. This time when first fired up from cold it was quite lean and difficult to start and keep running, due to the base VE map fuel having been reduced which meant the "warmup" table multiplication factor had to be increased. I did that and the motor immediately settled down. Once warmed up I just held the throttle at small settings and adjusted the table to get a good indication. I spent about an hour doing this and finally ran it up in 6th gear on the dyno, but still at small throttle openings so it took longer to progress through the VE table load cells. I kept making adjustments making sure I blended in adjacent cell values. The end result is that it is pretty sweet up to about 12,000rpm and up to about 20% throttle. Any values I've adjusted in the VE table have all been reduced from the default so before further testing I will reduce the remaining values a similar amount. A couple of times I ran it further up the scales it blubbered and I got a rich indication on the O2 sensor.

One thing that became obvious last time on the dyno and which was also causing grief in this session is that if the ignition timing retards for any reason with very small throttle openings then the mixture indication goes rich. This is probably due to poor combustion with ignition sometimes being ATDC and therefore reduced swirl, and therefore flame propagation, resulting in higher emissions. If you don't notice the timing retarding it makes tuning difficult. I will look to stop that for future sessions.

The WB sensor is a must I would say if you are fitting one of these systems. Ideally you would record the WB output with the Ecotrons software so you could play it back and make adjustments. So far though it looks entirely doable without recording the output.

[speedpro]

I've been running the bike on the dyno and monitoring mixtures with a Link WB O2 sensor. I've been making adjustments to the VE table for the small throttle settings at lower revs, up to about 10,000rpm. It was coming along nicely with the motor reacting to throttle movement very nicely at any revs and the Lambda indicator fluctuating back and forth but in a good range. This afternoon I decided to try tuning at the 32% throttle position where it transitions to the TPS table over 4000rpm. The motor was revving out OK but the Lambda indicator was out of range and it wasn't obvious in which direction. Because of that I decided to install the Ecotron NarrowBand(NB) Lambda sensor as that would give an indication on the gauge on screen which direction the fuel was in, rich or lean. This worked WAY better than expected. The gauge indicator transitioned back and forth as expected but even though it is a NB sensor and not supposed to be progressive it clearly is. Small adjustments resulted in small changes to the indication so I could see when adjustments were approaching ideal.

I only have one bung fitted to the exhaust pipe and therefore only fitted one O2 sensor. My son spotted that the fuel injection pulsewidths were different. We figured out that this is because the #2 O2 sensor input "without" the sensor fitted is dragged to .45 which is seen as optimum but the #1 input was seeing rich or lean signals and the ECU was trying to compensate by adjusting the injector pulse width. It seems it can only adjust it by up to .3mS but that is enough. I've been making changes manually of .1 to adjust the mixture. It also means individual channels are monitored and adjusted individually. Pretty cool.

An annoying problem that was affecting efforts to tune the lower load settings and revs was the systems habit of backing the timing right off, 15deg ATDC sometimes, which made the revs drop off and the motor struggle and then when you gave it a bit more throttle it'd rev above where I was interested. This is the systems attempt to control the idle speed with ignition advance. There is a ignition table for the minimum advance/retard setting according to load and RPM. I set it so that the minimum timing possible was 7.5deg advance, the same as the default advance at idle. Now even though it backs off at times the revs can still be controlled by the throttle making it possible to monitor and adjust.

[TZ350]

http://www.vemssupport.com/forum/index.php/topic,97.0.html

Before calibrating an engine, it is first useful to have some concept of what you are trying to control. The following is a fairly brief overview of the internal combustion engine, which will hopefully give you a basic understanding of some fundamental principles and terminology, so that when you change a number in a box on your laptop, you have some idea of the effect it is having on the engine.

""Fuelling Theory ... Lets start with the theory then. We are concerned with spark ignition gasoline engines here. I am only going to cover gasoline, since Diesel is for trucks and diggers, and alcohol is for drinking and drag racing.""

http://195.159.109.134/vemsuk/forum/index.php/topic,97.0.html


(http://195.159.109.134/vemsuk/forum/index.php/topic,97.0.html)292228 (http://195.159.109.134/vemsuk/forum/index.php/topic,97.0.html)
(http://195.159.109.134/vemsuk/forum/index.php/topic,97.0.html)

[TZ350]

Ecotrons has a very clever self tuning feature where you tell the map what Lambda you want at what RPM and the ECU will read the ALM O2 sensor and adjust the mixture for you.

But :o you do have to ask for the right Lambda value for the engine. And this is where I went wrong tonight, I made the lower end to rich and eventually after a lot of auto tuning work the motor could not pull the skin of a rice pudding and drag itself into the power band.

My mistake was asking for too rich a Lambda at low throttle settings, and having the bike struggling to pickup on the dyno. I had made the map 0.85 Lambda everywhere, I should have stuck with the default map that had Lambda 1 at low RPM and dropping to Lambda 0.85 - 0.82 at max power.


Do you mean low throttle settings or full throttle low rpm? Regarding the latter, you should be able to run Lambda 0,85 (and richer) without 4-stroking from about 3000 rpm to top rpm if ignition timing is in the right ballpark. Also, a properly designed combustion chamber (high msv type) should make tuning the EFI easier for you as it's less sensitive to 4-stroking.


I know it and you know it, but I can't repeat it often enough: lambda does not tell you rich or lean; it only tells you how much oxygen it sees in the exhaust gases.

At low throttle settings the engine will occasionally miss a combustion cycle, which sends all inhaled oxygen straight into the exhaust.

If you try to adjust the resulting lambda readout by jetting richer, you will smother the engine wit a very rich mixture (and cause even more misfiring).

Haufen and Frits, Thanks for the Heads-Up.

[speedpro]

I've had it explained by a support guy and Matt and this is how it works. You use the ALM WB lambda device in conjunction with their "autotune" function to tune the engine in ECO mode. In ECO mode the target lambda is "1". The system makes adjustments until it determines what fuel injector pulsewidth is required to deliver the correct amount of fuel so the engine runs at lambda=1. When you switch to POWER the system looks to the "desired lambda" table. The fuel pulsewidth calculated in ECO is divided by the value in the "desired lambda" table and the new fuel pulsewidth is found.

Example: In ECO mode at a certain load it is found that the fuel pulsewidth needs to be 3mS to obtain a lambda of 1. In POWER mode at this load there is a value of .9 in the desired lambda table. 3/.9=3.33. 3.33 is the pulsewidth for a lambda of .9 at this load. POWER is open loop and relies on the tuning being right in ECO for a lambda=1.

I have also been getting annoyed when using small throttle settings where the system seemed to be trying to get the motor to idle. Turns out that there was a value where if the TPS was at less than 2.5% the system thought you wanted the engine at idle. I've set it to 0% TPS for idle. Now when I give it even .1% TPS it runs sweetly to some rpm without the timing backing off trying to reduce the engine rpm to idle. Makes it easy to set the low rpm, low load mixtures.

With the NB sensor connected to the ECU it still trys to autoadjust with the result that it cycles back and forth rich to lean. With the standalone WB sensor and no NB sensor it isn't a problem. Only trouble is I've figured that the WB sensor is not ideal. Hopefully Ecotrons can tell me how to disable the autoadjust feature.

[speedpro]

It's taken a while but I've decided that I need to use the "autotune" feature. The difficulty is holding the engine at a particular load and rpm for the 10 seconds or so required for autotune to determine the correct fuel load. An Eddy current dyno would do it but they're a bit pricey to buy/build/borrow. So tomorrow I'm going to pick-a-part to see about getting a rear hub assembly from maybe a TX5i or similar. I just need to have a roller/wheel to sit the bike on and be able to put the brake on to load the engine. There is no real need to measure the power. The only thing I haven't decided is just what I'm going to bolt to the hub that the bikes rear wheel will sit on. Any ideas?

Hopefully this will enable the maps to be tuned for Lambda=1 and then I can switch to POWER mode and adjust the "desired lambda" values for best power on the dyno.

Hopefully I'll get an order for the ALM, meter, and a 3bar MAP sensor off to Ecotrons tomorrow.

[speedpro]

On the dyno, with one NB O2 sensor installed and connected to the ECU one cylinder pulse width was always being altered by the closed loop feedback. This was a real pain for me as it made it nearly impossible to determine what was the ideal value in the tables. One thing I asked for and Ecotrons helped with was having one O2 sensor connected but having both pulsewidths adjusted by the feedback. This was better but the system still cycled the fuel pulsewidths back and forth between rich and lean. So I asked how to disable the feedback whilst still monitoring the sensor output. They sent a new ".cal" file with the feedback disabled. By doing a comparison with the last ".cal" file they sent I can see which 2 values they have changed. It's easy enough. What is annoying is that the 2 values descriptions don't indicate they would have this effect at all. I haven't tried it on the dyno yet but it should be a lot easier to tune now.

Things I've done -
changed the " ignition advance" maximum retard from about 15deg"A"TDC to 7.5deg BTDC(used to control idle speed),
changed the minimum throttle position below which it expects I want idle speed from 2.5% to 0%(to stop it backing the ignition off at small throttle settings),
enabled one O2 sensor to provide feedback for both cylinders,
then disabled O2 sensor feedback.
increased the maximum speed the software will allow the engine to run from 14,000rpm to 16,000rpm.

I'm hoping it'll be easier to tune as the features that alter the fuel injected, or the lambda reading, have been disabled. Time will tell, hopefully next weekend.

A water pipe under the bathroom handbasin decided to spring a leak Sat night so I spent Sunday sorting it out properly. Waste of a good Sunday.

[TZ350]

A guide to installing and using the Ecotrons electronic fuel injection ProCal tuning software based on the experiences of a complete newbee with no previous EFI experience.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/Bubbles-2_zpsb58f2623.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/Bubbles-2_zpsb58f2623.jpg.html)

The Ecotrons fuel injection system is my first experience with EFI. Sure, I had seen fuel injectors and mass air flow meters before and had some idea of how they worked but I was really a total newbee to EFI when it comes to installing one and setting it up.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/EFIKitandWiringHarnes_zps9419d2bd.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/EFIKitandWiringHarnes_zps9419d2bd.jpg.html)

I brought the Ecotrons single cylinder Small Engine Kit with two fuel injectors, the kit is easy to put together as it comes with its own wiring loom and everything is labeled.

Hardware installation is covered in the manual very well but I found getting started with the software fragmented and a bit confusing.

My kit was for a 2T - two stroke and I started with the VE table as you do, after two weeks of frustration it was pointed out to me that 2T's dont use the VE table.

One obscure line in the 100+page installation manual about 2T's not using the VE table was a bit inadequate I think and it was very annoying wasting so much time with a map that in every way looked like it worked but was internally disconnected.

If the VE map was not to be used it should have not been accessible or at least I should have been better advised when I received the kit.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/2strokesetup_zpse8c87ffa.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/2strokesetup_zpse8c87ffa.jpg.html)

This little gem is all that there was in the manual about 2T's only using the Alpha-N or TPS based Load map.

Anyway having had a winge, I now have to say that the Ecotrons Support Team have been very helpful.

I don’t have any experience with any other good EFI units like Mega Squirt or the Link, to compare the Ecotrons system too, the others I have been told, have software that is less confusing and easier to use.

But my impression is, that while the other EFI systems have a simpler and more polished user interfaces the Ecotrons system goes much further and allows you to really get your hands dirty with a myriad of tuning detail that the others don’t allow you access to.

There is much more to EFI than just VE tables and Alpha-N maps, and I think a student of EFI could learn a great deal with the Ecotrons system.

Being an EFI newbee and not so hot with computers either, the first confusing thing I encountered was, when trying to run the Ecotrons ProCal install Wizard, it had the “D/ drive as their default drive. I had to change this to the more normal “C/, sure its simple but the error messages about insufficient disk space were a little confusing at the time.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/Cshouldbedefaltdrive_zpsb7bda760.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/Cshouldbedefaltdrive_zpsb7bda760.jpg.html)

Once ProCal is installed there are two important files to know about, the “a2l” file which I think is the software for running the EFI’s CPU and “cal” files which hold all the calibration information like the tables for the VE and Alpha-N maps and advanced calibration information like the minimum injection time allowed.

There are different a2l files for the different hardware setups like the EFI system for twin cylinder 4T’s has different hardware and a2l file compared to a single cylinder 2T.

ProCal which I guess means professional tuning software works with any of the different Ecotrons "a2l" files and hardware options in conjuction with a calibration "cal" file for that particular EFI/hardware setup.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/a2landcalfiles_zps23f87260.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/a2landcalfiles_zps23f87260.jpg.html)

Having installed ProCal you get going in the normal way. Ctrl O to open a file and Ctrl S to save your tuning work.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/2startusingProCal_zpsfb4fa395.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/2startusingProCal_zpsfb4fa395.jpg.html)

First step is to load the a2l hardware file that came from Ecotrons with your EFI kit.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/firstselecta2lfile_zps27ad87ca.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/firstselecta2lfile_zps27ad87ca.jpg.html)

Second step is to load the calibration cal file that came with the kit. There may be just a plain cal file or there may also be cal files for Start Auto Tuning and Auto Tuning Finished. Anyway this is where you load the appropriate cal file.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/nextselectacalfile_zpscc21ad1b.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/nextselectacalfile_zpscc21ad1b.jpg.html)

You can save your tuning work

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/savingyourtuningwork-1_zps92f7b7a9.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/savingyourtuningwork-1_zps92f7b7a9.jpg.html)

and give it a unique name or save it to an existing file.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/savingyourtuningwork-2_zps0bd1f817.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/savingyourtuningwork-2_zps0bd1f817.jpg.html)

It will appear in the directory structure. Later you can combine them but I have not done that yet.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/savingyourtuningwork-3_zps8cb86091.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/savingyourtuningwork-3_zps8cb86091.jpg.html)

After you have done a bit of tuning work you may have saved some different tuning options for your EFI setup.

You can have quite a few different cal files.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/lotsofcalfiles_zps05334512.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/lotsofcalfiles_zps05334512.jpg.html)


Hopefully all this will be a help to anyone else trying to get their head around the ProCal file and directory structure.

[TZ350]

Maps and Tables

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/AirSystem_zps761c5233.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/AirSystem_zps761c5233.jpg.html)

The two big tables are the VE (volumetric efficiency) table and TPS based load mapping (Alpha-N) table.

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/VETable_zpsd72ccd8a.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/VETable_zpsd72ccd8a.jpg.html)

4T’s - four strokes, mostly use the VE table in conjunction with the TPS table. One of the VE tables inputs is from the MAP (manifold absolute pressure) sensor and the VE table is utilized at low throttle openings.

The Load Prediction Weighting table defines at what RPM and TPS that the EFI system swaps from using the VE table to the TPS table.

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/TPSBasedLoadMap_zps17203966.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/TPSBasedLoadMap_zps17203966.jpg.html)

2T’s – two strokes have such highly fluctuating pressures in the inlet tract that it confuses the MAP sensor. So a 2T can’t utilize the VE table and so only runs the TPS load based (Alpha-N) table.

Ecotrons ships its 2T – two stroke EFI systems with the VE table disabled. It can be a bit of a trap because you can still access the VE table and make changes to it but they have no effect. It can be a bit confusing.

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/AddAdvancedCalibrations1_zpsda212834.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/AddAdvancedCalibrations1_zpsda212834.jpg.html)

Add Advanced Calibrations. This is where you get to play with things like injection end time and control the way a staged injection system swaps between injectors.

You can build and save your own selection of variables from the vast array of variables and their default values that make up the EFI control software.

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/AddAdvancedCalibrations2_zps63c03f83.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/AddAdvancedCalibrations2_zps63c03f83.jpg.html)

Click on a variable to see a description of its function.

This one defines where the injection cycle is to finish while cranking over to start. There is an endpoint during start and an end point map. Ecotrons works backwards from that point and calculates where to start injecting. This is handy because on a transfer port injected 2T – two stroke you want to end the injection cycle as the port is closing.

Click OK to access the calibration variables.

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/AddAdvancedCalibrations3_zpsc6bce4a5.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/AddAdvancedCalibrations3_zpsc6bce4a5.jpg.html)

Minimum injection times and breaks between injection cycles can be manipulated to change the point where the injectors swap over and then work together, ie, 1 swaps to 2 then 1 and 2 work together.

The Fuel System

http://i1290.photobucket.com/albums/b522/TZ350AB/Maps/FuelSystem_zps17e31135.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Maps/FuelSystem_zps17e31135.jpg.html)

Start Conditions:- defines at what RPM the Start Fuel Factor ends, I set mine at 3,000 rpm for starting my 2T which idles at 3.5k.

Start Fuel Factor:- is the enrichment multiplier used during cranking when starting the engine. So things don’t get to rich during development I set this to 1 throughout. Makes things a bit hard to start but with it set to 1 it does not confuse development of the main map. Same with After Start and Warm Up, which I initially set to 0.

[TZ350]

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/Nails_zps3b252e50.png (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/Nails_zps3b252e50.png.html)

If you have not broken any nails getting here then its time to record and playback data to see what is going on and where we can improve things.

To record any data we need to be connected, the bottom left red thing needs to be green

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/2-Start-StopMeasuringandRecording_zps1cc67fad.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/2-Start-StopMeasuringandRecording_zps1cc67fad.jpg.html)

F8 measures various inputs like RPM, TPS and Engine Temperature, the gauges display the results. F9 records data from a pre determined list of variables and F11 stops the measuring and recording process.

The recorded data files are held in the “Record” sub directory.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-3_zps9fb77a72.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-3_zps9fb77a72.jpg.html)

Each time you record some data ProCal creates a new time/date stamped sub directory

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-1_zps6491e5ed.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-1_zps6491e5ed.jpg.html)

PlayBack

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-4_zps06bf6d57.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-4_zps06bf6d57.jpg.html)

Whenever you go to play back data, ProCal opens in the last directory to be played back.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-11_zpsaebe920c.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-11_zpsaebe920c.jpg.html)

So if you have recorded some new data you will have to go back up a level

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-12_zpsa3a48505.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-12_zpsa3a48505.jpg.html)

and select the latest directory.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-5_zps7d4ee943.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-5_zps7d4ee943.jpg.html)

There are three data files, one for data recorded Syn (continuously), and at 20ms and 100ms intervals.

Open a data file and everything recorded in the file will be displayed, it can be a bit of a jumble.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-6_zps901ad8da.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-6_zps901ad8da.jpg.html)

Top right you can define a time window, I use 0 to 20

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-7_zps8e903eb9.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-7_zps8e903eb9.jpg.html)

0 to 20 really spreads the plotted data out and covers a little more than the area of one dyno pull.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-8_zps31723589.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-8_zps31723589.jpg.html)

You use the slider in the middle top to select an interesting part of the plot.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-9_zps06183df5.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-9_zps06183df5.jpg.html)

Use the Clear/Show all Signals button to clear all the data then click the variables you want to study. A “V” will appear against the variables being displayed.

You can also use the cursor just like in an Xl spread sheet to re size the display area and data field columns so you can read the variable names.

Use the Show/Hide Cursor button to display two cursors. The cursors can be moved around to measure and compare different parts of the plot. The different variable values are displayed as the cursors are moved.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-13_zpsfe5f48a5.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-13_zpsfe5f48a5.jpg.html)

You don’t have to be stuck with the default variables to record and display, you can make up your own list, There are 100’s to chose from.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-14_zps1b7d6afa.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-14_zps1b7d6afa.jpg.html)

Click on a variable and its description will be displayed in the bottom left corner. You can add or delete as many variables as you like but there are processing time/band width limitations to the total amount of data that can be processed at once. The manual explains this point in detail.

http://i1290.photobucket.com/albums/b522/TZ350AB/Ecotrons Recording/PlayBack-15_zpsab8d24a6.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Ecotrons Recording/PlayBack-15_zpsab8d24a6.jpg.html)

When you have built up your own data variables list it can be saved under its own unique name. You can have as many data variable lists as you like to record things in different ways.

[TZ350]

Exporting map data to Excel and re Importing the Data file.

All the maps can be exported to Excel as a CSV (comma separated variable) file. When data is imported back into ProCal it has to be in the CSV format. It’s the same method for Start – After Start – Warm Up – VE and Alpha-N or any other table.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap0_zps0dac5181.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap0_zps0dac5181.jpg.html)

Exporting the Alpha-N or as ProCal calls it, the Tps Based Load Map which they call Ram_Map_LdTp_Tps_N map

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap1_zps811b2540.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap1_zps811b2540.jpg.html)

Double Left Click

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap2_zps5eee85e9.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap2_zps5eee85e9.jpg.html)

And by default it will be saved into the C/Program Files/Procal directory

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap4_zpsc1cf3e3b.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap4_zpsc1cf3e3b.jpg.html)

And automatically opened in Excel in CVS format. CVS is a Comma Delimited format.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap5_zps6566363a.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap5_zps6566363a.jpg.html)

You can use the normal Excel math functions to manipulate the data.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap6_zps4d76691b.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap6_zps4d76691b.jpg.html)

But when you have finished you have to be careful to delete all the extra cells as ProCal is expecting a certain table size and will chuck up if there is any extra or missing data.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap7_zps3bb60c2a.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap7_zps3bb60c2a.jpg.html)

Save the file in CVS format. Now this is where it gets a bit tricky as Excel tries to save the file in “My Documents” and it really needs to go back into the sub directory “C/Program Files/Procal so you will just have to change directories.

Once its saved and Excel is closed you will be back in ProCal.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap8_zpsb3197a7b.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap8_zpsb3197a7b.jpg.html)

Double left click

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap9_zpsb76af2ed.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap9_zpsb76af2ed.jpg.html)

And Import the modified map file.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap10_zpscffdb44a.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap10_zpscffdb44a.jpg.html)

The area you changed will show in Red.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap11_zps6a1020e7.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap11_zps6a1020e7.jpg.html)

Save the new map.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap12_zpsa682cb15.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap12_zpsa682cb15.jpg.html)

Now when you save the new map, the old Excel CSV file is visible in the ProCal Director but the new Tps Based Load Mapping data you created goes into the Beast-3 2ing Cal File that all the calibration changes have been saved to on my project.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap13_zps0b85fa4f.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap13_zps0b85fa4f.jpg.html)

To change a single value, double left click its cell.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap14_zps827ac7e8.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap14_zps827ac7e8.jpg.html)

Change its value and hit “Enter”. The new value will show in Red.

Save the change with Ctrl S or the Disk symbol at the top left corner.

http://i1290.photobucket.com/albums/b522/TZ350AB/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap15_zps0f3536b7.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Exporting and Importing Data/Ram_Map_LdTp_Tps_Nmap15_zps0f3536b7.jpg.html)



Lastly "Burn" your new changes to the ECU. Well you will need to connect first of course.

[husaberg]

That's a damn nice set of posts Rob.......

[speedpro]

I need to order an ALM and a couple of injectors. Rob is after some stuff as well. If anyone else wants to order some Ecotrons stuff shortly let me know and we can combine freight. Otherwise it's $50+- just for freight

[F5 Dave]

I need to order an ALM and a couple of injectors. Rob is after some stuff as well. If anyone else wants to order some Ecotrons stuff shortly let me know and we can combine freight. Otherwise it's $50+- just for freight
Have you used YouShop? Works well.

[TZ350]

Hi Speedpro, this is what I need

293756

Two of these 128g injectors

293755

And two lengths (1m??) each of the blue and clear fuel line that comes in the kit and one 25l pump.

[TZ350]

.

Posted so that those who want to try their hand at 2T EFI and Frits 24/7 concept can know their ambition is a realistic possibility.

There are a lot of good EFI ECU's around and Ecotrons sells inexpensive kits and parts, they are worth a look.


Riley Will of BRC is already achieving good results with EFI and so is Roland Holzner of Modena engines in Italy. The experimental 24/7 engine does not seem to care about the obligatory 30 mm inlet restriction.

Frits has posted some pictures of a working 24/7 setup.

<iframe width="560" height="315" src="http://www.youtube.com/embed/ifSEql1X4R0" frameborder="0" allowfullscreen=""></iframe>

EFI Kawasaki BigHorn running transfer port injection and E85. Runs to 8,000 rpm

Some more Youtube clips of transfer port injected 2T's
http://youtu.be/eleqBGvOM4M
http://youtu.be/hOGZ5llowoU
http://youtu.be/1YG9ko8-Nwk
http://youtu.be/UEQli7nuak4
GerbilGronk is worth a Youtube search.

I have been working on a EFI transfer port injection system of my own but trying to take the concept to 12,500rpm.


306944 Pumper

With a pumper carb this engine reliably made 28hp at 12,250 rpm, with EFI, 24hp at 11,500rpm is the best so far and the EFI is short about 1,000 rpm.

306943 EFI



I think that its becoming obvious that with transfer port injection, matching the timing of the injection cycle to the transfer port open period is vital.

I am finding transfer port injection above 9,000rpm is very difficult and I need to find another way to get to 12,500+rpm.

Below is an example of 15,000 rpm Inlet Port Injection.


Husa put me onto this post in PitLane http://translate.google.co.nz/translate?hl=en&sl=fr&u=http://www.pit-lane.biz/t839p15-technique-2-tempset-l-injection&prev=search

It talks about split injection where a injector fires every second revolution, it may be the way forward. Husa reminded me that he had suggested it to me before ...

Gentlemen,

2 years ago I did an Indirect EFI project on a 125cc Disk Valve Kart Racing Engine. I used a Vortex FC engine which produced 49HP carbureted. With our EFI, it made 55HP!!! The engine was very easy to start and the tuning was very simple. Here is how I did it:

Rather than attach sensors to figure out the everything for me, I went with information that was known to me. I have been tuning Del'Lorto carbs for years and have used their needle charts along with various softwares that calculate Comparative MainJet Sizes at 10% throttle increments. I used this information to calculate an initial map for the injectors. I did a test on the carbureted version at each throttle position to note the EGT that was giving the correct performance. Once running with the EFI i tried to tune it to achieve the same EGT numbers as the carbureted version.

In total I ran for 3 hours on the dyno and ended up with 10% more power everywhere!

The only sensors I used were Throttle Position, Engine RPM, Crank Angle, and Water Temp for initial start up enrichment.

How did I get an injector to fire every cycle at 15000 rpm?????? I didnt! What I did is used a Janvey 41mm butterfly throttle body with 2 injectors on the engine side of the butterfly. That way when the throttle is closed, fuel still feeds the engine to lubricate it like a Pilot Jet would do. To get 15000 RPM, I had each injector firing at alternating engine revolutions. Thereby the injectors were seeing 7500 pulse at 15000rpm of engine speed. I tricked them into thinking this was a 2 cylinder 4 cycle engine firing in Tandem.

In total I spent $1600.00 in componentry to validate my "Simple EFI" idea! I will be doing more tests this winter and will be track testing in the spring. We are workind on the miimum battery requirements and packaging.

I used 2.5 Bar of pressure and will be testing more. I chose a disk valve engine for the symmetrical inlet timing. I used a valve the opened at 137 degrees BTDC and closed at 87 degrees ATDC. I started firing the injector 10 degrees earlier on the opening and stopped the injector 10 degrees after the valve closed.

Upon engine disassembly it was noted that the lubrication seemed to be better dispersed thru-out the engine (only an observation). The engine would start at less than 800 rpm of crank speed and would instantly accept full throttle load from 1200 rpm and up!

The only hurdle I see to over come is the packaging.

I am confident that my way of giving the ECU the MAP rather than having the ECU calculate the map is why I was successful. We have tuned by EGT for years and continue to see the relevance when using EFI in correlation to EGT. The increase power came by better fuel atomization. It stands to reason due to the limited time "Tuning" the system that even more power gains are to be realized with more work and data collection/analysis.

I am posting this information so more people will try this simple method and post their results here. I hope you all find the success that I did.


307073
Larrys post has a few pictures of the BRC fuel injected BRC throttle bodies. More of BRC can be seen here:- http://brceng.com/brc-motorsports/

Video clip of a Inlet Port injected 15,000rpm 2T in action on the dyno.


Here are BRC EFI 125 engine videos


https://www.youtube.com/watch?v=8AWlJN4QMws


And photos of power curve and inlet

306947306948

[TZ350]

307219307220307221

Well tonight's effort was a total bust, the two injectors send out such a cloud that it wets out on the bellmouth and dribbles down into the plenum which totally negates the reason for having injectors in the first place. Ie to stop fuel pooling in the plenum.

I can see the advantage of having the injectors behind the throttle slide like they have on the BRC engine. Gave up for the night after the EFI filled the crankcase with raw fuel.

Neels sent me some very informative links.

http://www.sandia.gov/ecn/gaso<wbr>lineSprayCombustion.php (http://www.sandia.gov/ecn/gasolineSprayCombustion.php)

http://www.cmt.upv.es/ECN.aspx

Neels also suggested I take a closer look at what happens at an injector, things like the "liquid length" and atomization and finally evaporation. Also the effect of impinging on a wall at what stage of the plume development.

[TZ350]

Ok so I have starting to work it out.

307244

It was a bit hard but finally ... Success .....

I have been struggling with detto and running out of injection time trying to squirt in enough fuel to stop it.

In the end, the issue was all about the piston, which was (only just) tapping the head, not a big problem and I was to lazy to fix it, well tonight I did and the deto has disappeared.

307242

I shifted the injectors back to the transfer ports and now with a bit of decent squish clearance the Beast rev's to 12,500rpm plus with injection time to spare.

307245

So transfer port injection is a realistic option.

Initially I thought 9,000rpm was going to be the limit for transfer port injection but the Beast is now running to well past 12,000 rpm with the original transfer port injection setup.

307243

The injectors swap over at about 7k rpm and the two main injectors still have some injection time left at 12,800 rpm and so it looks like it could go to 13 easy enough.

Ok so now that it works, its time to tune it properly and see if we can better the old carb setup.

[TZ350]

307334

Alpha-N maps need to be smooth without any peaks or severe troughs between cell steps.

Ecotrons has a function where you can export a map to an Excel spread sheet and use the charting function to help smooth the map data.

307335 307336

Raw data and the chart showing how rough the data is and the engine ran just as roughly.

307337 307333

Smoothed data and chart.

No Idea if I have done this right, will get to find out tomorrow, hopefully .... :D

[TZ350]

Ok, I have found the section in the Ecotrons manual where it talks about tuning for the throttle blip.

307775

By default it does not work above 3,000rpm, but I can set it higher to suit my engine.

307776

From a quick read, the amount of enriching is tied to the predicted load increase as the throttle is opened. I guess its like a smart accelerator pump.

307777

You can determine the "Load" from the recorded data.

307778

And adjust the map, it looks like a bit of trial and error is required to get it right.

307783

There are other adjustments in the advanced calibration file for tuning for the rate of change in the throttle opening (TPS).

All I need to do now is learn how to use it.

[FastFred]

Posted TeeZee's work over here to keep all the EFI stuff in one place for future reference. You never know, but a EFI Turbo 2T with CVT transmission may be a future possibility.


:doh: I think I have shot myself in the foot again.

After the poor showing at Taumarunui where the bike would not come back on the throttle I thought I had better run it up on the dyno with the Ecotrons Procal tuning program displaying the Gauge monitoring screen in the hope of seeing what was going on.

The bike would start and trickle out onto the track easily enough and it would fly like a cut cat when it was shown a bit of stick. But it had two real bad faults, at about 8,000 rpm it would jump around like a demented kangaroo and when it was shut off at high rpm it would not come back on the throttle until the rpm had dropped under 7,000 rpm or so.

I thought it may be to rich/lean at lower throttle settings on over run at high rpm or it needed some adjustment to the throttle blip virtual fuel pump. But no amount of Map fiddling improved things.

Sorry about the jerky video but that is the bike shaking me around as I was recording the gauges. Its not dangerous to run a bike up full tit on the dyno by yourself with one hand while trying to record video with the other - yeer right its not dangerous.

Top left gauge is rpm and it tops out close to 13,000. Top right is the TPS and the two gages on the bottom right are for the injectors. Injector 1 to the left, Injector 2 to the right.

<iframe width="420" height="315" src="//www.youtube.com/embed/tXP6aUKbzcE" frameborder="0" allowfullscreen=""></iframe>

You can see injector 1 increasing in pulse width until it switches over to injector 2 at about 8,000 rpm, just where it starts to jump about. Then Injector two stays at 1.7ms right up to 13,000 ish rpm.

Close the throttle and injector 2 stays at 1.7ms until the rpm drops back below 7,000rpm and the system switches back to the smaller injector 1 at which point the engine will respond to the throttle again.

On over run above the changeover point the engine won't respond to small and medium throttle openings but at higher rpm it will jump back into life when given full throttle.

Previously I had been wanting to get as much fuel in as possible in the shortest amount of time and I had made injector 2 as large as possible and injector 1 was much smaller and only for starting and off pipe running below 8,000 rpm. The smaller the injector the more adjustable it is with the fuel map.

Both injectors have a minimum open time of 1.7ms and what I think is happening is that the big injector is too big and even at its minimum open time it drowns the motor at anything less than near full throttle.

And the jerking at 8,000 rpm is the EFI being confused about whether to use the injector that is to small or the injector that is to big.

I think Injector 2 needs to be smaller so it gets held open over a greater range of time from say 1.7ms at small throttle openings and high rpm to 3.5ms for full throttle at high rpm.

At the moment the EFI works well with injector 1 but it has no adjustment with injector 2, its all or nothing, actually injector two is virtually full on all the time above 8,000 rpm because it can't be run any slower than 1.7ms it needs more adjustment and we can only get that by going to a smaller injector because a smaller injector would need to be held open for longer than the minimum 1.7ms.

To get the greatest range of adjustment out of a fuel injector you need one that is only just big enough to do the job. I think I have been running one that is way too big for the job and even on minimum open time it is drowning the motor on overrun.

Instead of thinking big injector to get loads in quickly I think to get best throttle response I need to think smallest injector possible that is only just big enough to do the job at max fuel demand (max torque).

Tomorrow I will swap out the big injector 2 for a smaller one and see how that goes, here is hoping .... :)


308248

Ok after months in the wilderness I finally figured it out. And I was right about needing smaller injectors.

So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really .... :facepalm:

<iframe width="420" height="315" src="//www.youtube.com/embed/0lMT2GLtKsg" frameborder="0" allowfullscreen=""></iframe>

Now that I have smaller injectors fitted, on the bottom right gauge you can see the number 2 injection pulse width increasing and decreasing and it is coming back onto the throttle much better now that the EMS has some pulse width range to play with.

Not perfect yet but very very promising.

[TZ350]

Further Progress on the EFI thing ......



308248

Ok after months in the wilderness I finally figured it out. I was right about needing smaller injectors.

So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really .... :facepalm:

<iframe width="420" height="315" src="http://www.youtube.com/embed/0lMT2GLtKsg" frameborder="0" allowfullscreen=""></iframe>

Now that I have smaller injectors fitted, on the bottom right gauge you can see the number 2 injection pulse width increasing and decreasing and it is coming back onto the throttle much better now that the EMS has some pulse width range to play with.

Not perfect yet but very very promising.


308315

Making progress with mapping the fuel injection.

Did a series of runs at different throttle openings 100-90-80-70% etc and it fell apart at 40%.

I will have to sit down now and look at the recorded run data to see why, it may just be to rich or something else, like the injectors are still to big or not crossing over nicely at 8-9,000 rpm.


Injectors turned up from Ecotrons today, four days from date of order and two of them were weekend days, pretty good service in my books.

308623

I fitted a smaller injector and did a bunch of runs at different throttle settings. Interesting that the 60, 50 and 40% runs carry on out to close to 13,000 rpm.

308625

Blue line is the TPS. 100-90-80-70-60-50-40% throttle settings. It is certainly throttling and coming back onto the power much better. I will have to analyse the data to see if I can use an even smaller injector.

308624

Just by changing the central injector (and the injector size in the EFI software) I got the Blue line, I am not sure what that means as by rights, it was the same Alpha-N map so I was expecting the curves to be the same..... :scratch:


The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.

308855308856

I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between adjacent cells.

That means I can straight line it between say idle and where the fuel demand just starts picking up around 7,000 rpm. And once again use a straight line after peak torque where the fuel demand is relatively steady again.

The straight line does not have to be horizontal, it can tip up or down, its just a line between two points on the map that may be several thousand rpm apart but covers an area of relatively similar fuel demand.

By straight lining where I can, I now have spare rpm break points to use to smooth out the map where the fuel demand is rapidly increasing with increasing torque.

308853308854

From left to right on the model, the first cell covers 4,500 rpm the next 1,500 rpm and the next only 250 rpm but the steps between the cells are relatively the same, ie a smoother map. Anyway I hope this is what they meant.

308859

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

308857

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.


Yep, just like a large house party with interesting people.

308890

The EFI is going better than ever but :doh: the evening ended in a woopsie .....

308889

I was able to do several really good all gear runs with the bike coming back onto the throttle very nicely.

But my dreams of being the first persion to run an EFI 2T in a real F4 race on Sunday vanished when I felt the familiar overrun death shudder,

308891

Getting pretty hot, interesting stain at the top of the combustion chamber where it looks like the transfer streams sweep up into the head.

308888

Very dry in the bore and scratches that look like evidence of the ring ends butting up from over heating and the ring scraping the bore clean. Know more tomorrow when I get the cylinder off. It will be interesting to see how much oil there is in the crank case.


308969308970

Bit of quick work with a file and a light hone and everything is all good, even re used the piston ring, 2T's are so easy to work on

308968

Dyno runs from from 100 to 20%, looks OK so hopefully back on for Sunday.


Not sure about the ring gap now, looked good when I took it apart, I think you are probably right about the lean seize as it was definitely getting no fuel at closed throttle.
There is a software switch in Ecotrons where you can turn the fuel off on over run..... and I had to try it just to see what it did, as you do.:Oops:


You were on the money, I have been dialing in more fuel, heaps more fuel in the area of the Map that if it was a carb it would be the pilot and slide plus the very first bit of the needle.

Comes back on the throttle much better now, hopefully get to ride it tomorrow.


No, because it ran very well every where with 50% plus TPS. It was easy to get the EFI running in the "main jet" area. But tuning the lower parts of the Map is taking a bit of patience.

It would rev out real hard, shut the throttle and it would not light up again until the revs had dropped below 8 or the throttle was opened past 50%.

I had no idea what a Map should look like or if it was rich or lean until I put the O2 sensor back on it.

Been taking lots of dyno runs at part throttle and comparing them as I make changes to the Map.


Carburetors are great because of their analog ability to change the fuel delivery with changes in air flow at the same throttle setting.

EFI, well EFI is not forgiving at all.

309236 16 Alpha-N map lines with most of them concentrated in the upper power area of the graph.

Back to the EFI thing. The Ecotrons Alpha-N map has 16 rows to work with and I had concentrated them in the area where the power is, as you do. Well that turns out to be a mistake because there is not much difference in fuel demand per cycle between 100% throttle and 90 or 80 or even 70 at max power and virtual no difference at all above 40% in the 3 to 6000 rpm range.

The big jumps were between the lower throttle settings where there was not much excitement happening, well the mistake is that the CPU has a hard time bridging the big gaps below 40% especially when it is also trying to swap between low and high injectors at the same time.

309235 16 Alpha-N map lines more evenly spread so as to not have any big jumps between them.

Under 35% throttle is pretty unexciting power wise but on the track its a big deal as far as on track drive-ability is concerned. So for the next attempt I am going to use more Map lines in the lower area where things are changing rapidly with throttle position and less in the upper area where things are not changing so much, the power at 80% throttle is not very much different to 100%.

As it turns out, it was a mistake to concentrate my map in the power area, but I guess I will forgive myself..... :laugh:

[bigbadbob]

Hi guys and thanks for the info on ecotrons.
I'm playing around with an ecotrons 250 ninja ecu on my citroen 2cv engine trike and found a lot of usefull info here.
My setup is -
2 cyl 602cc boxer engine, 1 bmw 43mm throttle body with 1 injector. intake manifold splits from the throttle body to each cylinder.
Trigger is from a zephyr 550, four pulses per rev, one long, three short, like the ninja 250 but going clockwise.
As someone mentioned, when bench testing, the injectors appear to fire together in sync. so as long as the ecu will handle a map pulse every revolution then it "should" work. I might have to tell the software it's a single cylinder 301cc 2 stroke.
Great playing with this stuff.

Keep it sunny side up. :-)
Bob in Scotland.

[TZ350]

Hi Bob, glad to hear about your project, :niceone: can you post some photos? they would be interesting to look at. PS you may need to have made a few posts before you can post pictures. Anyway I would love to hear how your project progresses.

[bigbadbob]

Thanks for your interest TZ350.
I'll see if i can post some pics from photobucket........

http://i88.photobucket.com/albums/k180/bigbadbob76/ALIM0498_zps3c4b9b2d.jpg

http://i88.photobucket.com/albums/k180/bigbadbob76/Lpic0501.jpg

I had the setup running on the bench last night with the trigger wheel mounted in the lathe and scoped the outputs, only firing one injector and only once per rev, i need it to fire twice per rev but i didnt have any vacuum on the map sensor so that might sort it.
I'm turning up a flange to mount the trigger wheel on the tapered crankshaft, pics will explain it all when i get them up.

[bigbadbob]

Woohoo... that worked, so here's the bmw f650 throttle body that's been turned down to fit in a 955i inlet rubber and mounted on an insulated plate.

http://i88.photobucket.com/albums/k180/bigbadbob76/IMG_0169_zpsyqdrg9wz.jpg


and here's the end of the crankshaft, there's a fan that mounts on the tapered end but there's planty of room for a trigger wheel behind the fan.

http://i88.photobucket.com/albums/k180/bigbadbob76/5E7F9B74-31FF-4117-8FB7-3B5E09BB33B1_zpspzchzxaz.jpg


here's the aircraft aluminium flange i turned up,


http://i88.photobucket.com/albums/k180/bigbadbob76/85BDFE7B-7BFC-4F12-9E32-D7D6D6CB32DD_zpsslhez7wj.jpg

[speedpro]

So, flat twin, 180 degree crank, ignition triggers on the camshaft so assume the cylinders fire alternate revolutions or 360 degrees apart.

If you are using only one injector you will need to fire it every revolution as you have said. I'm assuming from what you have said that you are making your own trigger disc to go on the end of the crank.

If you make a trigger wheel with 6 short teeth and 2 long teeth in a symmetrical pattern - 3,1,3,1, the ECU will think the crank has done 2 revolutions when in fact it has only done one. If you have a MAP fluctuation "every" revolution instead of the Kawasaki's one, the ECU should fire injector one on the 2nd revolution as well. It should be fine to leave injector 2 disconnected but maybe a load wouldn't hurt.

The Ecotrons system uses the MAP to determine which cylinder is firing, instead of using a camshaft mounted "home" trigger.

Since you are doing fabrication I was wondering why you didn't use the Kawasaki/Ecotrons throttle body and just make a trigger wheel to match the required timing. The throttle body flows enough for the engine especially with the volume of the manifold acting as a plenum.

[bigbadbob]

Thanks for sharing your knowledge Speedpro. :2thumbsup great stuff.

Yes, 180* crank firing every 360*

I made up this trigger wheel-

http://i88.photobucket.com/albums/k180/bigbadbob76/DB0209AD-3529-4078-89C9-B263BBD7308C_zpsijyrjqyx.jpg

and spun it over on the starter with no fuel and ignition unplugged.

I stuck an led/resistor accross the injector plug in place of the injector so i can see when it squirts.

with revs per cycle set to 1 in advanced calibrations, N_Cyl set to 1 and 301cc.

it's Squirting on inj 1 only (thats fine) every 2 revolutions. (thats not. haha)
Unplugging the pickup makes it squirt every revolution. (on the map pulses).

This ties in with what you say about an 8 tooth wheel. :msn-wink:
not sure what rpm it will compute from that but will see what i can fabricate.

The trigger wheel has to be quite small (60mm) to clear the electronic ignition that sits where the points used to be.
My other option would be to mount triggers on the flywheel.

I didn't use kwak/ecotrons throttle body as i got the ecu 2nd hand without T.B. and f650 one is the same area as the 2cv twin choke carb.
Getting the plug and play kit from ecotrons was just too pricey to be worth it, mainly due to inport taxes and postage.

[speedpro]

Are you sure injector #1 is firing "every" crank revolution? You have the trigger on the cam so it is running at 1/2 speed or only once per complete 4-stroke cycle. When mounted on the crank it rotates twice for every complete cycle and relies on the MAP sensor to determine which cylinder to inject and ignite and the crank trigger precisely marks crank position on any particular revolution. My suggestion of 2X the teeth on the trigger wheel was thinking the trigger wheel was on the crankshaft and was just a way of tricking the ECU into thinking that the crankshaft had actually made 2 revolutions and it was now time to fire #1 injector again.

There is no need to be concerned about what revs the ECU thinks the engine is doing. You can reconfigure the rev points in each table so all you need to do is edit the range of revs to suit what the ECU "thinks" is happening. You want a number of rev points to define the map so you get some accuracy. As you are riding on the road you could tune it with a Lambda sensor. It will have to be a wideband sensor as it is likely to be off by quite a bit at the start.

You will have to define the cylinder capacity so that the values you enter into the maps fall within a valid range. Shouldn't be too hard on a low revving low tune engine like the 2CV. The map values will also depend on your injector size.

[bigbadbob]

Thanks again Speedpro.
The EFI trigger is on the crank as you suggest.
In the pics the ignition trigger is on the camshaft below the crankshaft, it has 2 magnets so ignition fires twice per camshaft rev, (wasted spark) but I'm not using that to trigger efi. keeping the ignition and efi separate at least for now.
I see what you mean about rpm doesn't matter, I can change the tables to suit. :2thumbsup

I have VE etc maps from a fella in Italy who has done this before with a 2cv using slightly different ecotrons ecu. So I have a base table for the engine to get me started, might need a wee tweak or two. :-)


edit: just out of curiosity i set cyl num to 2, both injectors now firing, :-) 180* apart and once every other rev as per the ninja 250.
If I unplug the trigger, it fires both in synch, every rev, in time with the map pulses. Don't think i can run it without the trigger tho.
Will see what happens with an 8 tooth trigger. looks like that's the answer. cheers Speedpro.

edit2: just tried trigger wheel with 4 short teeth. works the same as 1 long, 3 short, and doesn't report a ckp error.
so i guess it doesn't care about tooth length as it gets it's synch from the map pulse. 8 short teeth will do. ;-)

[bigbadbob]

8 tooth trigger doing the trick. :not:


http://i88.photobucket.com/albums/k180/bigbadbob76/E557297F-5778-4D3F-8C1B-B22C249BCFBF_zps5q7f4zxd.jpg

Squirting every rev. need to do some plumbing and wiring now and see if she'll start.
Then i can play with phase angle, RPM etc settings to get her running smooth.


http://i88.photobucket.com/albums/k180/bigbadbob76/83BAD1CB-8086-4394-AA53-7B26358A1F18_zps9zptjpiz.jpg

[bigbadbob]

She runs !!!!!!!! :done:

idles, revs, survives throttle blips and doesn't die when you slam the throttle shut.
seems to be reading the RPM correctly too.
reckon she's a bit on the rich side, judging by the plugs, but i'll play with that another day.
today I celebrate.

[speedpro]

Excellent. video next . . .

[TZ350]

She runs !!!!!!!! :done:

idles, revs, survives throttle blips and doesn't die when you slam the throttle shut.
seems to be reading the RPM correctly too.
reckon she's a bit on the rich side, judging by the plugs, but i'll play with that another day.
today I celebrate.

That is great, well done...... :drinknsin

[bigbadbob]

Thanks guys.
Now I have to re-build the machine. she's in bits just now.
I'll get back to you with a video in about 6 months. :laugh:
Lots of work to do yet but the guy in Italy say his runs best when tuned a bit on the rich side too so maybe I don't have to tune too much.

As a matter of interest, I reckon it's using the MAP sensor to measure RPM. based on my "one rev per cycle" setting.
Also at one point last night, the trigger wheel came loose when I whacked the throttle open, she fluffed and died. however when I re-started without the trigger wheel she idled ok but as soon as I opened the throttle she fluffed and died again.
proves I can't run without the trigger wheel.

This is a good learning experience.

[BASS-TREBLE]

I have to say I haven't read the whole thread word by word but I have had issues with a microsquirt (I know it's different) in the past with having long teeth like you do. Mainly that a long tooth(longer than the sensor) can cause unpredictable timing as described about 1/3 down this page with the diagrams http://www.useasydocs.com/theory/pickups.htm

No idea if it will cause issues for you but just a possible heads up. Keep up the work, will be interesting to watch.


8 tooth trigger doing the trick. :not:


http://i88.photobucket.com/albums/k180/bigbadbob76/E557297F-5778-4D3F-8C1B-B22C249BCFBF_zps5q7f4zxd.jpg

Squirting every rev. need to do some plumbing and wiring now and see if she'll start.
Then i can play with phase angle, RPM etc settings to get her running smooth.


http://i88.photobucket.com/albums/k180/bigbadbob76/83BAD1CB-8086-4394-AA53-7B26358A1F18_zps9zptjpiz.jpg

[Drew]

Thanks guys.
Now I have to re-build the machine. she's in bits just now.
I'll get back to you with a video in about 6 months. :laugh:
Lots of work to do yet but the guy in Italy say his runs best when tuned a bit on the rich side too so maybe I don't have to tune too much.

As a matter of interest, I reckon it's using the MAP sensor to measure RPM. based on my "one rev per cycle" setting.
Also at one point last night, the trigger wheel came loose when I whacked the throttle open, she fluffed and died. however when I re-started without the trigger wheel she idled ok but as soon as I opened the throttle she fluffed and died again.
proves I can't run without the trigger wheel.

This is a good learning experience.
Does MAP not stand for Mass Absolute Pressure with Exotrons? I can't understand how it would figure out it's revs from that.

[speedpro]

Does MAP not stand for Mass Absolute Pressure with Exotrons? I can't understand how it would figure out it's revs from that.

The value of the MAP sensor fluctuates with every revolution. That being the case it could easily be used to determine the speed of rotation. It most definitely is used to determine which cylinder is where in the 4-stroke cycle on the Kawasaki 250 installations but I'm not sure if it's used to monitor engine speed. Bob's install could be used to determine if it does. If the ECU thinks the engine is doing twice the speed it actually is then the trigger disc is used, if the engine speed is correct in Ecotrons then the MAP sensor is being used.

[bigbadbob]

Thanks for the heads-up and the link Bass-Treble. Good food for thought. :cool:
As far as I can tell, the ecotrons ecu only looks at the rising edge of the positive going pulse at the start of the tooth and ignores the negative going one at the end of the tooth. also I "think" it uses a 2 volt threshold rather than the zero crossing shown in your link. don't quote me on that though. As you say, microsquirt is different.
The ninja 250 CDI uses a long tooth to determine which cylinder to fire for ignition and Ecotrons copes with that, and even the "short" teeth on the Ninja are a good bit longer than the Coil head so it looks like i'll be ok.

DREW- you got me thinking about the RPM count. :rockon:
On the ninja... the ecu expects to see 2 revs per cycle, 4 trigger pulses per rev = 8 pulses per cycle and 1 MAP pulse per cycle. (it only reads cyl 1 MAP)
I have set it to expect 1 rev per cycle and using an 8 tooth wheel gives 8 pulses per rev = 8 pulses per cycle and 1 MAP pulse per cycle (I'm reading both cylinders)
If it counts cycles using MAP, and RPM using trigger, then this will compute correct RPM. :woohoo:

I hope this install can help us understand more about the Ecotrons ECU. If anyone has any checks they want me to do, feel free to ask.

I'm going to play with the angle BTDC when the injector fires but I have a long inlet manifold so it might not make much difference in my case.
I think it fires injector 1 on the 6th trigger pulse after each MAP pulse, would need a 3 channel digital scope to check that though.
MAP pulse voltage drop threshold for a valid pulse can be set in advanced cal. ;-)

Speedpro- can you tell me how to link one o2 sensor to both injectors in software and also how to disable feedback but still read o2?
I probably won't need to, but knowledge is king! one of these days I'd like to try using 2 injectors, 1 per cylinder, but don't think that's going to be do-able with the ninja ECU.

[bigbadbob]

Well... I bust an oil cooler pipe and had to get a new cooler so the project has been on hold...
New cooler now fitted so we're back on track.
Something's up with the O2 sensor though as it's reading ok for a few seconds then drops to 14mv once it warms up.
I have a spare sensor but want to be sure i'm not flooding it with unburned fuel before i replace it.


http://i88.photobucket.com/albums/k180/bigbadbob76/trike%20run%20graph_zpsnyortwmq.jpg

[TZ350]

Posted this because someone asked me about the jerky response they are getting now that they are running split injection. Ie they are using a small injector for slow running and a large injector for power. I think the issue is in the size of the step on the map at the point where the ECU changes from the small injector to the larger one.

The Ecotrons Alpha-N map is not a fuel map but a map of predicted changes in engine load (torque) with respect to TPS and RPM.

315987 315978 315990

It is like a stair case and to keep the Load steps even, it is possible to cluster the rpm steps around the area of rapid changes in Load (torque). And on my dyno graph that is 7,500 to 9,500 rpm (yellow line). Above that the power goes up with rpm but the change in Load is a lot flatter. So you can have quite wide rpm steps below and above where the engine comes onto the pipe and cluster the rpm steps where the Load (torque (yellow line)) curve climbs rapidly so as to have even predicted Load steps across the complete rpm range from 3,000 to 13,000.

Ie on my map the first rpm point is at 3K rpm, the second is 6k the third is 7k then 7.5k, 7.75k, 8k, 8.5k, 9k and rpm step 9 is 9.5k step 10 is 11k then 12.250 and finally 13,250 rpm. So the spread of rpm points is chosen to get even changes in the Load steps.

My TPS steps are 0, 10, 12, 15, 18, 20, 26, 31, 36, 41, 46, 51, 61, 71, 85, 98. there is much greater changes in air flow at low TPS than there is above 70%. If you look at the dyno graph everything above 70% has pretty much the same power output.

What I think happens when split injection does not work properly and jerks all around the place is that when the small injector gets to a load cell step that is to big and would max it out the ECU swaps to the big injector which squirts to much fuel for the rpm (because the min on time for the big injector flows to much fuel) and the rpm drops back below the small injectors last effective load cell and the air/fuel clears and the rpm slams backup and the cycle violently repeats itself. Now a smaller big injector might help but a disparate size in the load steps can be the real problem.

This will not be confined to a set rpm position on the map but a patch of Load cells where the effective differences in predicted Load is to great. And I expect the ECU's hysteresis between injectors will play a part here too.

The trick is to group the RPM columns and TPS rows in such a way that the changes between adjacent Load cells in any direction are much the same.

[2005bully]

I am looking to install the ecotrons unit on a single 250cc 2 stroke. Would like to incorporate the control of ignition timing with the EFI. The ecotrons web site shows the compatible cdi system they offer has an upper rpm limit of 8,000 rpm's. Is that correct? If so has anyone found a way around the low rpm limit?

[TZ350]

I am looking to install the ecotrons unit on a single 250cc 2 stroke. Would like to incorporate the control of ignition timing with the EFI. The ecotrons web site shows the compatible cdi system they offer has an upper rpm limit of 8,000 rpm's. Is that correct? If so has anyone found a way around the low rpm limit?

I have never tried the Ecotrons CDI system. But I suspect the 8,000 2T limitation is not in the software but in the aftermarket CDI box. The Ecotrons CDI box looks like an un restricted 4T scooter item where 16,000 4T rpm is pretty good.

The Ecotrons CDI is one of the 12V dc variety where the CDI internally develops its own high voltage just like my Ignitec does.

316003

There is also an AC scooter CDI box (looks the same) where the high voltage is generated externally by some HV windings on the stator and triggered by a pulse coil. If you have a HV winding on your stator you might be able to try one of those and trigger it with the Ecotrons CDI trigger system.

Maybe using the Ecotrons CDI trigger signal for a mapped digital output and a purpose built CDI box might work.

I use the Ignitec 12VDC-CDI and run both the Ecotrons EFI system and the Ignitec CDI in parallel off the original engine ignition trigger and TPS.

[2005bully]

I have never tried the Ecotrons CDI system. But I suspect the 8,000 2T limitation is not in the software but in the aftermarket CDI box. The Ecotrons CDI box looks like an un restricted 4T scooter item where 16,000 4T rpm is pretty good.

The Ecotrons CDI is one of the 12V dc variety where the CDI internally develops its own high voltage just like my Ignitec does.

316003

There is also an AC scooter CDI box (looks the same) where the high voltage is generated externally by some HV windings on the stator and triggered by a pulse coil. If you have a HV winding on your stator you might be able to try one of those and trigger it with the Ecotrons CDI trigger system.

Maybe using the Ecotrons CDI trigger signal for a mapped digital output and a purpose built CDI box might work.

I use the Ignitec 12VDC-CDI and run both the Ecotrons EFI system and the Ignitec CDI in parallel off the original engine ignition trigger and TPS.



I have been using the HPI digital ignition. For testing my preference is to use a single crankshaft trigger, with a constant loss battery powering both the ignition and EFI. But for right now I will retain the HPI ignition. The HPI stator does not appear to have separate trigger to tap into. I realize that if the input is received from a point after the CDI box the EFI input will follow the ignition timing curve. But can the primary input wire going to the coil be used? I did e-mail Ecotrons asking if there was a way to work around their ignitions low rpm limit.

[TZ350]

Just countersink the back of the plate and have fully threaded csk cap bolts sticking out.

I think you are stuck with having to make a proper trigger for the EFI. Maybe something like Wobs cap screw idea.

[bigbadbob]

Don't suppose this helps but the ecotrons Ninja 250 ECU I've re-puposed has a built in CDI which drives coils directly and revs to 15k+, maybe you could re-pupose one for your use. it takes it's trigger from the pickup coil.

[Lynxdragon]

could always go to megasquirt. I've played with a few and were very happy.


Sent from my iPhone using Tapatalk

[speedpro]

[QUOTE=bigbadbob;1130908266]Don't suppose this helps but the ecotrons Ninja 250 ECU I've re-puposed has a built in CDI which drives coils directly and revs to 15k+, QUOTE]

15K+ is what they say. In actual fact you can't configure the maps above 16K as this is the maximum value able to be entered into the tables. If indeed the system will allow revs over that value you are stuck with whatever parameters you have configured at 16K. I haven't been able to rev my engine over 15-16K but that may be due to tuning which is why I have been trying to make a brake dyno, for testing.

The ignition side is good with a big strong spark. I haven't had any problems with it yet and haven't suffered with loaded plugs despite having some odd tuning at times with starting from scratch.

Ecotrons have been quite helpful with alterations I have asked for to the software. I am just a bit annoyed with the answers I got prior to buying the system about the ability to rev and to handle boost. They probably never thought the engine was ever going to run so it wouldn't be a problem.

[TZ350]

could always go to megasquirt. I've played with a few and were very happy.

Yep Megasquirt would probably be good but this is a, how to get the best out of your Ecotrons thread. :niceone:

[Drew]

Yep Megasquirt would probably be good but this is a, how to get the best out of your Ecotrons thread. :niceone:

What if the best that can be got, is trading it for a Megasquirt?

[Lynxdragon]

I would agree, ecotrons is great to use the injectors, tps and oxy sensor from, but if you want higher rpm your probably going to have to bite it and use a megasquirt.


Sent from my iPhone using Tapatalk

[TZ350]

What if the best that can be got, is trading it for a Megasquirt?

...... :bleh: probably true. LOL


I would agree, ecotrons is great to use the injectors, tps and oxy sensor from, but if you want higher rpm you're probably going to have to bite it and use a megasquirt.


Yes the injectors and other components are great.

316307

This is a dyno graph of my Ecotrons 125cc 2T setup at different throttle positions. RPM is not an issue on the fuel side for me and 2T 12k rpm suggests that 4T 24k rpm is mechanically possible by Ecotrons.

But I don't have a lot of experience with Ecotrons ignition side as I continued to use my Ignitec system for lighting the fire. I suspect any issues with the Ecotrons 2T ignition side is in the CDI black box rather than the software.

[Lynxdragon]

slap another degree of advance on it. haha.


Sent from my iPhone using Tapatalk

[bigbadbob]

There is a max RPM calibration setting in procal, I assume you've wound that up :cool:


They probably never thought the engine was ever going to run so it wouldn't be a problem.

lol, mine too.




Excellent. video next . . .


Here you go speedpro-

http://i88.photobucket.com/albums/k180/bigbadbob76/th_9347AEBA-94DF-413C-90C4-6A68B2FF582E_zpsu3nks91j.mp4 (http://i88.photobucket.com/albums/k180/bigbadbob76/9347AEBA-94DF-413C-90C4-6A68B2FF582E_zpsu3nks91j.mp4)

not the best quality, done on my phone, but you get the idea.

[speedpro]

Running sweet, response is good.

[bigbadbob]

Speedpro- have you seen this-

www.dtic.mil/dtic/tr/fulltext/u2/a558274.pdf

Worth a read if you can wade through the bits that are irrelevent to us.

[2005bully]

I went ahead and got the CDI parts that Ecotrons recommended coming from them. Ecotrons tells me that the HPI ignition that I currently am using does not have a useable pick-up and suggested to instead use a constant loss battery with a Hall sensor. But today I got to looking on line and saw most of the oriental scooters have external flywheels, 12volt output for charging, and separate trigger coils located on the outside of the flywheel. Be sides that they are cheap. I do not know what the life of them would be, but for testing it might be just as easy to adapt one of them as it would be to make all the attachments for an independent trigger, plus I would have the alternator already built in. If the quality is not up to the task I would think that better replacements are available. I saw in past posts where the 6 volt versions could be re-wound to produce 12 volts. But since I'm going to purchase new.... does any one have a suggestion of a common oriental model that would best fit the application???? The motor is a 250cc running methanol, and will be use on a fixed gear race kart. As long as the unit will physically fit in the space.... adaptor plates or changing the flywheel tapers etc. is not a problem... Kermit Buller

316397

[TZ350]

Hi Kermit, I think the Scooter alternators are quite good, fairly big and heavy for a 125 but Ok for a 250 thats not running past 9k rpm. There are units that are generators only and others that have high voltage CDI capacitor charging coils as well as generator coils.

[2005bully]

Hi Kermit, I think the Scooter alternators are quite good, fairly big and heavy for a 125 but Ok for a 250 thats not running past 9k rpm. There are units that are generators only and others that have high voltage CDI capacitor charging coils as well as generator coils.

Thanks....

I'll pick out one that looks fairly common and get it coming.

[2005bully]

Hi Kermit, I think the Scooter alternators are quite good, fairly big and heavy for a 125 but Ok for a 250 thats not running past 9k rpm. There are units that are generators only and others that have high voltage CDI capacitor charging coils as well as generator coils.

I have a stator with flywheel coming for a GY6 engine. It is an 8 pole, 12v and has an external CDI pick-up coil. I already have various ignition coils, so I think I'm ok there. Will I be able to patch the signal from the trigger coil directly into the Ecotrons EFI box, and have an output going directly to the coil? Or do I need a "cdi" box in-between ?

Kermit Buller

[speedpro]

As you described on mine, no separate ignition box needed.

[2005bully]

As you described on mine, no separate ignition box needed.


I received the gy-6 ignition. You are right it is a little bulky, but performance wise the weight should be a plus in this application. While waiting to get the rest of the parts from eco-trons, spare time has been spent trying to learn the soft ware. So far it is quite confusing..... Not sure if its my poor chenglish, or some conceptual part of it has passed me by. I hope it makes more sense when the hard parts are in front of me.... Kermit Buller

[TZ350]

While waiting to get the rest of the parts from eco-trons, spare time has been spent trying to learn the soft ware. So far it is quite confusing..... Not sure if its my poor chenglish, or some conceptual part of it has passed me by. I hope it makes more sense when the hard parts are in front of me.... Kermit Buller

There are a number of posts earlier in the thread that may be a help.



The Ecotrons fuel injection system is my first experience with EFI.

http://i1290.photobucket.com/albums/b522/TZ350AB/Start ProCal/Bubbles-2_zpsb58f2623.jpg (http://s1290.photobucket.com/user/TZ350AB/media/Start ProCal/Bubbles-2_zpsb58f2623.jpg.html)

A guide to installing and using the Ecotrons electronic fuel injection ProCal tuning software based on the experiences of a complete newbee with no previous EFI experience.

Hopefully all this will be a help to anyone else trying to get their head around the ProCal file and directory structure.

I found the small engine Ecotrons EFI kit easy to put together as everything was labeled.

316799

[TZ350]

.

The biggest lesson I learned with EFI was to use the smallest injector possible.

The smaller the injector the more tun-able the result at low throttle settings. Because all injectors have a minimum on time a small injector can squirt less fuel than a larger one for the same minimum map setting. Ie a larger injector can have plenty of safety margin at maximum power but be to rich at low speed and can't be turned down any lower or leaner because of its minimum on time and as a result it floods the engine at low speed.

[BASS-TREBLE]

.

The biggest lesson I learned with EFI was to use the smallest injector possible.

The smaller the injector the more tun-able the result at low throttle settings. Because all injectors have a minimum on time a small injector can squirt less fuel than a larger one for the same minimum map setting. Ie a larger injector can have plenty of safety margin at maximum power but be to rich at low speed and can't be turned down any lower or leaner because of its minimum on time and as a result it floods the engine at low speed.

This hits the nail on the head and is also exactly why staged injection with multiple injectors is key for high HP engines while still maintaining low end drivability.
By letting small injectors control the low end and then adding the large injectors for up top HP you have the best of both worlds, except the need for two fuel rails etc :doh: which also explains why it is seen on most bikes these days.

[speedpro]

Been a while but made lots of progress in the last week. The little FZR is up and running well with the Ecotrons engine management and the turbo. I have been having a few problems, which may have been due to power supply problems though I am running a small lead acid battery and the FZR stock generator and reg/rec. I have added a large car battery beside the bike for dyno runs and modifying software.

Problems:
1 - my fuel pressure regulator partially failed causing a drop in fuel pressure and eventually no fuel pressure. With the slightly different engine and the progress I was making I just thought the need for bigger injectors and greater injector pulsewidths was how it was working out. It wasn't. Plenty of time wasted chasing problems related to this. My suggestion is that you should always monitor fuel pressure. A quick test to see if the regulator has the problem is simply to remove it and try blowing through it. We discovered Rob's spare had the same problem but it was still working but as per mine would have had reduced fuel pressure. The problem I had was caused by a little o-ring inside that had been damaged.
2 - The TPS indicator in Procal stops working unless you turn the throttle more than about half way open. I checked the TPS configuration, even measured the actual voltages and updated the parameters with the calculated values. The cure is simply to reflash the ECU. I've done nothing else and it's fixed the problem and I've done it more than once. I have loaded the last active ".cal" file as well and it stayed working.

I've gone back to the 80g injectors and even with the minimum injector time reduced to 1.4mS it is still rich at all small throttle openings and they can still supply the required fuel at 16,000rpm with only a 4mS, or so, pulsewidth, even with the turbo pushing the intake to 1bar, or 0lbs boost.

[speedpro]

Had the bike on my brake dyno this afternoon. The sole task was to run autotune and check results. First it was hard to start despite having the previous good tune loaded. Based on recent experience I flashed the ECU and loaded the exact same tune. The engine fired up first try afterwards. I still have no explanation for this, I just know that it is effective.

What I have discovered is that autotune has it's own VE & TPS tables stored in the ECU along with a record of which areas have been tuned. That record is in a table which has 20 throttle position columns and a range of engine speed rows. I have my system setup to use the VE table, which is load versus rpm, at anything less than 98% throttle. The record of successful autotune is therefore not totally relevant to how I am using the system. The record of successful autotuning for me would be better off being a table with a similar matrix to my VE table. Having said that it does work well. It is only the record of which areas have completed tuning that is a mismatch. The autotune VE table is updated over a larger area than is indicated by the tuning complete table. Flashing the ECU does not erase these tables. These tables are in no way able to be manually edited but they can be exported to a CSV file. From there it seems, I haven't done it and tried running the engine, you could copy the values to a VE table and run the system in 'manual tuned data" mode using that autotune data. If autotune is "on" you can alter the VE and TPS tables all you like and it will have no effect because the ECU is using the autotune versions of VE & TPS tables. The regular tables would only become effective if autotune was disabled AND you switched back to manual tune data.
What I have found is that the ECU is autotuning to richer than stoichiometric despite the Eco/Power mode switch being in the "0" or Eco position where it should be aiming for lambda = 1. My ALM gauge is trending towards 13.?:1 or slightly rich. I think this is due to a need to adjust a table which defines the output of the ALM to the ECU as being various values of lambda.
I haven't completely sorted clearing the tables and loading a new default, whether it loads the VE & TPS tables from the ECU or whether it loads a "default" set of tables from within the ECU. At some point a few days ago I ended up with autotune tables which were nothing I created. My system is supposed to be for a GPz250 so I think the "default" tables may be suitable as a start for one of them. I will sort that out.
When autotuning we were able to load the engine up at certain revs and load and hold it reasonably constant. Reading the TPS screen gauge and the MAP I could pick which cell would be tuned and filled with green. I could also tell which area of the autotune VE table would be altered. The autotune software varied a range of cells about the particular cell that was active. This made for a 3d chart that had no odd peaks or troughs. More time would see it looking pretty swoopy.

The dyno has not much inertia. I built it to use the brake so the bike is pretty much free revving in this video. Towards the end I loaded it to 1 bar manifold pressure at about 12,000rpm. It doesn't sound like it but you can see the gauges and also the tuned areas in the chart.

https://youtu.be/_5HMp6co4EA

[TZ350]

Great work ..... :clap:

[2005bully]

I received the gy-6 ignition. You are right it is a little bulky, but performance wise the weight should be a plus in this application. While waiting to get the rest of the parts from eco-trons, spare time has been spent trying to learn the soft ware. So far it is quite confusing..... Not sure if its my poor chenglish, or some conceptual part of it has passed me by. I hope it makes more sense when the hard parts are in front of me.... Kermit Buller

This project had involved fitting an Ectrons EFI on a yz-250 running methanol. I have all the parts in place, with the exception of a methanol fuel pump. After further study of all the calibrations involved. Then acknowledging my inexperience with EFI it seems more logical to start off with gasoline as the base fuel. So I am going to order injectors sized for petro. Will be back posting about this project at a later date.... Thanks to ALL!!!!!!

[Cheesy]

Had the bike on my brake dyno this afternoon. The sole task was to run autotune and check results. First it was hard to start despite having the previous good tune loaded. Based on recent experience I flashed the ECU and loaded the exact same tune. The engine fired up first try afterwards. I still have no explanation for this, I just know that it is effective.

What I have discovered is that autotune has it's own VE & TPS tables stored in the ECU along with a record of which areas have been tuned. That record is in a table which has 20 throttle position columns and a range of engine speed rows. I have my system setup to use the VE table, which is load versus rpm, at anything less than 98% throttle. The record of successful autotune is therefore not totally relevant to how I am using the system. The record of successful autotuning for me would be better off being a table with a similar matrix to my VE table. Having said that it does work well. It is only the record of which areas have completed tuning that is a mismatch. The autotune VE table is updated over a larger area than is indicated by the tuning complete table. Flashing the ECU does not erase these tables. These tables are in no way able to be manually edited but they can be exported to a CSV file. From there it seems, I haven't done it and tried running the engine, you could copy the values to a VE table and run the system in 'manual tuned data" mode using that autotune data. If autotune is "on" you can alter the VE and TPS tables all you like and it will have no effect because the ECU is using the autotune versions of VE & TPS tables. The regular tables would only become effective if autotune was disabled AND you switched back to manual tune data.
What I have found is that the ECU is autotuning to richer than stoichiometric despite the Eco/Power mode switch being in the "0" or Eco position where it should be aiming for lambda = 1. My ALM gauge is trending towards 13.?:1 or slightly rich. I think this is due to a need to adjust a table which defines the output of the ALM to the ECU as being various values of lambda.
I haven't completely sorted clearing the tables and loading a new default, whether it loads the VE & TPS tables from the ECU or whether it loads a "default" set of tables from within the ECU. At some point a few days ago I ended up with autotune tables which were nothing I created. My system is supposed to be for a GPz250 so I think the "default" tables may be suitable as a start for one of them. I will sort that out.
When autotuning we were able to load the engine up at certain revs and load and hold it reasonably constant. Reading the TPS screen gauge and the MAP I could pick which cell would be tuned and filled with green. I could also tell which area of the autotune VE table would be altered. The autotune software varied a range of cells about the particular cell that was active. This made for a 3d chart that had no odd peaks or troughs. More time would see it looking pretty swoopy.

The dyno has not much inertia. I built it to use the brake so the bike is pretty much free revving in this video. Towards the end I loaded it to 1 bar manifold pressure at about 12,000rpm. It doesn't sound like it but you can see the gauges and also the tuned areas in the chart.

https://youtu.be/_5HMp6co4EA

Unless you have an earthing issue shouldnt the ECU be using the same AFR as shown on your gauge? Can you display the AFR from the ECU on a laptop and compare it to the gauge? That said tuning to 13.xx may not be that far off the mark even for an economy setting. I have just put a wide band in my Megasquirted Range Rover it it likes to idle at 13:1.

I might have this wrong but are you saying that the ECU is auto tuning a load(MAP)-rpm VE table by using a Speed-TPS table and associated AFR table? If that is the case wont that lead to all sorts of problems when you throw the turbo in the mix? The system seems a bit strange in that it sounds like it wont let you edit the auto tune table and or run from that table with auto tune turned off.

[F5 Dave]

This project had involved fitting an Ectrons EFI on a yz-250 running methanol. I have all the parts in place, with the exception of a methanol fuel pump. After further study of all the calibrations involved. Then acknowledging my inexperience with EFI it seems more logical to start off with gasoline as the base fuel. So I am going to order injectors sized for petro. Will be back posting about this project at a later date.... Thanks to ALL!!!!!!
Presumably you have read up about the yz250 fletner did, but with a link.

[TZ350]

<iframe width="560" height="315" src="https://www.youtube.com/embed/ifSEql1X4R0" frameborder="0" allowfullscreen=""></iframe>

E85 fuel, fuel injected Kawasaki 350 BigHorn, I think there will be more info on the Foundry thread. They also fuel injected a late model YZ250 Yamaha. Both are running the bigger Ecotrons type fuel pumps. E85 and Methanol are much easier to get right with EFI than petrol because they can be run way over rich well clear of the lean danger zone.

Follow the post below to read about the BigHorn and YZ250 EFI projects



http://i854.photobucket.com/albums/ab102/GerbilGronk/Random%20Shots/IMG_8929_zpsccfc0f9d.jpg
http://i854.photobucket.com/albums/ab102/GerbilGronk/Random%20Shots/IMG_8928_zpsfe2f88c5.jpg

Took the EFI YZ250 to the Epic Events ride Taupo / Napier road yesterday, in the rain. Performed flawlessly though out the whole day. Tuned to give smooth broad power, best for these conditions. It's a lot of fun to ride, this is the first ever "Event" it's been to.

That is the Ecotrons E85 fuel pump you can see in the middle right of the picture.

[husaberg]

<iframe width="560" height="315" src="https://www.youtube.com/embed/ifSEql1X4R0" frameborder="0" allowfullscreen=""></iframe>

E85 fuel, fuel injected Kawasaki 350 BigHorn, I think there will be more info on the Foundry thread. They also fuel injected a late model YZ250 Yamaha. Both are running the bigger Ecotrons type fuel pumps. E85 and Methanol are much easier to get right with EFI than petrol because they can be run way over rich well clear of the lean danger zone.

Follow the post below to read about the BigHorn and YZ250 EFI projects



That is the Ecotrons fuel pump you can see in the middle right of the picture.

http://www.kiwibiker.co.nz/forums/showthread.php/158975-Yamaha-YZ-250-EFI
<iframe width="560" height="315" src="https://www.youtube.com/embed/1YG9ko8-Nwk" frameborder="0" allowfullscreen></iframe>

http://youtu.be/hOGZ5llowoU

[speedpro]

Unless you have an earthing issue shouldnt the ECU be using the same AFR as shown on your gauge? Can you display the AFR from the ECU on a laptop and compare it to the gauge? That said tuning to 13.xx may not be that far off the mark even for an economy setting. I have just put a wide band in my Megasquirted Range Rover it it likes to idle at 13:1.

I might have this wrong but are you saying that the ECU is auto tuning a load(MAP)-rpm VE table by using a Speed-TPS table and associated AFR table? If that is the case wont that lead to all sorts of problems when you throw the turbo in the mix? The system seems a bit strange in that it sounds like it wont let you edit the auto tune table and or run from that table with auto tune turned off.


The ALM supplies a voltage to the ECU which varies with the mixture . If the ECU thinks that 1v from the ALM is Lambda=1, and it receives 1v, then as far as it is concerned the fueling is at lambda=1 and autotuning is complete. The problem seems to be that 1v is NOT Lambda=1. I can see 1000mV on Procal but the ALM gauge says 13.?:1. I'm sure I've seen a table where these values can be adjusted but can't remember where.

Autotuning has 2 separate maps in the ECU that are the same configuration as the regular manually tuned maps. 1 - Volumetric Efficiency(VE) map. This map uses manifold pressure versus rpm and has VE values entered and 2 - a load map which uses TPS and RPM and has load values entered.

I have configured my system to use the VE map up to 98% throttle. As I have a turbocharger fitted the throttle position is not a good indicator of load. Manifold pressure however is a good indicator and varies with throttle position and turbo operation.

Not allowing the user to edit the autotune tables makes perfect sense. There are tables which can be manually edited if the users wishes and you can switch between them as desired.

I suggest that the way to use the autotune function is to let it run and update the values in the autotune tables. In my case it is only altering the VE table. This information can be exported to a "csv" file where the table data is in the same format - rows, columns, & values, as the manually edited table. I then import those values to the manually tuned VE table. The manually tuned and auto tuned tables are now identical. I can then make minor adjustments to say the low speed/load values to make the engine run sweet if needed. I would have to stop autotuning and switch to manual tuned date for the manually tuned VE table to be effective. For a road bike this would be sweet. You can have one map which is perfect for economy and emissions and with a flick of the Eco/Power switch ramp the fuel up to the "Driver Desired Lambda" which would be set to .8? for best power.

In autotune by default with the Eco/Power switch set to Eco it tunes for Lambda=1. If you switch to Power it tunes to the "Driver Desired Lambda". Apart from taking time to retune the maps for the different Lambda it defeats the whole purpose of autotuning. You could of course leave the switch in Power whilst autotuning and just have it auto tune to your desired Lambda value. A better option is to do what I have suggested above.

In manually tuned mode the ECU assumes that the VE & TPS tables are tuned for Lambda=1 or the ideal mixture. In Eco mode it uses the tables to determine the fuel to inject. When you switch to Power it simply adds a percentage of fuel as determined by the difference between Lambda=1 and the value of "Driver Desired Lambda". If you have the Narrow Band(NB) Lambda sensor and were using it for feedback in Eco mode, it is no longer used in Power mode as feedback is disabled. Power mode is open loop and relies on the VE & TPS tables being correct to then add a % to in order to obtain the desired lambda. NB lambda sensors only work at stoichiometric and their output only switches if the mixture is richer or leaner. It doesn't matter how much richer or leaner so they cannot be used to monitor how rich a mixture is, only that it is richer.

In my case autotune is creating an autotune table that has the engine running a bit rich. I have exported that autotune data and then imported the VE values into a manual tune map. In excel I can simply multiply each cell by about .9 to reduce the fuel calculated which should bring the Lambda back to 1 whilst maintaining the overall profile. Loaded and run, in manual tune mode and using the manual tuned maps, I should obtain Lambda=1 when running the engine. I have actually done this and it seems to work, though I have only run the bike in the garage without load so only monitored the very low or no load areas.

I have also determined that my ECU by default has a set of autotune VE & TPS tables in the ECU, probably for a GPz250. If I enable autotuning and select "reset to default data" it loads my manual tuned VE & TPS maps. If you have spent any time sorting out your own maps you should make sure your maps, and not some default maps, are loaded before starting the autotune process. There is something else going on in the ECU around these maps. Supposedly you can "flash" the ECU and the autotune maps are unaltered but mine has reverted back to the default maps a couple of times but I haven't sorted when that happens. Another good reason to export the data and then import it into manually tuned maps.

Regarding which maps can be used when autotune is off, you can select which maps the ECU uses, either the auto or manual tuned maps.

[Cheesy]

There is something up with your wideband by the sound of it then, 1V should be somewhere around 11:1 and stoich around 2.5-3 volts depending on the controller. Just as a note I wouldnt be tuning your motor to anywhere near 14.7, it will not like it and may even do damage under load. I take it that the auto tune adjusts the whole table to a single lambda? this is the target AFR table I started for my car a while ago, it kind of negates the need to switch between a power and economy table

http://i758.photobucket.com/albums/xx224/tododgy/Rover%20stuff/90e376e0-5f33-4963-a0fa-ac3d692049f8_zpsaopxcn06.png

[speedpro]

There is something up with your wideband by the sound of it then, 1V should be somewhere around 11:1 and stoich around 2.5-3 volts depending on the controller. Just as a note I wouldnt be tuning your motor to anywhere near 14.7, it will not like it and may even do damage under load. I take it that the auto tune adjusts the whole table to a single lambda? this is the target AFR table I started for my car a while ago, it kind of negates the need to switch between a power and economy table



You are absolutely right. My controller output is Lambda=2 - output=5v. Lambda=1 - 1.667v, Lambda=.9 - 1.33v, Lambda=.8 - 1.0v, Lambda=.7 - 0.667v, Lambda=.6 - 0.333v. In Eco mode the target lambda is 1.

Like I've suggested above though we can then export the autotune data, divide all values by, or only a certain few, by say .8, and save as the active VE map. OR, tune for Lambda=1 using autotune then again copy all the data to the active manual map. Then switch the Eco/Power switch to Power whereupon extra fuel is calculated on top of what is required for Lambda=1. Extra fuel is added to adjust the Lambda to whatever values are in the Drivers Desired Lambda table - see attached. This feature is open loop and depends on the VE or TPS maps being accurately tuned for Lambda=1 as it simply calculates the fuel to add to that already calculated.

If the Eco/Power switch is set to Power during autotune the target Lambda is whatever is in the Drivers Desired Lambda.

Sorry about the pdf but hopefully you can get the idea.

[2005bully]

http://www.kiwibiker.co.nz/forums/showthread.php/158975-Yamaha-YZ-250-EFI
<iframe width="560" height="315" src="https://www.youtube.com/embed/1YG9ko8-Nwk" frameborder="0" allowfullscreen></iframe>

http://youtu.be/hOGZ5llowoU


WOW!! Several months back I thought that I saw something on KB about an EFI YZ250 running methanol. But was unable to find it later. Thanks a lot guy's....This is great!!!!
Kermit Buller

[TZ350]

WOW!! Several months back I thought that I saw something on KB about an EFI YZ250 running methanol. But was unable to find it later.

This YZ250 and the Kawasaki Bighorn are running 100% E85, not methanol. I just checked and the Ecotrons pumps are not supposed to be used with Methanol or Gasoline plus Water.

A list of their components and data sheets can be found here:- http://www.ecotrons.com/support/

[husaberg]

WOW!! Several months back I thought that I saw something on KB about an EFI YZ250 running methanol. But was unable to find it later. Thanks a lot guy's....This is great!!!!
Kermit Buller
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[speedpro]

Now that I have my rolling road working I have been running the bike and using the "autotune" feature. It's taken a bit to get my head around how it works but I'm on top of it now. All the manuals say that with the Eco/Power switch set to 0 or Eco that it should autotune to Lambda=1. However it has been tuning to a lower value meaning richer. It seems to aim for about 13.1:1, on the ALM gauge, rather than 14.7:1 which is Lambda=1. The ECU log file was indicating around Lambda=1. I was checking through the ALM manuals tonight and found one that gave slightly different values of Lambda for 0v and 5v.

My ALM was configured for 0v@Lambda=0.5 and 5v@Lambda=2. In test mode this gave an output of 1.667v at Lambda=1 and 1.33v at Lambda=.9
I reconfigured the ALM for 0v@Lambda=0.7 and 5v@Lambda=1.95. In test mode this gave an output of 1.2v at Lambda=1 and 0.8v at Lambda=.9.

So originally my ALM was configured to output a higher voltage at any particular Lambda. The ECU tuned the engine richer to obtain the required voltage it expected for Lambda=1, possibly 1.2v, which has resulted in my autotune map running the engine a bit rich. 1.2v would be Lambda=.8? which is what I was seeing on the ALM gauge.

I'm not worried about it as I want to run a bit rich with the turbo anyway and the idea is to map the fuel requirements. If I decide to run a bit richer it is simply a matter of multiplying each value by some amount.

What I have been doing with the autotune data, only the VE table in my case, is exporting the data and then importing it to the regular manual tuned VE table. This is one method of retaining your autotune date in the event of some sort of problem with the ECU where your autotune date is lost. If there is a problem and you lose autotune data, if the VE table has been updated, you can reset the autotune data to default which imports the current VE & TPS tables which it then tunes automatically. This is the only way to manually alter the autotune data - resetting to default which imports the current manual tables.

I ran the bike last on John Connor's inertia dyno to check ignition timing requirements by actually measuring power. Found that it likes a bit of advance. The problem was that running a bit of boost and revving through to 16,000rpm it was leaning off quite a bit, nore than I liked that's for sure. This was expected as the autotune had only been run up to 1bar and about 14,000rpm. It had filled in values to the end of the tables but it was a flat plane in the 3D view rather than the expected hump. What I did was export the autotune data, imported the data into a VE table and manually edited a hump into the values out to 1.6bar and 16,000rpm. I can run that VE table in normal mode and/or import the default data to autotune and the updated values will be where the autotune will then start from.

[speedpro]

I've had it back on the rolling road. 1/2 confident of the ignition timing, fuel pressure is good, injector pulse width is topping out at about 5mS or about 70% of the time available.

It was in autotune with the ALM output as it came so the ECU was tuning for what was actually a bit rich, but what it thought was Lambda=1. The engine ran flawless at a few throttle settings under 100% and you could see it hunt over and under Lambda=1 with a diminishing swing each time until it settled more or less on 1. Finally ran it at 100% which because of the setup it switched to the TPS table, set for anything over 98% throttle. The TPS table had what was probably values for a Kawasaki Gpz250 which the kit is from and the 3D chart showed a pretty typical fuel map. I ran it at 100% and at 10, 12, 14, and 16,000rpm. Very interesting effect on the TPS table. Even though the throttle was only ever at 100% when the table was tuned EVERY value in the table was altered. Now the 3D chart is a flat plane sloping down from the 100% values. Supposedly it reached 140% load which is probably about right with the turbo.

What I have decided is to alter the ALM output to the correct values as per the latest version of the ALM manual. In the self test this has the effect of causing 1.2v to be output at a test Lambda of 1. The ECU indicates Lambda=1 as well so now they match. Next time I have it on the rolling road I will set the Eco/Power switch to 1 which will make the autotune software tune to the Drivers Desired Lambda values rather than 1. It should only make a small change as the current autotune table values in the engine are a bit rich already.

Tuning mostly done I spent a bit of time just pissing with the throttle and I can't fool it. One thing I did check was if the waste gate was working but it's only managing about 1.2+bar so no activity. Funnily it manages 1.2bar from about 10,000rpm but doesn't seem to increase with revs, could be a tuning thing.

Once finished I exported the autotune date to a CSV file, cycled the power, checked all was still good and then bought it home, aaaaand, the ECU didn't start the fuel pump when power was turned on. It took 5-6 tries before the pump started. When I checked this time the autotune tables were blank. I've done the process of loading the autotune date into the regular VE and TPS tables and then reset the autotune data to default which imports those tables to the autotunetables so nothing lost, thankfully.

One other thing I noticed was that the throttle had to be opened a small amount before the TPS indicator registered movement. As previously I "flashed" the ECU and now it is back to working properly. Doing this blanked the autotune tables again, which supposedly it shouldn't.

Tonight when I powered it up the fuel pump again did not start on the first try. Hopefully it isn't the ECU on the way out. I have a spare pump from Rob so will swap it out if the problem persists.

If the weather is OK I'm looking to have a ride around on Saturday at Mt Wgtn.

[TZ350]

Certainly nearly driven me crazy learning what to do ...... :laugh:

But tackling new chalanges is the Bucket way.

319293319294319292

EFI 2T, three injectors, Throttle body with TPS and dyno chart with runs at different throttle openings.

I have found the trick is to use split injection for high and low power and the smallest low power injector possible because that gives the widest range of tunability for closed or trailing throttle under 30% TP (throttle position).

The low power runs on the graph show that I have not got the nearly closed throttle fuelling anywhere good enough to be useful on the track yet.

319292

100% TP = 27hp
50% TP = 24hp
40% TP = 20hp
30% TP = 12hp
(TP = throttle position)

From 60% to a 100% TP typically (for any engine) there is not a great change in power, 25 - 27hp, a 2 hp change and consequent fuel demand in this case. The tricky fueling problems are all in the area between 0 to 40% TP, which is a 20hp change or ten times the variation in fuel demand as 60 to 100% TP on my EFI engine.

So you need a primary injector that can be turned right down to next to nothing and ramped right up to 50% of the total fuel demand. The secondary big injector, actually the two side injectors fired together as a pair in my case need to be larger but their on time does not vary nearly as much as the single smaller injector needs too.

Hopefully get the new bike finished soon so I can get back onto developing the EFI thing.

So there we have it, a 2T EFI Bucket wannabe.

Now that I have a good F5 bike of my own I am very much looking forward to getting back to this EFI project.

[speedpro]

I have the rolling road now if you want to run it at constant speed and load.

[TZ350]

The two stroke EFI story so far with pictures if you follow the links back to the original posts.


Posted because someone asked where to find it all, so a recap on the basics of the Beasts Engine.


TeeZee tested his 24 against a 30 in a back to back test. The 30 didn't make anymore power than the 24.


Ok, making a bit of progress with setting up the EFI systems throttle body.


Det Sensor. Next week I hope to get all the chopping and changing of the wiring done then I can start playing with setting up the Ecotrons EFI program for a trial run...


The mid chamber bleed re visited as it might be useful for some low end boost......


One of the most useful things I have added to the fuel injection system is a switch that turns the fuel pump off.


Tim gave me a hand tonight, we started to make progress when we moved the injection end point. I think we originally had the injector squirting into closed ports.


Flettner makes the point that it is important, in fact the whole key to successfully fuel injecting a two stroke, is to have the injection period timed to end at the transfer port closing.


First cut at verifying the timing of the injection end point.
Lashed a regular trigger coil to a 12V solenoid with a bolt through it. Set the Ignitec map to zero, now it will fire immediately it sees a trigger pulse.


Spent sometime tonight trying to figure out why there was no signal at the injector. Then realized that at TPS = zero the injection map is = to zero. So bumped the first line up to 100 and bingo the injectors were firing.


The next move is to try the lash up Flettner suggested, and yes I still had sparks and by switching the leads plugged into the injector socket I could easily figure out which was the injector energizing and shut off points. And now I can setup the injector close point and with the timing light I can clearly see where the injection events are happening on the flywheel.


Ok ..... I dusted off my old valve powered signal generator and oscilloscope. And brought some science to the problem, and it looks like it is not me.

Later realised it was me, I did not have the steps in the map as even as they needed to be in real life and when the ECU tried changing between injectors with the engine under load it was tripping over a step and becoming confused.


Connected up a signal generator and oscilloscope to the Beast and had a look at how the EFI injector pulses behaved at a simulated 2,000 to 12,500+ rpm. And then with the motor running. Five things I learned about my EFI setup today.


Ok finally got the O2 and exhaust temperature sensors installed. No idea if they are in the optimum place but they will do for a start. Now that it all seems to be working I am really looking forward to getting a bit of time on the dyno to play with this thing.


I am now starting to make some headway with tuning the Beast and I am beginning to enjoy using the Ecotrons small engine EFI kit for two strokes and its 2T tuning software. Recorded some RPM and TPS data along with the Lambda O2 sensor.


Ok, making progress, that's if you can call getting it wrong progress. Ecotrons has a very clever self tuning feature where you tell the map what Lambda you want at what RPM and the ECU will read the ALM O2 sensor and adjust the mixture for you. Being able to make planned mistakes is a step better than just making ignorant mistakes and not knowing why. So .... its progress.


Posted because I was recently asked about the det sensor I used. I earthed one of the two wires. Probably does not matter which.


The detector/amplifier I got of Ebay comes with lights and I currently use an optional extra output to signal the ignition to retard when there is detonation.


Started making a new injector manifold that points the small Ecotrons injectors across the transfer port windows, previously the outside pair had just fired straight into the B transfer ports and impinged on the back of the cylinder liner.


Making some progress with the new fuel injection manifold. The injectors are angled so they squirt more horizontally across the transfer port. The small (bottom left) injector from the Ecotrons Small Engine EFI kit for two strokes has had the clips on its top cut back so the fuel barb can be swiveled in different directions.


Unlike finicky carburetors, with fuel injection there is not the over enriching problems you get when the inlet stream bounces back and forth several times in the inlet tract. Passing the carbs needle jet several times and picking up fuel on each pass. With EFI I don't have to be so conservative with the rotary valve timing and can experiment a little.


New injector manifold to direct the fuel streams across the transfer ducts. There will be three 126 g/min injectors, with the middle one firing first then the outer ones come in when the engine gets up on the pipe. The center injector is angled up so as to cool the underside of the piston crown by squirting through a slot in the piston skirt.


The plenum re visited ... The problem was, with the carb on the outside we got excessive fuel dropout in the plenum, EFI should cure that.


Started work on the fueling map, things are starting to come together, but probably making adjustments in to big a steps. More patience is required. When I shut the throttle after a 12k pull the motor sounded like a hive of angry hornets, to lean on over run.

The big learn of the night was the truth of the quote below.

"" One thing you have to always remember with alpha-N is that you don't actually know where the effective WOT is any more (i.e., when you have enough throttle that opening it further doesn't affect the amount of air being ingested). At low RPM WOT could be only 20% throttle. ""


Ok this is where my thinking is at tonight, possibly wrong but there you are. So I am none to sure about how useful the BSFC would be as it looks more rpm and engine efficiency than load dependent.

But what interests me is the Delivery Ratio as I think this is the total volume of air that is passing through the motor and as we all know fuel and air needs to be mixed at a set ratio, even if some of it gets wasted out the exhaust.


I knew the VE table was all about cylinder filling and I thought the cell values on an Alpha-N table were all about the volume of fuel to squirt but I have had to re-think that. From the Ecotrons manual. LOAD based Alpha-N system. For two-stroke engines, the default fuel mapping is Alpha-N method.


For my bike, at 12k ish the delivery ratio is about 120% of the cylinder volume and the amount of air (charging ratio) in the cylinder at BDC is only about 80% of the delivered air and less than that actually gets trapped (trapping efficiency) at exhaust port closing, so you can see that a fair swag of air is lost out the exhaust port. And my guess is that the bulk of the air that is lost is the first air entering the cylinder as the transfers start to open and if there was extra fuel already in the transfers that would be lost with it.


Now the opening time can start before the transfer opens and the close time after so that leaves me a clear 1.5 to 1.7ms of full on injection time. The start point can be early but it looks as if the timing of the injection end point is going to become critical if we are going to get the bulk of the injection happening towards the end of the transfer event.


That is pretty much what I have been trying to achieve with the upwards directed injection stream from the central injector.


If a carburettor has one advantage over fuel injection, this is it. When the quantity of fuel is controlled via the open/shut time of an injector, it is practically impossible to create a homogeneous mixture at the injector. And I'm not even talking about vaporized fuel here; I'm just talking about every part of air getting the same number of fuel droplets. Fortunately for us much of the necessary homogenisation takes place in a two-stroke's crankcase, with the con rod stirring things up and transferring its heat to the yet-unvaporized fuel droplets. But with direct fuel injection you lose this advantage, and the con rod bearing looses most of its cooling.


Hi Speedpro, I agree with everything you say but "weak mixture - no", well not in this case because this engine runs well with a carb but not with transfer port injection EFI so the problem must be with the EFI or at least with the way I am trying to use it.

Remember with a carb all inducted air has fuel mixed with it but with EFI this is not necessarily true. The problem with EFI and transfer port injection is that as the rpm gets up, a lot of air can get through the port but there is not necessarily enough time to inject sufficient fuel into the air stream.


Making progress, touching 12,000 rpm and nearly 25hp 3 to go.


26 hp and repeatable, but so fiddly to get and still detos like mad, however much fuel I throw at it. All the extra fuel does is make more exhaust smoke.
I think there really is just not enough time, 1.8ms for the injection cycle through the transfers at 12krpm. Ok time to change over to injecting down the inlet tract.


Ok, rearranged the injectors, injector one is still in the rear of the cylinder and injector two is firing down the carb. With the injection cycle timed to end at inlet closing. Red line is both injectors in the rear of the cylinder. Blue line is with the second injector in the inlet tract. The lines diverge at the point the inlet injector takes over. Its interesting because it goes to show that carbs can be pretty good.


The Blue line is my best with transfer port injection the Green line is where I have got to today with the twin injectors aimed down the inlet throat. It was the same map as the transfer port injection, and better than yesterday's single injector effort.


Well tonight's effort was a total bust, the two injectors send out such a cloud that it wets out on the bellmouth and dribbles down into the plenum which totally negates the reason for having injectors in the first place. Ie to stop fuel pooling in the plenum.

I can see the advantage of having the injectors behind the throttle slide like they have on the BRC engine. Gave up for the night after the EFI filled the crankcase with raw fuel.


Alpha-N maps need to be smooth without any peaks or severe troughs between cell steps. Ecotrons has a function where you can export a map to an Excel spread sheet and use the charting function to help smooth the map data. Raw data and the chart showing how rough the data is and the engine ran just as roughly. Smoothed data and chart.


Making progress towards the magic 28, at least now I know this EFI thing is going to work. Just a lot of careful step by step adjustment of the maps is required. I expect time and patience will see it running very nicely. I also thought it had a terminal deto problem. Deto turned out to be the piston hitting the head.


27.6hp - getting close with EFI to the best ever achieved with a carb on this cylinder. Blue line is where we started, Red line is where we are now. The big issue is getting back on the gas and running to rich below 8,000 rpm. Anyway it is coming right bit by bit.


The EFI is touching 28, but its still very reluctant to come back on the throttle after rolling off.

It will be a pig to ride so I guess I will take my laptop to Tammers and the weekend for me will be all about starting off the back of the grid and adjusting the EFI map to try and get the Beast track ride-able.

I am looking forward to it as I might have more luck getting it right by riding it than trying to tune its low to mid range on the dyno. Anyway the weekend away camping with every one else will be fun and the local RSA does a real great Saturday night dinner ..... Yum ... :p

Tammers was a bust, Bike was a real pig to ride.


Ok after months in the wilderness I finally figured it out. I was right about needing smaller injectors. So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really .... :facepalm: Not perfect yet but very very promising.

With a smaller primary injector things start to come right.


Injectors turned up from Ecotrons today, four days from date of order and two of them were weekend days, pretty good service in my books. I fitted a smaller injector and did a bunch of runs at different throttle settings. Interesting that the 60, 50 and 40% runs carry on out to close to 13,000 rpm. Blue line is the TPS. 100-90-80-70-60-50-40% throttle settings. It is certainly throttling and coming back onto the power much better. I will have to analyse the data to see if I can use an even smaller injector.


The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.

I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between the values of adjacent cells.

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.


Carburetors are great because of their analog ability to change the fuel delivery with changes in air flow at the same throttle setting. EFI, well EFI is not forgiving at all.

The Ecotrons Alpha-N map has 16 rows to work with and I had concentrated them in the area where the power is, as you do. Well that turns out to be a mistake because there is not much difference in fuel demand per cycle between 100% throttle and 90 or 80 or even 70 at max power and virtual no difference at all above 40% in the 3 to 6000 rpm range.

The big jumps were between the lower throttle settings where there was not much excitement happening, well the mistake is that the CPU has a hard time bridging the big gaps below 40% especially when it is also trying to swap between low and high injectors at the same time.

As it turns out, it was a mistake to concentrate my map in the power area, but I guess I will forgive myself..... :laugh:

29hp


Different problem, but I feel your pain Dave. Been working my arse off on this EFI thing. 90% throttle consistently makes more power than a 100%, 80's pretty close to and 70 is not far behind.

309768

I keep making more power but can't get it to come back onto the throttle properly.

I just want it to throttle properly so I can ride it , Bah humbug, and stamp my feet.


Finally getting some place with the EFI after strapping a small laptop onto the tank and riding the bike around looking for the bad spots in the map. I can now wind it out, throttle off and have it come back onto the throttle again. Its now ride-able enough to make it worth taking to a practice day for further refinement. Dyno runs recorded at 100-90-80-70-60-50-40 and 30% throttle.

I have made more power in the past but the point of these dyno runs is that it is running reasonably well at different throttle openings and it is also something of a guide for refining the Alpha-N map some more.

Its a two stage injector system with three injectors, the middle 60 g/min unit is for starting, slow running and over run after shutting off. A pair of 80 g/min units provide fuel as the engine comes on the pipe then the middle injector chimes in again so all three are firing as the rev's get around 10,000 rpm.

I checked the data logger and the middle injector is chiming back in at 9,500 rpm on WOT so I have achieved one of may aims, squirting raw fuel at the underside of the piston crown to cool it when the engine is making real power, I am very happy with that.

The biggest issue was selecting the right sized injectors, I had chosen ones that were to big, to big and there is not enough range of tuning adjustment and it took a while to work my way down to quite small injectors.

The quest for even steps on the Alpha-N map.


Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.



Now to map it all out.



320596

320597

Job done, now to see if it actually works.

[TZ350]

Page 1 ....

There is very little information that I can find on the net about what a two stroke electronic fuel injection map should look like or how to develop one.

320520

Once I started to understand how EFI worked it was relativly easy to get full power runs but it was quite hard to develop a map that is good for part throttle and transition from full throttle to closed and back to open again. This has been the biggest issue holding me back from having a track ready EFI bike.

I was stuck for a long time until I realised I need to use the smallest injector possible to give myself the widest tuning range. So the lesson here is; use the smallest injector possible that you can get away with, not the largest.

320521

Once I realised that I was able to develop a map that more or less works down to 30% throttle but under that it is still rat shit.

So I figured it is time to bring some science to the party. And found this air flow vis throttle position curve. Increases in airflow do not follow throttle position. The biggest changes in airflow are between 20-40% throttle.

320522

Airflow on the left and throttle position along the bottom. Airflow vis TPS summarized on the right.

320523

I took the throttle numbers from the airflow vis throttle position curve and ran them through the EngMod2T model for my air cooled engine.

Throttle position numbers used:- 3 - 5 - 7 - 13 - 20 - 27 - 33 - 40 - 47 - 52 - 57 - 61 - 67 - 78 - 87 - 100%

The objective was to get a series of evenly spaced "Transfer Ratio" curves. Transfer ratio represents the amount of air transferred to the cylinder and this amount of air needs fuel added to it in the correct amount.

I originally tried to work with simulated torque curves but torque is a product of transfer ratio and trapping efficiency. The torque curves did not take account of air that was transferred but not trapped. So basically with crankcase or transfer port injection torque underestimates the amount of fuel needed for correct mixture strength of the trapped air as some air/fuel is unavoidably lost but needs accounting for. Direct cylinder injection would be different and cleaner but beyond what I can manage engineering wise at the moment.

320519

At 4,000 rpm the transfer efficiency at 40 and 61% throttle is greater than at 100%, this needs to be reflected in the map.

[TZ350]

Page 2 ....

320524

I found that I needed a value of 65 in the EFI map cell that represented full throttle at 9,000rpm and slightly less at 12,000 rpm. This 65 is just one cell number and depends on my injector size, and the amount of air ingested at that point. But from this known starting point and the EngMod simulations we can develop a map.

Because pretty much all performance two strokes will have a curve with a steep transition that looks something like mine. I am posting all the simulations with their values so anyone else can use them as a rough guide. All they have to do is find their starting point and adjust my RPM points to suit their power curve.

All I have to do now to develop my map is some maths using my "65" starting point and the simulated delivery ratio numbers to find values for each cell on the map. The Ecotrons Alpha-N map is 16 by 12, 16 TPS values and 12 RPM points. Other maps may be different.

320526 320525 3,500 rpm

320528 320527 4,000 rpm

[TZ350]

Page 3 ....

320530 3205375,000rpm

320532 320533 6,500rpm

320547 320546 7,000rpm

[TZ350]

Page 4 .....

320548320549 7,250rpm

320541 320542 7,500rpm

320545 320544 8,250rpm

[TZ350]

Page 5 ...

320551 320550 9,250rpm

320553 320552 11,000rpm

320557 320556 11,750rpm

[TZ350]

Page 6 ...

320559 320558 13,000rpm

With these simulated charts and my known good number 65 from the old map cell corresponding to 100% TP at 9,250 I can generate new numbers for each cell for my new map.

320563 9,250rpm

I know 65 from 100% TP and 9,250rpm on my old map was a good number and from the simulations I that 65 relates to a transfer ratio of 1.3 or in other words 1.3 times the cylinder volume was transferred up to the cylinder and it took 65 on the old map for the EFI to squirt enough fuel into the engine at that point for good power.

So now I have to normalise the simulated numbers so I can use them to estimate from the known good number 65 what each new value should be for every cell position on the map.

So we know for 9,250rpm and 100% TP 1.3 transfer ratio = 65

So for cell position 9,250rpm and 87% TP = 1.244/1.3 * 65 = 62.2

So for cell 9,250 rpm 87% TP the new value is 62.2

Now I only have to do this calculation for 190 more cells and I will have my new map, how hard can that be ..... :wacko:

[speedpro]

Simple in XL

[TZ350]

Simple in XL

Yes, and that is the next step. I will post it when I get it done.

[AndreasL]

Love it TZ! 👍

[Cheesy]

Is your injector dead time going to throw this calculation out at lower engine speeds if you are pushing the range on the injector?

[TZ350]

Is your injector dead time going to throw this calculation out at lower engine speeds if you are pushing the range on the injector?

I am not sure. There is a minimum on time of 1.8ms to get these injectors fully open. so any injection event has to be for more than 1.8ms otherwise the engine over fuels.

You might only need 0.001cc per injection.

A bigger injector can deliver 0.001cc in 0.9ms but there is a minimum on time of 1.8ms so the bigger injector delivers twice as much fuel as needed and can not be turned down any lower than 1.8ms.

A smaller injector might deliver 0.001cc in 2ms, so a smaller injector can be turned down to deliver the right amount of fuel.

The trick is to use a smaller injector so it squirts less fuel and so needs to be turned on for longer that way you get finer low speed fueling control.

320575

I am using three injectors in a staged setup. The inner one does the low speed work. Then it changes to the outer two who do all the work from about 7K to 10K rpm at which point the first joins them again and helps out when the complete 360 deg crank rotation time starts to shrink and squeeze the possible injection on time.

320577

I have had some successes with full throttle runs

[mr bucketracer]

I am not sure. There is a minimum on time of 1.8ms to get these injectors fully open. so any injection event has to be for more than 1.8ms otherwise the engine over fuels.

You might only need 0.001cc per injection.

A bigger injector can deliver 0.001cc in 0.9ms but there is a minimum on time of 1.8ms so the bigger injector delivers twice as much fuel as needed and can not be turned down any lower than 1.8ms.

A smaller injector might deliver 0.001cc in 2ms, so a smaller injector can be turned down to deliver the right amount of fuel.

The trick is to use a smaller injector so it squirts less fuel and so needs to be turned on for longer that way you get finer low speed fueling control.

320575

I am using three injectors in a staged setup. The inner one does the low speed work. Then it changes to the outer two who do all the work from about 7K to 10K rpm at which point the first joins them again and helps out when the complete 360 deg crank rotation time starts to shrink and squeeze the possible injection on time.

320577

I have had some successes with full throttle runsshe's looking good now

[TZ350]

Simple in XL

320596

320597

Job done, now to see if it actually works.

[TZ350]

The EFI story with pictures if you follow the links back to the original posts.


Posted because someone asked where to find it all, so a recap on the basics of the Beasts Engine.


TeeZee tested his 24 against a 30 in a back to back test. The 30 didn't make anymore power than the 24.


Ok, making a bit of progress with setting up the EFI systems throttle body.


Det Sensor. Next week I hope to get all the chopping and changing of the wiring done then I can start playing with setting up the Ecotrons EFI program for a trial run...


The mid chamber bleed re visited as it might be useful for some low end boost......


One of the most useful things I have added to the fuel injection system is a switch that turns the fuel pump off.


Tim gave me a hand tonight, we started to make progress when we moved the injection end point. I think we originally had the injector squirting into closed ports.


Flettner makes the point that it is important, in fact the whole key to successfully fuel injecting a two stroke, is to have the injection period timed to end at the transfer port closing.


First cut at verifying the timing of the injection end point.
Lashed a regular trigger coil to a 12V solenoid with a bolt through it. Set the Ignitec map to zero, now it will fire immediately it sees a trigger pulse.


Spent sometime tonight trying to figure out why there was no signal at the injector. Then realized that at TPS = zero the injection map is = to zero. So bumped the first line up to 100 and bingo the injectors were firing.


The next move is to try the lash up Flettner suggested, and yes I still had sparks and by switching the leads plugged into the injector socket I could easily figure out which was the injector energizing and shut off points. And now I can setup the injector close point and with the timing light I can clearly see where the injection events are happening on the flywheel.


Ok ..... I dusted off my old valve powered signal generator and oscilloscope. And brought some science to the problem, and it looks like it is not me.

Later realised it was me, I did not have the steps in the map as even as they needed to be in real life and when the ECU tried changing between injectors with the engine under load it was tripping over a step and becoming confused.


Connected up a signal generator and oscilloscope to the Beast and had a look at how the EFI injector pulses behaved at a simulated 2,000 to 12,500+ rpm. And then with the motor running. Five things I learned about my EFI setup today.


Ok finally got the O2 and exhaust temperature sensors installed. No idea if they are in the optimum place but they will do for a start. Now that it all seems to be working I am really looking forward to getting a bit of time on the dyno to play with this thing.


I am now starting to make some headway with tuning the Beast and I am beginning to enjoy using the Ecotrons small engine EFI kit for two strokes and its 2T tuning software. Recorded some RPM and TPS data along with the Lambda O2 sensor.


Ok, making progress, that's if you can call getting it wrong progress. Ecotrons has a very clever self tuning feature where you tell the map what Lambda you want at what RPM and the ECU will read the ALM O2 sensor and adjust the mixture for you. Being able to make planned mistakes is a step better than just making ignorant mistakes and not knowing why. So .... its progress.


Posted because I was recently asked about the det sensor I used. I earthed one of the two wires. Probably does not matter which.


The detector/amplifier I got of Ebay comes with lights and I currently use an optional extra output to signal the ignition to retard when there is detonation.


Started making a new injector manifold that points the small Ecotrons injectors across the transfer port windows, previously the outside pair had just fired straight into the B transfer ports and impinged on the back of the cylinder liner.


Making some progress with the new fuel injection manifold. The injectors are angled so they squirt more horizontally across the transfer port. The small (bottom left) injector from the Ecotrons Small Engine EFI kit for two strokes has had the clips on its top cut back so the fuel barb can be swiveled in different directions.


Unlike finicky carburetors, with fuel injection there is not the over enriching problems you get when the inlet stream bounces back and forth several times in the inlet tract. Passing the carbs needle jet several times and picking up fuel on each pass. With EFI I don't have to be so conservative with the rotary valve timing and can experiment a little.


New injector manifold to direct the fuel streams across the transfer ducts. There will be three 126 g/min injectors, with the middle one firing first then the outer ones come in when the engine gets up on the pipe. The center injector is angled up so as to cool the underside of the piston crown by squirting through a slot in the piston skirt.


The plenum re visited ... The problem was, with the carb on the outside we got excessive fuel dropout in the plenum, EFI should cure that.


Started work on the fueling map, things are starting to come together, but probably making adjustments in to big a steps. More patience is required. When I shut the throttle after a 12k pull the motor sounded like a hive of angry hornets, to lean on over run.

The big learn of the night was the truth of the quote below.

"" One thing you have to always remember with alpha-N is that you don't actually know where the effective WOT is any more (i.e., when you have enough throttle that opening it further doesn't affect the amount of air being ingested). At low RPM WOT could be only 20% throttle. ""


Ok this is where my thinking is at tonight, possibly wrong but there you are. So I am none to sure about how useful the BSFC would be as it looks more rpm and engine efficiency than load dependent.

But what interests me is the Delivery Ratio as I think this is the total volume of air that is passing through the motor and as we all know fuel and air needs to be mixed at a set ratio, even if some of it gets wasted out the exhaust.


I knew the VE table was all about cylinder filling and I thought the cell values on an Alpha-N table were all about the volume of fuel to squirt but I have had to re-think that. From the Ecotrons manual. LOAD based Alpha-N system. For two-stroke engines, the default fuel mapping is Alpha-N method.


For my bike, at 12k ish the delivery ratio is about 120% of the cylinder volume and the amount of air (charging ratio) in the cylinder at BDC is only about 80% of the delivered air and less than that actually gets trapped (trapping efficiency) at exhaust port closing, so you can see that a fair swag of air is lost out the exhaust port. And my guess is that the bulk of the air that is lost is the first air entering the cylinder as the transfers start to open and if there was extra fuel already in the transfers that would be lost with it.


Now the opening time can start before the transfer opens and the close time after so that leaves me a clear 1.5 to 1.7ms of full on injection time. The start point can be early but it looks as if the timing of the injection end point is going to become critical if we are going to get the bulk of the injection happening towards the end of the transfer event.


That is pretty much what I have been trying to achieve with the upwards directed injection stream from the central injector.


If a carburettor has one advantage over fuel injection, this is it. When the quantity of fuel is controlled via the open/shut time of an injector, it is practically impossible to create a homogeneous mixture at the injector. And I'm not even talking about vaporized fuel here; I'm just talking about every part of air getting the same number of fuel droplets. Fortunately for us much of the necessary homogenisation takes place in a two-stroke's crankcase, with the con rod stirring things up and transferring its heat to the yet-unvaporized fuel droplets. But with direct fuel injection you lose this advantage, and the con rod bearing looses most of its cooling.


Hi Speedpro, I agree with everything you say but "weak mixture - no", well not in this case because this engine runs well with a carb but not with transfer port injection EFI so the problem must be with the EFI or at least with the way I am trying to use it.

Remember with a carb all inducted air has fuel mixed with it but with EFI this is not necessarily true. The problem with EFI and transfer port injection is that as the rpm gets up, a lot of air can get through the port but there is not necessarily enough time to inject sufficient fuel into the air stream.


Making progress, touching 12,000 rpm and nearly 25hp 3 to go.


26 hp and repeatable, but so fiddly to get and still detos like mad, however much fuel I throw at it. All the extra fuel does is make more exhaust smoke.
I think there really is just not enough time, 1.8ms for the injection cycle through the transfers at 12krpm. Ok time to change over to injecting down the inlet tract.


Ok, rearranged the injectors, injector one is still in the rear of the cylinder and injector two is firing down the carb. With the injection cycle timed to end at inlet closing. Red line is both injectors in the rear of the cylinder. Blue line is with the second injector in the inlet tract. The lines diverge at the point the inlet injector takes over. Its interesting because it goes to show that carbs can be pretty good.


The Blue line is my best with transfer port injection the Green line is where I have got to today with the twin injectors aimed down the inlet throat. It was the same map as the transfer port injection, and better than yesterday's single injector effort.


Well tonight's effort was a total bust, the two injectors send out such a cloud that it wets out on the bellmouth and dribbles down into the plenum which totally negates the reason for having injectors in the first place. Ie to stop fuel pooling in the plenum.

I can see the advantage of having the injectors behind the throttle slide like they have on the BRC engine. Gave up for the night after the EFI filled the crankcase with raw fuel.


Alpha-N maps need to be smooth without any peaks or severe troughs between cell steps. Ecotrons has a function where you can export a map to an Excel spread sheet and use the charting function to help smooth the map data. Raw data and the chart showing how rough the data is and the engine ran just as roughly. Smoothed data and chart.


Making progress towards the magic 28, at least now I know this EFI thing is going to work. Just a lot of careful step by step adjustment of the maps is required. I expect time and patience will see it running very nicely. I also thought it had a terminal deto problem. Deto turned out to be the piston hitting the head.


27.6hp - getting close with EFI to the best ever achieved with a carb on this cylinder. Blue line is where we started, Red line is where we are now. The big issue is getting back on the gas and running to rich below 8,000 rpm. Anyway it is coming right bit by bit.


The EFI is touching 28, but its still very reluctant to come back on the throttle after rolling off.

It will be a pig to ride so I guess I will take my laptop to Tammers and the weekend for me will be all about starting off the back of the grid and adjusting the EFI map to try and get the Beast track ride-able.

I am looking forward to it as I might have more luck getting it right by riding it than trying to tune its low to mid range on the dyno. Anyway the weekend away camping with every one else will be fun and the local RSA does a real great Saturday night dinner ..... Yum ... :p

Tammers was a bust, Bike was a real pig to ride.


Ok after months in the wilderness I finally figured it out. I was right about needing smaller injectors. So it looks like, to maximize tune-ability you need to minimize the injector size......... in hindsight its so obvious really .... :facepalm: Not perfect yet but very very promising.

With a smaller primary injector things start to come right.


Injectors turned up from Ecotrons today, four days from date of order and two of them were weekend days, pretty good service in my books. I fitted a smaller injector and did a bunch of runs at different throttle settings. Interesting that the 60, 50 and 40% runs carry on out to close to 13,000 rpm. Blue line is the TPS. 100-90-80-70-60-50-40% throttle settings. It is certainly throttling and coming back onto the power much better. I will have to analyse the data to see if I can use an even smaller injector.


The EFI lesson I learnt last month was, that to get the greatest range of tune ability I needed to use the smallest injectors possible that will still do the job. I know, pretty obvious, but there you go.

I read the Ecotrons EFI manual and saw that the map must have as many even steps as possible and I thought that meant dividing the rpm range up as evenly as possible, seemed logical, but wrong again.

The bike bucked around swapping between the staged injectors as the EFI struggled to jump from one cell to another on the steeper parts of the fueling curve.

I guess what they really meant was that the changes between cells need to be as even as possible.

So I don't need even spacing between the rpm break points and can have big or small gaps between them so long as there are no big steps between the values of adjacent cells.

I can now throttle on/off pretty well and do a series of part throttle runs, the last one is at 30% TPS, it looks a bit lean.

Its not perfect but is running a lot better, so for what its worth here is the current Alpha-N map.


Carburetors are great because of their analog ability to change the fuel delivery with changes in air flow at the same throttle setting. EFI, well EFI is not forgiving at all.

The Ecotrons Alpha-N map has 16 rows to work with and I had concentrated them in the area where the power is, as you do. Well that turns out to be a mistake because there is not much difference in fuel demand per cycle between 100% throttle and 90 or 80 or even 70 at max power and virtual no difference at all above 40% in the 3 to 6000 rpm range.

The big jumps were between the lower throttle settings where there was not much excitement happening, well the mistake is that the CPU has a hard time bridging the big gaps below 40% especially when it is also trying to swap between low and high injectors at the same time.

As it turns out, it was a mistake to concentrate my map in the power area, but I guess I will forgive myself..... :laugh:

29hp


Different problem, but I feel your pain Dave. Been working my arse off on this EFI thing. 90% throttle consistently makes more power than a 100%, 80's pretty close to and 70 is not far behind.

309768

I keep making more power but can't get it to come back onto the throttle properly.

I just want it to throttle properly so I can ride it , Bah humbug, and stamp my feet.


Finally getting some place with the EFI after strapping a small laptop onto the tank and riding the bike around looking for the bad spots in the map. I can now wind it out, throttle off and have it come back onto the throttle again. Its now ride-able enough to make it worth taking to a practice day for further refinement. Dyno runs recorded at 100-90-80-70-60-50-40 and 30% throttle.

I have made more power in the past but the point of these dyno runs is that it is running reasonably well at different throttle openings and it is also something of a guide for refining the Alpha-N map some more.

Its a two stage injector system with three injectors, the middle 60 g/min unit is for starting, slow running and over run after shutting off. A pair of 80 g/min units provide fuel as the engine comes on the pipe then the middle injector chimes in again so all three are firing as the rev's get around 10,000 rpm.

I checked the data logger and the middle injector is chiming back in at 9,500 rpm on WOT so I have achieved one of may aims, squirting raw fuel at the underside of the piston crown to cool it when the engine is making real power, I am very happy with that.

The biggest issue was selecting the right sized injectors, I had chosen ones that were to big, to big and there is not enough range of tuning adjustment and it took a while to work my way down to quite small injectors.

The quest for even steps on the Alpha-N map.


Now that my new bike is nearly ready I need to develop a new Alpha-N fuel injection map. The axis's of an Alpha-N map is throttle position TPS and RPM. The steps between cells need to be in even steps. That is not even RPM or TPS steps but even changes in engine load.

"Torque" is largely related to the motors Trapping Efficiency of the air passing through it.

"Delivery Ratio" is everything when it comes to quantifying airflow through a two stroke motor and it is the air flow that needs fuel added to it in the correct proportions. Trapping Efficiency is the measure of how much of this air/fuel is trapped to be com-busted.

Initially I thought changes in Torque could be used to represent changes in engine load and could be used for developing a fuel injection map. Well that might be Ok for a four stroke but now that I have tried that approach I now think that Delivery Ratio is the more suitable measure for developing a two stroke map.

Air flow (Delivery Ratio) through a throttle is not linear. The greatest changes happen between 20 - 40% throttle opening.

320573

The first requirement is to find the throttle openings that corresponds to even Delivery Ratio (air flow) steps.

320572

Then I modeled these throttle openings in EngMod2T and got a reasonable correlation and reasonably even layer of Transfer Efficiency steps in the power region of the simulation.

This information at each TPS position and RPM point should make a handy start for developing the new map.

The rest of the simulation data (all 12 of them) are posted on the Ecotrons thread. Because the Transfer Efficiency graphs are probably similar to any performance 2T with a few adjustments to the rpm points the numbers may make a useful start to any 2T Alpha-N map project.



Now to map it all out.



320596

320597

Job done, now to see if it actually works.


320844

Well.

The good news is that after months of work I have finally given Mr.Bigglesworth a thrashing on the dyno.

The bad news is that there is still a reluctance to come back on the throttle.

320845

Fortunately the Ecotrons EFI software has a data capture function. Max power was at 12250 rpm and max over rev rpm was 12888.

320846

Looking at the left hand courser the yellow line is Inj0 (the small injector) and the blue line Inj1 (the big injector) and the brown line is maximum injection time available. It can be seen that both injectors are topped out at 10,325 rpm. This suggests that Inj1 (the big injector) is to small.

320847

With high rpm and the TPS at 0% Inj0's pulse width is 1.140ms (right hand courser) which is less than the allowable minimum opening time of 1.8ms so on over run Inj0 is still to big.

So the big injector is a touch to small and the small injector is still to big for good tun-ability when throttling off and opening the throttle again like you would negotiating a corner at speed.

Ok, so off to Ecotrons to buy some more injectors.


320857

A fuel injector has a tuning range just like this jet kit has. And just like when you get down to the smallest jet in the kit and still need to go leaner you need a smaller jet kit or injector to move to the next lower tuning range.

That is my problem with the small injector, it is just not small enough to give me the tuning range required to handle the minimum fueling requirements on high rpm over run on a closed throttle. I need the next smaller injector.


Well it is not the end of the story but at least it is progress.

[TZ350]

Some helpful input from Dmcca and Wob on how to use a wideband O2 Lambda sensor to tune a 2T.


The Ecotrons EFI has barometric and air temperature sensors for automatic fueling compensation so hopefully once I am on the money with the dyno the ECU's auto compensation will give pretty much the same results as changing the jets 3 times a day.

I feel very comfortable with tuning the EFI system for maximum power, above 50% throttle position that is relatively easy.

The problem I am struggling with is at the low end, if this was a carb then the EFI bit that is challenging me now is the area covered by a carb's pilot jet and transition to the slide cutaway.


May I ask why you're not using a wideband O2 to tune this area? It would be relatively straightforward with a wideband and a brake dyno.

I started out trying to get a 12.5:1 A/F everywhere on the map, as you do if you don't know any better. Things weren't going well and I gave it away when it was pointed out to me that it was the short circuiting fooling the O2 sensor into thinking the system was running lean when it was not.

It really confused things and it looked like the O2 sensor was not going to be very useful so I discarded it. But your experience encourages me and it looks like that with a bit more experience myself I might be able to get somewhere with it now I have a better idea of what is going on.


Why a brake dyno? Then you would be developing an engine for a set of circumstances that it will never see on a race track. Going through the revs on an inertia dyno and registering revs, torque and lambda simultaneously is an excellent way of establishing an injection map. Besides, running constant revs on a brake dyno with too little fuel or too much ignition advance may kill your engine, whereas it might survive on an inertia dyno.


When i say brake dyno i mean an eddy current or similar that allows both constant rpm tests and normal 'runs'... Im sure that doing only constant rpm tests is not ideal.

Personally I do a combination of both to tune an engine and so far it has worked well for me, especially when tuning the low throttle area that TZ was talking about... in saying that ive only ever had an eddy current dyno, never an inertia-only dyno. And have developed my own methods of tuning without ever seeing first-hand anyone else's process for tuning a two stroke... maybe its a case of ignorance is bliss, however I find my process to be very quick and very reliable for a wide range of engines.

I find that the lambda sensor is a little slow to react at low revs and part throttle. Its fine at higher revs and higher throttle. By holding the engine at a certain rpm point for 3-5sec at each throttle position it gives the readings time to stabilise and gives much better, more repeatable data.

I start by doing a range of fixed rpm tests at different throttle openings, with the revs building higher each test... eg 4000, 6000, 8000, etc at 1/8, 1/4, 1/2, 3/4, full throttle. By doing this you can easily see the areas that need changing (pilot, slide, needle diameter, clip position, needle taper, main jet, etc).

If there is a serious problem with the tune you will always catch it before doing damage as you’ll see AFR's begin to lean out or detonation begin to show before you get too high in rpm. Once I’ve done basic tuning like this then i do full runs and constant load testing and fine tune if necessary, but these are normally only very minor changes.

Whether the AFR reading is showing true AFR or not doesn’t really matter, the numbers can still be used to tune an engine... around full throttle and peak torque it is fairly reliable to use ~12.5:1 and leaner readings below that, down to around 13.5-14:1 at part throttle/low rpm.

Of course you still need to use experience and 'feel' to do the fine tuning but the AFR numbers will get you close. Even if the engine is not actually seeing 14:1 at part throttle/low revs, its still a repeatable data point that can be used to tune an engine. Its certainly a lot better than guessing, especially when tuning the part throttle areas.


+1 the above.Adding that putting the Lambda in the stinger, seems to be way more stable and repeatable when logging the A/F data.

Using data this way is something that you really don’t appreciate how good it is until actually doing it.
Hence TeeZees surprise when I related that every time you change a small item in the engines tune - the dyno result for sure is not telling you really what you want to know, unless you reject every time to hit a predetermined baseline.

As Jan Thiel said, most all of the pipe testing at Aprilia was a complete waste of time, when he finally realised allot of the power differences were down to how the egt reacted to that pipe.

Not that the pipe was "better " for some aspect of scavenging, or trapping efficiency in making more or less power.

[TZ350]

321014

Thanks Husaburg for the Cagiva story, its the same problem I am having.

321016

Shaving down the rich areas on the map. I use Excels formula and graphing functions.

321015

By having a mirror map below that is made up of formula that shaves 0.005 of the top map I can repeatedly transfer values from the bottom map to the top one and by that way shave the Fuel map down in the areas I think are too rich.

321013

I use Excels graphing function to smooth out the lines of the map and to also get nice even steps between the lines.

321017

Great surface visualization feature too.

[TZ350]

Rob, is it time to do a total fundamental reality check? Could it mean taking off all the injectors and chuck on a carb? Means getting rid of the neat throttle valve, but maybe you need to understand if it's some form of injector peculiarity or some unique characteristic of the engine as it has been built.

Have been hoping to avoid reality, this engine has run very well in the past with a carb. But its looking like you are right, it is shaping up to be something about the injectors. Maybe they need to be angled differently.


If the main problem with the carb setup was the fuel and oil that eventually may not reach the engine, maybe, is possible to build the chamber only upside of the inlet pipe, so the gravity kept fuel and oil always on the inlet. May be quite a bit of work and possibly more work/benefit than with the EFI setup, though...

Yes, good idea, we had thought of it but like you say, hard to do on the rotary valve engine but could be very possible to arrange the plenum in such a way it drains into the inlet on a reed or piston porter.


Rob - I'd try the low speed injector on the downstream side of the throttle valve - and aimed at a port wall. From what i've read on 4T injection in low airspeed conditions, you get better results if the injector stream can be made to splatter - for want of a better word...

Good idea, thanks, I might need to look at how I could do that.

Initially it looked like it was anything less than 20% throttle (left cursor) was the problem. But after a bit of time studying the recorded data it is beginning to look more complex.

321105

As the rpm picks up (top line) you can see the rough running smooths out (right cursor) as the difference between injector on time (green line) and the total injector on time available (red line) reduces to 30%. 30% is about the amount of time the transfers are open.

To my surprise the engine runs rat shit when the injector on time is much less than the transfer open time and it gets better when the injector is on for longer than the transfers are open and best when the injector is on the whole time. Actually I suppose that should not be such a surprise because a carb is on for the whole time too, and they run Ok.

After looking at quite a lot of data it looks like the engine runs rough when the injector on time is less than the total transfer open time. The engine runs better the longer the injector is turned on. And of course anything less than 20% throttle there is not much injector on time and the thing runs like a pig.

It must have to do with fuel homogenization. A carb adds fuel to all of the air that passes through it but with an injector, under 30% on time I must be getting big patches of air with no fuel in it. And when the injector has to be on for much longer the air is getting a more consistent mix that is more like that delivered by a carb.

On over rev with the throttle shut there is very little injector on time. So because I can't fire the injector for the full transfer open time. I guess the trick is to find a way to thoroughly homogenize the air fuel mix or at least time the injection point to coincide with the air that will eventually be trapped in the cylinder.

321104

Up till now I have had the big injectors on either side with the slow speed injector in the middle. Maybe worth my while reversing that and trying two small slow speed injectors either side with a really big power injector in the middle. If that results in better mixing and works well then as an extra up side I would be also getting lots of underside piston cooling from the power injector.


The big question is, is how to get a homogeneous mixture of the correct air fuel ratio in the cylinder when the injector is only on for a much shorter time than the transfer window is open.

[TZ350]

321014

Thanks Husaburg for the Cagiva story, its the same problem I am having.

Mr Bigglesworth's Dyno runs.

321016

.... rich areas ....

Initially I thought these were rich areas and to get it running nicely all I had to do was carefully adjust the map in these areas. But I now think the problem is with the injection on time being much less than the transfer port window open time.

[Cheesy]

Is the middle (small) injector squirting into the crankcase? Is it possible to fire the injector earlier at low speed into the crankcase at lower engine speeds to try and get better mixing?

[TZ350]

Is the middle (small) injector squirting into the crankcase? Is it possible to fire the injector earlier at low speed into the crankcase at lower engine speeds to try and get better mixing?

In the Ecotrons EFI software there is a way of mapping (seperate to the fuel map) the injection end point. But I am afraid the Ecotrons manual is not very clear about the details.

321114321115321113

As best as I can tell, that is a 4T map and the Injection end point is so many degrees before TDC on the firing stroke.

For me it would be something like 120 degrees if I wanted to finish the injection squirt as the transfers close.

[speedpro]

Been a while as I only have a few spare hours each week to do any work on the bike. It hasn't come off the dyno for a few months I think. I have taken it off the rolling road, which had been giving good results as far as the Lambda readings were concerned, and put it on the inertia dyno. Tuning the VE table was pretty much sorted and I played with the ignition table by filling tables with one value, say 24degrees and doing runs, then 28degrees and doing runs, etc. Then it was on to the TPS table which I have it set to only be used over 98% throttle. We had tuned it on the rolling road for good Lambda but with the inertia dyno and how it increased revs through a run, and the turbo spooled up, I had to completely rehash it. I took a stack of fuel out below about 10,000rpm where it wasn't really building boost on the inertia dyno, and added a bit more at the top over 14,000rpm.

I was experiencing ECU problems all through this time over a few weeks. I'd change map values at high load and rpm and the engine would refuse to start. I'd load the previous map and away it would go. So I'd try the new map again and this time it would fire straight up and run fine. At one point the engine lost a bunch of power when I tried something and when I reversed that it was still down on power. From previous experience I decided to try flashing the ECU after which the power was back. I also keep having issues with the TPS. Over time it seems that you have to move the throttle further and further before the TPS indicator gauge indicates an increase. Flashing the ECU resets it so that the slightest touch of the throttle causes a change of the TPS gauge reading. You wouldn't initially think this would make a difference since I'm only using the VE table which relies on the MAP sensor output, but the TPS is used to determine whether the engine is being blipped etc and fuel is added or subtracted depending on throttle change rate. The engine definitely blips crisper when it is reading correctly.

#1 header would glow pretty good on a run right at the top of the run. #2 was not so obvious. The engine also struggled over say 14,500rpm and typically was all over by 15,500rpm. Given that I was lied to about the ECU capability to handle revs, and then they gave me a modified version that theoretically allowed 16,000rpm+ I now suspect that the ECU may be reaching it's limits which may be causing #1 to lean out. The Lambda is in the exhaust plenum so reads the combined cylinder o2 value. I was seeing it lean out up top until I tipped in a heap more. Either way I have no confidence that the engine is being managed properly at revs.

Another problem I had which developed quickly to the point where you couldn't even run the bike long enough to warm it up was the ECU losing it's tune and stopping the engine. I knew the ECU had a problem where a connector or something in the case was shorting to ground, which I fixed way back by rubber mounting the ECU. Anyway, I popped the top off the ECU to check for problems. It looked like the main connector pins to the circuit board had not been cut off short enough so I filed them down and then for good measure put electrical tape over them and a few other bits that stuck out further than I thought they needed to. Turns out I was on the money and it has run fine ever since, apart from the problems above.

So, it has got to the point where I pretty much need a Link Atom to progress. Had a very good chat to one of their guys who seemed confident it would be good. Their web site does claim 20,000rpm capability but I got the feeling from talking to him that nobody had tested that yet. On a twin though it shouldn't be a problem. Evidently Link have experimented with using the MAP sensor to determine where in the cycle the engine is but with the revs I'm going to have to fit a cam sensor.

[Drew]

Am I reading this correctly? From what you're saying I infer that Ecotrons is just shit.

[BASS-TREBLE]

Do you have experience with micro/megasquirt? Is there a reason why you are not considering it if you will replace the ecu? The forums have success stories of 16,000+ rpm, I personally have had no problems up to 11,000

[speedpro]

I have no experience with megasquirt. I'm thinking Link for the support. Local product, help is a phone call away, or email, or go to the web, and in English. The manuals seem readable and make sense, as much as I've read anyway. Trying to puzzle the Ecotrons manuals can do your head in.

Ecotrons for the price is very good. I think for their major market, single cylinder 4 strokes, that they do every thing that is asked of them. They are a budget product. As a consequence some of the bits are not as robust as other pricier products, the fuel pressure regulators springs to mind. My faulty one cost me a year of development time and taught me valuable lessons chief of which was "monitor fuel pressure".

There is bugs which may be fixed with software updates but I'm not giving them another US$250 for support to find out.

I have learnt lots though and I truly don't understand why anybody with a 4T uses carbs, except of course that they work and are reasonably simple.

I may be alone in experiencing some of these issues. The ECU software I am running is unique as far as I know so maybe that has raised issues not found in the regular version.

[Flettner]

I have no experience with megasquirt. I'm thinking Link for the support. Local product, help is a phone call away, or email, or go to the web, and in English. The manuals seem readable and make sense, as much as I've read anyway. Trying to puzzle the Ecotrons manuals can do your head in.

Ecotrons for the price is very good. I think for their major market, single cylinder 4 strokes, that they do every thing that is asked of them. They are a budget product. As a consequence some of the bits are not as robust as other pricier products, the fuel pressure regulators springs to mind. My faulty one cost me a year of development time and taught me valuable lessons chief of which was "monitor fuel pressure".

There is bugs which may be fixed with software updates but I'm not giving them another US$250 for support to find out.

I have learnt lots though and I truly don't understand why anybody with a 4T uses carbs, except of course that they work and are reasonably simple.

I may be alone in experiencing some of these issues. The ECU software I am running is unique as far as I know so maybe that has raised issues not found in the regular version.

My LINK (on the F9) is working well, an ATOM, yes they are a bit dearer but you can consult Simon any time at LINK, he knows EVERYTHING.

Neil

[F5 Dave]

So if you float through the Factorypro website they wibble on about matching injectors. I've supplied and ordered a matched set. Apparently its not uncommon to have one rich, one lean etc. Higher revs would only exacerbate the problem.

[Peiter]

Hi guys,

given the interesting results achieved by all of you with injection, I want to give it a shot too together with a friend.
We are planning to implement the ecotrons system as indirect injection on a rotary 50cc yamaha tz 2-stroke engine.

I was wondering what the pros and cons were to indirect injection, compared to direct injection.
Furthermore, having read that TZ has been fiddling quite a bit with the correct injector size for his engine, could you give me advise on what size of injectors I would need to buy?

Thanks in advance!

Peter

[TZ350]

... given the interesting results achieved by all of you with injection, I want to give it a shot too together with a friend. Could you give me advise on what size of injectors I would need to buy?

Ecotrons would be the best bet for Injector sizing advice but below are my thoughts.

I think the Ecotrons system is great for experimenting with but like most EFI systems it may not be suitable for directly injecting into the cylinder after the exhaust port has closed because the cylinder compression pressures will rapidly become higher than the fuel injection pressure.

Like most, the Ecotrons system is suited for transfer port, crankcase, inlet or semi direct injection.

If you are developing your own EFI CPU Ecotrons would be a great source of injector, fuel pump and other parts at very reasonable prices.

327693

Ecotrons fuel Injector specs.

For a high revving two stroke you will need a staged injector system, smaller injector capacity for low speed, larger capacity for high rpm. But selecting an injector is not like selecting a carburettor main jet because it is not all about fuel volume, it is more about the diminishing time in which to get things done as the rpm increases.

Ecotrons is best placed to advise what injector sizes would suit 50 cc 2T but I am currently getting good results with two 60g's and a 128g injector for a total injection capacity of 248g/min on my 110cc 2T engine that tops out at 13,000 rpm. So for 50cc my guess would be about half that, say two 38g's that then swap to 80g for higher rpm and finally finishing with 156g (38 + 38 + 80, all firing together.) .

You want as small an injector as possible. That way you get the widest range of tun-ability. To get it open and flowing in a controllable sort of way an injector has to be "on" for a minimum amount of time to open properly, at least 1.5ms for the small Ecotrons injectors and for a larger injector 1.5ms will be to much fuel for good low speed running.

Car and other bigger injectors typically take 3.5 - 4.5ms or longer to fully open and start flowing properly and so are far too slow for a 14,000 rpm two stroke engine where you barely have that much time in a complete crank revolution let alone the much shorter time the transfer/inlet ports are open.

The EFI dual injection system CPU swaps to the second larger injector when there is no longer enough time for the first smaller injector to deliver enough fuel. As the rpm gets up and time is even shorter the EFI CPU can run both injectors together.

Remember it is all about time. An injector only needs to be big enough to chuck in the right amount of fuel in the short amount of time available at high rpm and not so big that it floods the engine with its minimum on time when there is lots of time available at low rpm for a smaller injector.

A two stage dual injector system uses the first injector until time runs out to get the business done. It then swaps to the second bigger injector to dramatically reduce the time required to chuck the fuel in there. And when that is not enough it starts to run both injectors together so with two different sized injectors you can get a three tier system.

Bigger two strokes like 250 singles that only rev to 9,000 rpm seem to get away with a single stage injector system but when the rev's go past that then a two stage dual injector system is required. Again it is all about the time available to get things done.

An injector goes through four steps each cycle:- Opening - Injecting - Closing - Resting.

Opening takes time, at least 1.5ms and dribbles fuel in an uncontrolled way while it is is doing so, so you want the smallest size injector possible.
Injecting is the controlled and variable period of time that fuel is flowing.
Closing takes time too, typically 0.5ms for the small injectors.
Resting is the time left over, and in a staged system when the resting time gets to short the EFI CPU moves up to the next (bigger) injector (or combination) because that takes less time in the Injection phase to get the fuel in there but a bigger injector dribbles to much fuel in the opening stage to be useful for good low speed running.

Instead of having the EFI CPU swapping from 38g to 80g as the rpm goes up. It is possible to have 38g and 38g so that when the 80g injector capacity is required because time is running out the system simply runs both 38g injectors together.

Instead of a single 248g high speed injector I have my 60+60 low speed plus 128 high speed arrangement for a total of 248g high speed injection. Having all three injectors firing together spreads the fuel mixing throughout the crankcase for hopefully a better homogenous mixture.

327725

My Ecotrons dual injector two stroke wiring harness came with two injector plugs. One for low speed the other for high speed. You can splice a second injector onto each plug lead if you want to, and it is what I have done.

I currently use 120g (two 60g injectors run in parallel, one in each B transfer port) for low speed and a single 128g injector in the crankcase for high speed. When time has run out to deliver enough fuel with the two 60g injectors run in parallel then the system halves the injector time required by bringing in the the 128g injector for a total of 248g of injector capacity (60 + 60 + 128 = 248g).

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My system uses low and high rpm injectors for a staged injector system. For low rpm there are two physical 60g injectors in the B transfer ports like this YZ250 cylinder has. My two 60g injectors are run together as one logical 120g injector for low rpm and the high rpm injector is a 128g unit in the crankcase. To aid mixing all my injectors are currently positioned to squirt against the air flow.

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When setting up the map, it is a really big help to have a wide band O2 sensor. On a two stroke the end of the expansion chamber seems the best place to put it. Unlike a four stroke which has them in the header. On a two stroke at the rear you get a good average mixture, in the two strokes header you get a confused reading from all the short circuiting fuel mixture.

Like others, I found the big problem with getting any EFI system going is not so much getting the fuel maps right, they are easy enough but all the options that come with EFI software, you have to sort through them and one wrongly selected option can take a while to find.

My work has all been aimed at outright racing power and very little to do with economy. But I have noticed that the orientation of the injectors and timing of the injection cycle can make a noticeable difference to the fuel demand. A carefully timed shot across the transfer airstream seemed to need less fuel than a general squirt into the crankcase, makes sense I guess.

And squirting the underside of the piston crown through a slot in the piston made very good low speed running but was not so great at max rpm. This was disappointing because I really wanted to use the fuel to cool the underside of the piston crown when making max power.

Good luck and please post your progress on here, I would love to be able to follow your projects success as you go along.

[TZ350]

Some links to YouTube clips of a couple of two stroke bikes modified for EFI.

Yamaha YZ250.

https://youtu.be/hOGZ5llowoU

https://youtu.be/UEQli7nuak4

https://youtu.be/1YG9ko8-Nwk

Kawasaki BigHorn.

https://youtu.be/eleqBGvOM4M

https://youtu.be/ifSEql1X4R0

https://youtu.be/CnIemdISKrM

[Peiter]

Hi TZ,

thanks for the extensive reply, I appreciate it!
Developing our own EFI CPU isn't the goal right now, we are more interested in an off the shelf system like the ecotrons.

From what I read on the ecotrons site, the max RPM of the kit is limited to 16.000.
Is this limitation due to the injection cpu, or does it only apply when one uses the same cpu also for ignition control? I had some mail conversation with ecotrons about this subject but I couldn't get it clear.

I will post regular updates on our project. At this moment, we are designing the 50 cc cylinder which we will first start using / developing on a reed valve tz 50 engine. The next step is then to design and machine rotary valve engine casings.
The design and development of the engine casings will likely be > 1 year of work while the cylinder will be ready in a few months.

Regards,

Peter

[husaberg]

Hi TZ,

thanks for the extensive reply, I appreciate it!
Developing our own EFI CPU isn't the goal right now, we are more interested in an off the shelf system like the ecotrons.

From what I read on the ecotrons site, the max RPM of the kit is limited to 16.000.
Is this limitation due to the injection cpu, or does it only apply when one uses the same cpu also for ignition control? I had some mail conversation with ecotrons about this subject but I couldn't get it clear.

I

Peter
https://www.kiwibiker.co.nz/forums/showthread.php/159112-Ecotrons-Engine-Management?p=1130989127#post1130989127

[TZ350]

I will post regular updates on our project. At this moment, we are designing the 50 cc cylinder which we will first start using / developing on a reed valve tz 50 engine. The next step is then to design and machine rotary valve engine casings.The design and development of the engine casings will likely be > 1 year of work while the cylinder will be ready in a few months.

Regards,

Peter

Hi Peter, I look forward to your posts.


From what I read on the Ecotrons site, the max RPM of the kit is limited to 16.000.
Is this limitation due to the injection cpu, or does it only apply when one uses the same cpu also for ignition control? I had some mail conversation with Ecotrons about this subject but I couldn't get it clear.

That is a good point, which is the limiting factor, Ignition or EFI or overheads from the combination? Unfortunately communication with Ecotrons is difficult, and clear communication with the help dept is all but impossible. Maybe it is a language barrier or clash of cultures thing. Or maybe they know their product and EFI so well they just can't understand why we don't.

Speedpro seemed to run into a upper rpm barrier of 16,000 rpm with his twin cylinder 4T running Ecotrons EFI and Ignition. He found Ecotrons help dept a challenge and has since started using a Link EFI CPU. He reports that Link here in NZ has been very helpful and understandable.

I am not sure how much experience Ecotrons has had with high speed two strokes as anything I can see 2T on their site refers to two stroke engines running at less than 10,000 rpm.

My Ecotrons system (same CPU different software to Speedpros) seems reliable to 13,000 rpm which is the physical breathing limit of my 2T engine.

My guess is you would be Ok to 16,000 rpm with a single cylinder 2T but after that "Time" is going to be a very limiting factor, it may pay to do some maths to figure out if the injection cycle can be completed in the time available at the rpm you are thinking of running. Typical pulse widths on my engine are 1.8 to 5 ms at lower rpm and typically around 3ms at max power (bigger injector).

I have heard of someone running a custom 2T EFI system where they alternated between two injectors so that the opening and closing-resting times were overlapping the next revolution and only the injection phase was on the current crank shaft revolution. Clever idea if you are desperately short of time.

[FastFred]

.

327853

Ok, I think I understand it now ... So, when the engine has got a hurry up, it becomes all about the diminishing amount of time to get the good stuff in there.

[Peiter]

I guess I was at first attracted to the complete packag" offered by ecotrons because this wouldn't require selecting an individual fuel pump and injectors and would be "plug and play".
However, the goal is to run up to 19.000 or preferably 20.0000 rpm.

Assuming 19.000 rpm, this results in 316 Hz, or 3.16 ms per full rotation. Taking the 1.5 ms of opening time and 0.5 ms of closing time as mentioned by TZ, this still leaves 1.16 ms of "tune" time in each rotation, right? Or am I making some mistake here?

We are thinking of using one small injector on the crankcase and one larger injector as a shower on the throttle body. Given the limited spare time in each cycle, I do think it will be critical to select the correct size of injector.

[husaberg]

I guess I was at first attracted to the complete packag" offered by ecotrons because this wouldn't require selecting an individual fuel pump and injectors and would be "plug and play".
However, the goal is to run up to 19.000 or preferably 20.0000 rpm.

Assuming 19.000 rpm, this results in 316 Hz, or 3.16 ms per full rotation. Taking the 1.5 ms of opening time and 0.5 ms of closing time as mentioned by TZ, this still leaves 1.16 ms of "tune" time in each rotation, right? Or am I making some mistake here?

We are thinking of using one small injector on the crankcase and one larger injector as a shower on the throttle body. Given the limited spare time in each cycle, I do think it will be critical to select the correct size of injector.

If you can somehow get the ecotrons to act as your single is actually a 2 cylinder ,yet is actually delivering fuel on alternate strokes you will have considerably more time available to deliver fuel at higher rpms.
Only thing is I have no idea if this is possible with the ecotrons.
Maybe something like a D type flip flop could work although there is likely far more modern better ways.
That said in the old days some four stroke turbos had continuous injection at high rpm
They used to call it 100% duty cycle.

[Peiter]

As I see it, the disadvantage of having 100% duty cycle at high rpm would be that we don't have any tuning range left other than the changing the the actual injector for a different flow.

Because we are starting from a blank page / scratch, we are not yet tied to a certain system or supplier. If the link atom or any other system offers better quality / performance then we can just as easily go for that kind of system. Finding the individual fuel pump and injectors would provide a slightly larger challenge in that case :).

As a side note however, we are already using a zeeltronic controllable ignition so the injection unit will only be controlling the injection, using the rpm from the zeeltronic as an input.

[TZ350]

I guess I was at first attracted to the complete packag" offered by ecotrons because this wouldn't require selecting an individual fuel pump and injectors and would be "plug and play".
However, the goal is to run up to 19.000 or preferably 20.0000 rpm.

Assuming 19.000 rpm, this results in 316 Hz, or 3.16 ms per full rotation. Taking the 1.5 ms of opening time and 0.5 ms of closing time as mentioned by TZ, this still leaves 1.16 ms of "tune" time in each rotation, right? Or am I making some mistake here?

We are thinking of using one small injector on the crankcase and one larger injector as a shower on the throttle body. Given the limited spare time in each cycle, I do think it will be critical to select the correct size of injector.

3.16ms cycle time. I would be willing to give that a go.

Other than the well known issues communicating with Ecotrons help dept which means you are basically on your own with something like a high revving 50cc 2T. But anyway that is what this thread is for, between use we probably can sort anything out. And I like everything else about what Ecotrons has to offer in the way of a complete system with plenty of affordable optional spare parts.

At the time of ordering I would get several spare injectors so I had a 30 - 38 - 60 - 128 and 246 on hand. Also in the advanced calibrations options there is an option for 1 - 2 or 3 injectors, it might be worth asking if there is a possibility for a three stage system. One of Ecotrons throttle body options has two injector in the one body. So you could easily experiment positioning.

On my engine the fuel needed at 7,000 rpm is pretty much the same as 12,000 but at 12 the time is shorter and that is the only reason I need a bigger second injector.

Ecotrons Record function allows you to graph (amongst many other things) total time available for injection and time used for injection. Makes it very easy to see if you can use a smaller injector or need a larger one. The trick is to have a few spare injectors on hand of different sizes.

In the end if the Ecotrons CPU does not handle 19,000 rpm then simply cut the wiring harness CPU plug off and wire in a Link Atom or something else. After all the other ends of the wires go to the right places like injectors, MAP sensor TPS etc.

I would start with an Ecotrons system. In the end it does not matter what system you use, it is do it yourself EFI from the ground up and that is what matters.

[husaberg]

As I see it, the disadvantage of having 100% duty cycle at high rpm would be that we don't have any tuning range left other than the changing the the actual injector for a different flow.

Because we are starting from a blank page / scratch, we are not yet tied to a certain system or supplier. If the link atom or any other system offers better quality / performance then we can just as easily go for that kind of system. Finding the individual fuel pump and injectors would provide a slightly larger challenge in that case :).

As a side note however, we are already using a zeeltronic controllable ignition so the injection unit will only be controlling the injection, using the rpm from the zeeltronic as an input.

note sure the actual capilities of the ecotrons vs the say micro/mega squirt
but the link ecu is clearly a more sophisicated peice of kit

ps tz have you seen this one

https://www.youtube.com/watch?v=_aAfptmI4jU
http://www.dotheton.com/forum/index.php?topic=12787.180

first start no tuning

https://www.youtube.com/watch?v=A7fONUsJQD4

[speedpro]

Just go with the Ecotrons system. To get going it is a very good deal. You just have to be aware that it is limited. The main limit is the revs. By default the 4 stroke systems are limited to 14,000rpm. You cannot even enter a higher value.
Their fuel pressure regulators are junk. Do yourself a favour and get a good quality regulator, AND, monitor fuel pressure. Don't expect much help from the help department.

[TZ350]

327892

Blue - RPM, Yellow - maximum injection time, Green - small injector, Red - big injector

Starts with the small injector, swaps to the big injector then runs both at the same time.

[Drew]

As I see it, the disadvantage of having 100% duty cycle at high rpm would be that we don't have any tuning range left other than the changing the the actual injector for a different flow.

Because we are starting from a blank page / scratch, we are not yet tied to a certain system or supplier. If the link atom or any other system offers better quality / performance then we can just as easily go for that kind of system. Finding the individual fuel pump and injectors would provide a slightly larger challenge in that case :).

As a side note however, we are already using a zeeltronic controllable ignition so the injection unit will only be controlling the injection, using the rpm from the zeeltronic as an input.
Adjust the fuel pressure.

[FastFred]

Adjust the fuel pressure.

It is what some cars do, 5 bar starting and warm up, 3 bar normal running.

[Cheesy]

I guess I was at first attracted to the complete packag" offered by ecotrons because this wouldn't require selecting an individual fuel pump and injectors and would be "plug and play".
However, the goal is to run up to 19.000 or preferably 20.0000 rpm.

Assuming 19.000 rpm, this results in 316 Hz, or 3.16 ms per full rotation. Taking the 1.5 ms of opening time and 0.5 ms of closing time as mentioned by TZ, this still leaves 1.16 ms of "tune" time in each rotation, right? Or am I making some mistake here?

We are thinking of using one small injector on the crankcase and one larger injector as a shower on the throttle body. Given the limited spare time in each cycle, I do think it will be critical to select the correct size of injector.

If you plan on using a shower injector into the throttle body, it will probably make very little difference if it is timed to the engine cycle or not

[Peiter]

I agree but there should always be some spare time during a cycle, because otherwise my only option to add more fuel would be increasing pressure or the injector.

I have emailed ecotrons last week but they haven't reacted yet.

In the mean time, two images of the cylinder that I'm drawing. Next up is the outer/top cover as a shell over my current part.

328052328053

[TZ350]

328087

It looks like the low speed injector is not true to size. Because the WO2 trace gets progressively leaner until the system swaps to the high speed injector. The injectors delivery is smaller than the EFI CPU thinks it is. Thinking its bigger than it is the CPU turns the injector on for less time than it should so the WO2 shows a progressively leaner mixture. Easy fix, tell the CPU a smaller guesstimated value for the injector.

The map (and engines delivery ratio) is flat here so the WO2 trace should be flat too. At the swap over point the low and high speed injector WO2 trace should line up without that big step. I can jiggle the sizing in the software until I get it right but measuring all the injectors outputs first would be a bit of work setting up but a good idea.

[husaberg]

328087

It looks like the low speed injector is not true to size. Because the WO2 trace gets progressively leaner until the system swaps to the high speed injector. The injectors delivery is smaller than the EFI CPU thinks it is. Thinking its bigger than it is the CPU turns the injector on for less time than it should so the WO2 shows a progressively leaner mixture. Easy fix, tell the CPU a smaller guesstimated value for the injector.

The map (and engines delivery ratio) is flat here so the WO2 trace should be flat too. At the swap over point the low and high speed injector WO2 trace should line up without that big step. I can jiggle the sizing in the software until I get it right but measuring all the injectors outputs first would be a bit of work setting up but a good idea.

Back years ago they used to flow test and flow map injectors and then match injectors. Not all were created equal.

[F5 Dave]

Hard to find anyone to do that in nz. I had to send some to factory pro in us for the 675. Only really an issue when several cylinders

[husaberg]

Hard to find anyone to do that in nz. I had to send some to factory pro in us for the 675. Only really an issue when several cylinders

http://www.nzefi.com/fuel-injector-servicing/
http://www.injectortech.co.nz/
http://dieselandturbo.co.nz/petrol-fuel-injection/
http://www.msel.co.nz/Blog-1/Find-Out-Exactly-What-Your-Injectors-Flow
I was meaning more to map excactly what they flowed
just down the road from You Rob
http://www.msel.co.nz/Contact-information

[F5 Dave]

Well the 2nd one only cleans. As did the other places I found. The ones you've post obviously must have started up business in the last few months. Or they were hiding. Or. Didn't look very well. Meh, they're done now. Helped free shipping for 2 sets from eBayto make a match for 3.

[husaberg]

Well the 2nd one only cleans. As did the other places I found. The ones you've post obviously must have started up business in the last few months. Or they were hiding. Or. Didn't look very well. Meh, they're done now. Helped free shipping for 2 sets from eBayto make a match for 3.

LOL
Err second one blurb

Welcome to InjectorTech!
The service we provide at InjectorTech is the cleaning, diagnosing faults and flow testing of petrol injectors. We have installed the very latest technology in injector servicing

[TZ350]

http://www.msel.co.nz/Blog-1/Find-Out-Exactly-What-Your-Injectors-Flow
I was meaning more to map excactly what they flowed. just down the road from You Rob
http://www.msel.co.nz/Contact-information

Great, thanks for that.

[husaberg]

Great, thanks for that.

The magic of Google:clap:

[TZ350]

Hi All,
Thought I’d drop by to share the findings of my YZ250 EFI project. It has a 2009 CRF450R 50mm throttle body, 3D printed polyurethane throttle boot to a Boyesen RAD valve. Fuel system is returnless with a Walbro GSL-414 pump controlled by a Madhu PWM pump controller/pressure sensor. Fuel filter is a Sytec mini bullet. Injector is the CRF450R 12 hole injector (440cc/min @ 4 bar). It’s controlled with a Microsquirt V3 running MSextra code, triggered by a 20-1 tooth wheel welded to the ignition rotor and a crank sensor from a YFM350.

It’s tuned in Alpha-N strategy (TPS vs. RPM table), with barometric pressure sensor and intake air temp sensor for compensation. It uses a Wideband O2 and logs either EGT or Fuel pressure.
First start was about a month ago, have put 3 tanks of fuel through it so far. Most of the tuning has been automatic based on AFR targets, except idle, light throttle and overrun where it needs to be tuned manually. 50mm throttle feels just as linear as the 38mm carb. I haven’t used any accel pump fuelling yet, so I’m hoping that will sharpen the throttle up a bit more.

Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value. I tried tuning a ledge into the fuel map, it was better than before but still hit and miss, fast roll on was ok, slow roll on or steady part throttle would still flood.
Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isn’t firing, due to the exhaust vacuum after blowdown pulling charge through the engine.
Therefore the fuel required for a cycle can be predicted by whether or not the engine fired on the previous cycle, in addition to engine speed and throttle position.
So my solution is to check whether the cylinder has fired, then adjust the fuel table for the next cycle. The throttle body MAP sensor is connected to the exhaust port and samples the pressure during blowdown. I’ve set up a 2nd fuel table in the ECU with a multiplier for when the pressure is above a threshold, corresponding to the cylinder firing. When the exhaust pressure is high, the main fuel table is unchanged, when low, it is reduced by 50% (will need to be dialled in for various RPM, but seems to work so far). The main fuel table is tuned with the wideband when the motor is firing, then extrapolated into the non-firing low throttle/overrun area. On closing the throttle, once the motor stops firing, fuel flow drops to match the airflow, so the motor doesn’t flood. On opening the throttle, the mixture is correct to initiate firing, then after the first fire fuel flow goes back to the main table value.

I think with some tuning I should be able to get the transition pretty much seamless. At the moment I'm working on getting the fuel table just right around the transition area, then I'll work on the switch threshold and multiplier values. That said, it's pretty decent already, but I'm a perfectionist.

Nathan

https://www.youtube.com/watch?v=4Zsz26QmfAU

328790
328789
328791
328792
328793


I like your approach very much Nathan. But looking at your third picture, I wonder how much radiator heat will be picked up by the fuel. Some fuel components have a boiling point around 50° C ....




Throttle transition at high rpm has been the main tuning issue. When closing and reopening the throttle, the motor would flood and not refire until the revs dropped, so I figured the airflow must drop off at some throttle value.

Then I figured that the airflow wasn't just related to the throttle, but when the engine is firing, the airflow is significantly higher than when it isn’t firing, due to the exhaust vacuum after blowdown pulling charge through the engine.Great stuff, TeeZee will be very interested.My thought too. Waiting for TeeZee now.

Yes, very interested. Thanks Nathan, for the great idea of using a MAP sensor to measure the pressure changes in the exhaust system so as to see the changes in bulk air flow through the engine, I wish I had thought of that ages ago.



Overun over fueling, Cagiva had the same issue. Yours is a bloody neat set up though.

https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301602
https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301601
https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301600
https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301599
https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301598
https://www.kiwibiker.co.nz/forums/album.php?albumid=4842&attachmentid=301597

The Cagiva used to keep pumping in fuel on over run, then bog with its rich mixture and then chime in with a potential highside causing burst, when the unburned fuel finally cleared out of the crankcase.
Pumper carbs can do the same thing, not an issue on karts as they tend to keep on the gas.
I think What you have done is you have compensated for lower airflow and incomplete combustion on over-run, which was creating a richer mixture in the crankcase, which is what a conventional vacuum metered carb does.I found with my system it would never clear once it bogged, just 100% dead until the revs dropped. They must have been using some method of clearing it.
I guess that's why injected snowmobiles and boats don't have the issue, as soon as the throttle is cut the revs drop.
Nice article on the Cagiva too, I hadn't seen that one.



I found with my system it would never clear once it bogged, just 100% dead until the revs dropped. Exactly my problem too.


Same problem everyone else, from Cagiva through to Suter last year at the IOM the longer time at full throttle the worse it will be.That overlay from the ECU on the video is uber cool


Measuring the blowdown pressure pulse rather than the negative (since they should be proportional) gives you a head start on getting the fuel in. I have the pressure sample window set to 140-170° ATDC. The peak moves with RPM, because of the delay along the hose to the MAP sensor, so best to keep it as short and close to the port opening as possible. I have the injection start 10° after the sample window, so the latest pressure value is used to calculate the injector pulsewidth.

I suspect the pulses develop to full strength over a few cycles, as the return wave strengthens the combustion, so probably no need to get all the fuel in on that first cycle after measurement.

I am measuring through the powervalve vent, so my pressure values are only indicative for firing or not. With a proper exhaust port measurement you could adjust fuelling based on the pressure rather than just firing/not-firing..


Not likely; the 125 cc KTM GP-bike already had an injector in the crankcase that injected through a port below the exhaust port.
They used it instead of a powerjet and it would only have been logical to use the same setup for full EFI.
328804 328805 328806

[husaberg]

http://power4flight.com/wp-content/uploads/2014/08/EFIAutoTuning.pdf
pg 7

 Overrun: defined as high RPM and low throttle (or a "light" load). This case should only be encountered in transient conditions. MBT is used to maximize combustion stability. The light load line starts at 20% throttle and 4000 RPM. It extends through 40% throttle and 7000 RPM. Any condition that is a lower throttle than this line is considered light.

[TZ350]

I have tried a few different places for injectors, some places seemed to be better than others.

329574

This injector in the bellmouth seemed to be the worst of the different positions I have tried.

329570 ... 329572

This arrangement seemed the best with the central low speed injector squirting through a slot into the underside of the piston. With the injection cycle set to end 180 deg ATDC. I guess the action of the piston produced a good homogeneous mixture for low speed and small throttle running.

The two high speed injectors, one each side run together as one logical injector and fire horizontally across the entrance to the B and A ports.

This system worked best.

329571

The current setup is an injector firing vertically down in each B port and one horizontally across the crankcase with the injection stream aimed directly into the incoming inlet air stream.

329573

Method-1 ... The obvious thing is to have the low speed/load injector (1x128 g/min) smaller than the high speed/load injector (2x128 g/min) for a total of 256 g/min for high speed/load injection. But this does not work well because there is a hard cutover from fueling in one area of the crankcase volume to an entirely different place and this seems to leave a bubble of fuelless air that is then suddenly swept into the cylinder creating a blip in the engine's output. Green RPM line dips as injector one stops and injector two takes over.

329575

Method-2 ... A more successful approach has been to have the low speed/load injector (1x128 g/min) slightly bigger than the high speed/load injector (2x60 g/min). That way the low speed injector never stops and the high speed injector comes and goes as required to supplement the low speed unit (1x128 plus 2x60 for a total of 248 g/min at full load).

This way there is no discontinuity in mixture strength. The Green RPM line is smooth. Low speed/load injector left red line, high speed/load injector yellow line coming in as required to supplement the low speed one.

A high RPM 2T that rev,s past 10k rpm must have staged injection because an injector big enough for high load high speed is too big for low speed low load. So staged injectors are required. Lower rpm 2T's can get away with a single injector.

Method-1 ... (1x128 g/min) .or. (2x128 g/min) for 256 g/min high load injection capacity.
Method-2 ... (1x128 g/min) plus (2x60 g/min) for 248 g/min high load injection capacity.

So both methods give much the same injection capacity but method-2 gives a much better transition.

[Drew]

Stop fucking about and go straight into the chamber would ya.

[FastFred]

Stop fucking about and go straight into the chamber would ya.

Sounds like that would be the story, but is int a 2T with direct injection time limited to 10,000 rpm or less and the injection pressures required much higher. ... :scratch: ...

[Drew]

Sounds like that would be the story, but is int a 2T with direct injection time limited to 10,000 rpm or less and the injection pressures required much higher. ... :scratch: ...
Hmmmm. I'm not convinced it makes any difference in regards to time you've got for squirt.

[TZ350]

Hmmmm. I'm not convinced it makes any difference in regards to time you've got for squirt.

Not sure if Frits answers your doubts, but time is everything and it seems to become increasingly in short supply after 9-10,000 rpm.


At WOT, injection has to start much earlier in order to create a good mixture. The latest version, the E-TEC 850, even falls back on a couple of additional indirect injectors in order to counter this problem.
329362

It takes time for the injector to open, deliver fuel, close and rest.

And a very significant time problem is the time it actually takes for wet fuel to evaporate and form a homogenous mixture that you can set fire too.

Direct cylinder injection after exhaust port closure has at best 90 deg or a quarter of the time of indirect crankcase injection.

Direct injection after BDC and while the exhaust is still open gives you half the time at best of indirect crankcase injection and if you are willing to risk having raw fuel short circuit directly out the exhaust, direct cylinder injection has at best 3/4 of the time of crankcase injection. Crankcase injection can obviously be for the full 360 deg of crank rotation.

Time is short enough after 10,000 rpm to get everything done even when you have the full 360 deg of crank rotation to work with and cutting that time in half or into a quarter is probably less likely to workout well.

As well as time, pressure is another issue. Trying to inject into 10 bar cylinder compression pressure with 3 bar fuel pressure is just not going to happen. So at some point on the compression stroke injection is not going to be possible.

With direct cylinder injection and subtracting out the time lost to fuel homogenous issues, compression pressure, ignition advance, combustion and power stroke to exhaust port opening you have very little time left to work with compared to indirect injection.

Indirect Injection time possible ='s 100% of the time available for 360 deg's of crank rotation.

Direct Cylinder Injection time possible is obviously much less.

[Drew]

It doesn't need to start after the exhaust closes though. Some can go down the spout and get shoved back in by the returning pulse the same as it is with the system you have now. No?

But with enough volume, time lessens. So three in the head.

Good for cooling too.

[TZ350]

It doesn't need to start after the exhaust closes though.

True, how early would you start and where would you end the injection cycle so you still have enough time for the wet fuel to evaporate and become a homogenous mixture before ignition.

[Drew]

True, how early would you start and where would you end the injection cycle so you still have enough time for the wet fuel to evaporate and become a homogenous mixture before ignition.

I'd start spraying as soon as the inlet ports closed or a little before. If it's hitting the top of the piston it's gonna mist up real nice I would have thought. That being my underatanding of why direct inject was more efficient.

[TZ350]

Yes, reportedly works well at low speed <10k rpm, maybe you could put some numbers together to see how likely it is at 13k rpm.

[Drew]

No thanks, it's not my bag.

[FastFred]

I'd start spraying as soon as the inlet ports closed or a little before. If it's hitting the top of the piston it's gonna mist up real nice I would have thought. That being my understanding of why direct inject was more efficient.


Yes, reportedly works well at low speed <10k rpm, maybe you could put some numbers together to see how likely it is at 13k rpm.


No thanks, it's not my bag.

Drew faith based intuition is great for giving you a direction to look in and being able to put (rough) numbers to something like TeeZee does can tell you if you are on the right track or not. Numbers can save you from a lot of wasted time.

Time at 13k rpm = 4.6ms for a complete 360 deg crank revolution.

Transfer opening to closing 130 deg. 1.7ms.

From exhaust port opening to closing 200 deg. 2.6ms

From exhaust closing to ignition. (with ignition timing 18 deg BTDC). 72 deg. 0.8ms.

Pressure in the cylinder ATDC greater than the 3 bar fuel injection pressure 90 deg, 1.2ms.

So somewhere between 1.7 and 2.6ms for injection, 0.8ms for fuel homogenization.

2-3ms required to open and close the injector 2-3ms required to deliver the fuel another 2-3ms or so to homogenize it.

Total time required:- 6-9ms

Drew, is there enough time to get everything done? I am picking not, and I am picking TeeZee doesn't think so either.

[TZ350]

With EFI, "Time" is King. :niceone:

[TZ350]

329951

Because there is a period between 6 to 7,000 rpm of violent oscillation just before coming onto the pipe. Even cranking the power valve down to ridiculous amounts did not help.

Red line TPS
Blue line O2 sensor
Brown line Small injector
Yellow big injector
Top Green line is RPM

Looks like you have a fair bit of lash in the drivetrain with the engine speed jumping around like that. At 15% throttle it looks like the switching between the small and big injector is causing the misfire, possibly injector settings are a bit squif and when it switches over it jumps richer or leaner. Is it just a straight RPM switchpoint with no hysteresis?
At 50% throttle it looks like it's going too rich as the revs climb and pulsewidth goes up, then stops firing, revs fall, pulsewidth drops, then it kicks on again. I think the problem is in fuel delivery not gas dynamics. Guessing it doesn't do it with the carb? Food for thought.

Also there is a big lambda delay on these things off the pipe and it always swings lean when misfiring. Is the motor on the rich limit/four stroking? Your lambda values look ok, but they can appear lean when air is short circuiting the motor. My motor has a 'rich' point between 4500-5500rpm, 50% throttle and up. I think it's the anti-resonance point of the pipe. Shows the same 12.6:1 AFR as other points but its on the verge of four stroking, heaps of blue smoke, similar to how 10.8:1 behaves (which is about the rich 4-stroking limit on mine when on the pipe). So i've tuned that area to be about 1.5 points leaner. I am yet to do a plug chop at that point to check, I'm yet to do any plug chops actually, luckily the YZ isn't too picky on mixtures.

I put some hours on my thing on the weekend, did about 150km around the city and mountains with the new fuel system. It was running a fair bit richer for the same fuel pressure, so the pressure at the injector must be more constant. Also the VE table is starting to look how I would expect, a lot more natural and smooth, apart from the weird anti-resonance peak. Maximum injector duty cycle of 80% at 9200rpm, full throttle, 145km/h uphill. It used to do 150km/h with the carb on the flat, but I haven't leaned the EFI out past peak yet. Next on the list is to get the target AFR table right to maximise power, will probably do a bunch of plug chops to see what the motor likes, maybe hit up the dyno.

There is a lot to think about here, I think you are definitely on the money. Very encouraging to hear about you success's with the YZ.

[TZ350]

Took the bike for another ride last night. Leaned it out a fair bit in the high load areas, a little in the cruise range, and a bit past peak rpm. Made the bike very happy! Was going to be a short one but ended up cruising around the streets for about half an hour because it was running so well, bike never missed a beat. 'Lean' cruise is a funny feeling, it's very smooth, like a scooter, then when you open the throttle it just rolls into normal YZ250 in every way.
329972

The VE table ended up looking like this, load areas tuned by wideband lambda feedback.
329979

This is the exhaust pressure system in action. Just before the cursor position, I blipped the throttle to 20% and the motor didn't respond (no exhaust pulse = no fire), that's the area I need to work on the most, probably a bit rich at closed throttle at that RPM, lambda offers no useful feedback so it has to be tuned by feel. After the cursor, when opening the throttle to 20% for a little longer, the motor has time to clear, then the injector pulsewidth more or less follows the exhaust pressure. You can see it four-strokes a bit then runs clean. Then opening the throttle to 15% goes into constant light throttle four-stroking, again, fuel following the exhaust pulses.
329973

Thanks........

[TZ350]

.

Injector Position

331035 331038

Central injector fires through a slot into the underside of the piston.

My favourite low speed injector position has been to fire under the piston. This seems to help enormously with fuel homogenization at lower and off pipe engine speeds.

331036

My least favorite and less successful position has been to inject directly across the crankcase into the oncoming inlet air stream. During periods of air flow reversion fuel gets blown out the inlet. And also at higher speed low throttle there is not enough time for a small squirt of fuel to travel right across the crankcase for even fuel distribution.

331037

Looking at a piston positioned slightly below transfer port opening the two clean spots at the edges look to me like marks left from air/fuel short circuiting from the A ports and washing the carbon away.

When I showed this to Flettner and asked about injector positioning. He suggested an injector in each of the A and B ports.

331033

Flettner suggested the B port injectors should handle the low speed fuel demand leaving only fresh air short circuiting from the A ports.

And any short circuiting is most likely at lower engine speeds before the reverse pressure wave action from the pipe blocks the exhaust port as the motor gets up into the power band.

At higher engine speeds when the motor is up on the pipe, then have the A port injectors chime in. That way with fuel injected into all four A and B ports the mixture should be pretty homogeneous. Flettner's idea sounds better than what I have been doing which is trying to combine two purely air streams from the A ports with two overly rich streams from the B ports and have them properly mix together in the cylinder.

As for problems coming back on the throttle after shutting off for a corner Nath88 suggested that at less than 20% throttle the EFI ECU needs to be able to differentiate between when the engine is firing and the pipe is sucking and creating a higher bulk air transfer through the motor and therefor fuel demand verses when the wave action in the pipe has totally collapsed and much less fuel is required.

The Alpha-N map can’t do this by itself, there needs to be some way for the ECU to tell if the engine is firing and the pipe sucking or not. Nath88 suggested measuring the return positive pressure pulse at the exhaust port. It is a great idea and I like it but unfortunately, I have not found a way to get my Ecotrons EFI software to do that.

Flettner suggested measuring the internal pipe pressure at the dwell section in the middle of the pipe. He pointed out that the pressure must drop when the wave action collapses and that by using a VE table below 20% throttle/load and Alpha-N above that I might be able to train the ECU to recognize when the motor is firing and wave action in the pipe is increasing demand for fuel.

I like Flettners idea of low speed injectors in the B ports and secondary injectors in the A ports that chime in when the fuel demand under full power/load requires all four injectors.

331034

I have ordered more parts from Ecotrons and my next challenge is a lack of room and to figure out how to fit a secondary injector close to the power valve actuator.

When I followed Nath88's very clever idea about using the return pressure wave at the exhaust port to see when the motor was firing. I ran into a problem, my ECU software averaged the low suction pulse and high plugging pulse and arrived at a lower average for on power open throttle compared to closed throttle. Makes sense when you think about it but I could not figure out how to get the ECU to make sense of it. Basically it needed to reduce fuel when the average pressure was higher and increase fuel when it was lower. This is opposite to the way EFI ECU's think.

In the mean time I am going to get this Beast going again and try Flettners idea and see what sort of average pressures are in the dwell mid section of the pipe and if the EFI ECU can make sense of them.

[TZ350]

What we need now are injectors that are small enough and fast enough.

I have personally run an Ecotrons small injector at 13,000 rpm in my 125cc two stroke engine ... http://www.ecotrons.com/components/fuel-injectors/



When I followed Nath88's very clever idea about using the return pressure wave at the exhaust port to see when the motor was firing. I ran into a problem, my ECU software averaged the low suction pulse and high plugging pulse and arrived at a lower average for on power open throttle compared to closed throttle. Makes sense when you think about it but I could not figure out how to get the ECU to make sense of it. Basically it needed to reduce fuel when the average pressure was higher and increase fuel when it was lower. This is opposite to the way EFI ECU's think.
That's exactly the problem I'm having now... I've been experimenting with measuring the crankcase pressure instead of exhaust, just after transfers open. Under 25% throttle once on the pipe (7000 up) the pressure is lower than at 0% throttle... then over 25% the pressure starts going up. Which makes sense, the scavenge effect of the pipe drawing against the mostly closed throttle. But as you said, no good for a normal 4 stroke style ECU, it expects a linear input. I should put up some graphs of the data collected. Perhaps if you sampled the pressure before and after the transfers open then take the difference. The ability to write the code specifically for the engine is where KTM has a massive advantage.

At the moment I'm working on modifying the ECU code to capture the highest peak of the exhaust pulse as the port opens. I think this will be a good indicator of how much wave energy has gone into the pipe. So far the best results have been with the exhaust pressure at the powervalve vent. The PV housing was acting as a damper, smoothing the pressure pulse so the ECU could catch the peak easily, signal was a bit too smooth so I'm trying other methods, trying to nail an analog carb feel on throttle transitions. If the code mods don't work out (I'm no programmer), back up plan is to use a 'precision peak hold' circuit on the map sensor, then using the ignition output to reset the circuit at the start of each cycle. You could implement this on your ECU easily enough.



At the moment I'm working on modifying the ECU code to capture the highest peak of the exhaust pulse as the port opens. I think this will be a good indicator of how much wave energy has gone into the pipe.
Another option would be to look at the highest peak of the exhaust pulse after BDC, i.e. the return pulse. That will be an equally good indicator of how much wave energy has gone into the pipe, and it offers the additional advantage of knowing when this return pulse arrives back at the cylinder. If it's too early, lower the EGT by advancing the ignition timing; if it's too late, retard the ignition timing. That way you'll have a truly intelligent ignition and you can forget about EGT.

A lower compression ratio forcibly yields a lower expansion ratio; less combustion energy is converted into torque by the time the exhaust opens and more of this energy remains in the exhaust gas in the form of higher pressure and higher temperature. This remaining energy drives the exhaust pulses, improving cylinder filling for the next combustion event, and the next and the next.... This way a lower compression ratio can lead to higher power.

The lower comp ratio also made engines less sensitive to piston ring groove wear and ignition spark strength, and it helped overrev, so the bikes became easier to ride.
At the end of the lead-area the Aprilias had a compression ratio of 19,5. When lead was banned, this ratio was initially reduced to 14, after which it was gradually raised again. My personal preference would be to try even lower ratios in order to feed the pipe with even more energy.

[TZ350]

331122

EFI CR250 https://youtu.be/VlHyRcmlLgU

http://www.supermototecnica.com/2015/09/10/sviluppi-del-sistema-iniezione-diretta-indiretta-due-tempi/

331123

[TZ350]

Links to a whole bunch of EFI projects. Mostly amature home tuners, and all great work.

EFI Kawasaki Bighorn on the dyno https://youtu.be/ifSEql1X4R0
EFI Kawasaki Bighorn Trail ride 1 https://youtu.be/eleqBGvOM4M
EFI Kawasaki Bighorn Trail Ride 2 https://youtu.be/CnIemdISKrM
EFI Kawasaki Bighorn VMX https://youtu.be/v8i6ps0PdVI

Maramarua classic forest trail ride https://youtu.be/ZqzOgOJuJ1E

EFI YZ dyno run https://youtu.be/UEQli7nuak4
EFI YZ250 look around and first start up https://youtu.be/hOGZ5llowoU
EFI YZ250 trail ride 1 https://youtu.be/1YG9ko8-Nwk

Nath88?
EFI first start up https://youtu.be/wIRF3VJUqBk
EFI ride around the block https://youtu.be/4Zsz26QmfAU

CVT EFI NOS and everything else https://youtu.be/A9d-atuQO7Y
EFI and Turbo Snow Cat https://youtu.be/U1uz7gdS-cA
SeeDoo Etec https://youtu.be/LhNHcy9si5o

1975 Suzuki GT250 road bike fuel injected start up https://youtu.be/A7fONUsJQD4
1975 Suzuki GT250 road bike fuel injected road test https://youtu.be/BePHcg5dNjw

Fuel injected 1971 Yamaha R5 https://youtu.be/qzVHgHJ9PWI

Athena Direct Injection https://youtu.be/h-F_IndOm5I

BRC 250 EFI kart engine https://youtu.be/dNat9ZwWbq8
BRC 250 EFI kart engine https://youtu.be/Kfx61bUOznc

Racing EFI Vespa https://youtu.be/_sjx2i4xFlY

EFI Banshee first start https://youtu.be/e1WHVVT6d9c
EFI Banshee run https://youtu.be/eznxX_ndpII

Direct injection https://youtu.be/IpjWi-0qTJg

Will direct injection DI save two strokes https://youtu.be/ql2-wW0LuWY

Orbital direct injection https://youtu.be/fIoB0zTeUAY

EFI Dragbike Thailand https://youtu.be/VB6Q_fQQ_PY

Mega Squirt YZ125 https://youtu.be/Di8FuHApLKA

Aprilia RSi 125 EFI Part 1 https://youtu.be/S1xvr_VXzx4
Aprilia RSi 125 EFI Part 2 https://youtu.be/j5FOUn7V3nc
Aprilia RSi 125 EFI Part 3 https://youtu.be/WBaiMJb6ntY
Aprilia RSi 125 EFI Part 4 https://youtu.be/pZl5KPwvm0s

EFI 125 kart engine https://youtu.be/4D8WRjDxan0
EFI 125 kart engine https://youtu.be/b1YbPdw00Ww
EFI 125 kart engine https://youtu.be/r5ljaDdaH_o
EFI 125 kart engine https://youtu.be/uexMJbtyZdU
EFI 125 kart engine https://youtu.be/uzbSsYh8Z9w
EFI 125 kart engine https://youtu.be/XIcX9-GsMGQ
Fuel injected Kart https://youtu.be/R5_KlcefQ8k

2017 KTM dyno https://youtu.be/8g0uSIisMtI
2017 KTM demo ride https://youtu.be/nf1tfdUtjJI

EFI CR250 https://youtu.be/VlHyRcmlLgU http://www.supermototecnica.<wbr>com/2015/09/10/sviluppi-del-<wbr>sistema-iniezione-diretta-<wbr>indiretta-due-tempi/ (http://www.supermototecnica.com/2015/09/10/sviluppi-del-sistema-iniezione-diretta-indiretta-due-tempi/)

EFI YZR500 https://youtu.be/tNAtmKzqo9A

EFI CR500 https://youtu.be/BskSxMoQrwA

2T Nitro Engine visible combustion https://youtu.be/aO5Qkzlo2Kw
2T visible combustion https://youtu.be/G7PSec7RjRw
More 2T Visible combustion https://youtu.be/BrWpF6YiSDs

Fuel Burn in a side valve 4T https://youtu.be/jdW1t8r8qYc
4T Visible fuel burn https://youtu.be/31mtOdHGbB4

[TZ350]

Looks like High Gain Tuning may have solved the issues that are holding me back and sell a kit for DIY two stroke EFI.

http://twostrokemotocross.com/articles.php?id=336

[F5 Dave]

Careful. This guy showed up on the RZ forums with a hiss and a roar, and lots of self promotion in a wayonly Americans seem comfortable with,. . . got upset when people asked questions (how dare they) and then disappeared never to be heard of. Note article 2011.

[Claus290373]

Hello
Anyone know why I get this message when I want. To try
Auto tune " ecocal can't find the auto tune table
In the al2 file ?

[F5 Dave]

al1 stack over flow.

Resynchronise the initial constituants.

[Claus290373]

al1 stack over flow.

Resynchronise the initial constituants.


Hello anyone know why I get this message when I try to
open auto tune " ecocal can't find the auto tune
table in the a2l file ?
And what to do ?
Thx claus

[TZ350]

Applying some quite basic arithmetic, 13,000 rpm on a two stroke, equals roughly 26,000 rpm on a 4 stroke as regards injector cycles. Maybe that goes some way to help explaining the anomaly.

Absolutely


I'm also very interested to hear more of your findings in your NSR250 porting. You actually lost power by opening up the ears of the exhaust port? You're either transfer limited, or major short circuit going on A transfers to ex port. You may find it beneficial to "bowl" out ex port right after window.

Yes my first effort at porting the NSR cylinder lost power. And I think you are right about the reasons. I tried leveling the top of the exhaust port off by eye but totally stuffed up the exhaust port timing, got something like Ex opens 74 ATDC and to get the timing anywhere sensible I trimmed 2mm of the bottom of the barrel. The Ex was then 78.5 atdc and trans 122. To get the trans back to 113 I angled the A's up at 25 deg and the B's at 15 but the whole thing was a shambles.

So I started again.

332289


TZ350, we rev 250 4 strokes to 15,000rpm all day with a single injector in the throttle body. I'm comparing apples to oranges I know, but still... was shocked to think you need 3 injectors for 13k.

There are actually only two "logical" injectors, one big one small. The two "physical" injectors in the B ports are there for symmetry of fuel distribution and are fired together as one Logical injector. I use three physical 124g/min injectors but the EFI CPU sees only two logical injectors, a 124g/min slow speed injector and one 248g/min high speed injector.

But it is not about injector size but time available to get the injecting done. If you only have half the time, then you need an injector twice the size to get the job done. And you need a small one for tune-ability when there is plenty of time like <9k 2T rpm (equivalent to 18k 4T rpm) and a much bigger one to deliver much the same amount of fuel when time is getting short like above 10k.

The reason you can't use the big injector for slow running is because an injector must be turned on for a minimum amount of time to get it completely open and controllable. And a big injector just spills to much uncontrolled fuel while it is opening for idling speeds and small throttle opening.

15,000 4T maxed out rpm "Time" for an injection cycle is just about where my 2T is starting to come on the pipe and get going. A 4T has twice as much time to get things done so only needs an injector half the size of a 2T, ie something about the size of my slow running injector.

It is "Time" not injector size that is the real issue with EFI.


... a single injector in the throttle body.

Another issue with 2T EFI and throttle body injection is that unlike a carburetor which adds fuel to the air stream all the time, regardless of whether the air is being sucked in or blown back out of the crankcase ie fuel standoff.

A fuel injector squirts fuel in discreet blobs. And is just as likely to add all the fuel to the air stream as its blown back out as it is to the air stream being sucked in. So there could easily be rpm patches where you could wind up with little fuel at all in the crankcase.

This is less of a problem with transfer port injection. Where the bulk of the fuel is concentrated in the transfer duct and not the inlet tract where it can be more easily ejected. And will be one of the reasons why 2T EFI can show improved fuel efficiency over a carburetor.

And another reason for injecting into the B transfers is that the bulk of charge short circuiting happens from the A ports and if there is little fuel in the short circuiting air then the motor is cleaner and more fuel efficient. Another win over the carburetor which would have loaded all the crankcase air with fuel. With a carburetor all blow back and short circuiting air loses fuel and pollutes the environment, with 2T EFI not so much.

[TZ350]

Because someone asked.

There are three physical injectors but there are actually only two "logical" injectors, one big one small.

The two "physical" injectors in the B ports are there for symmetry of fuel distribution and are fired together as one Logical injector.

I use three physical 124g/min injectors but the EFI CPU sees only two logical injectors, a 124g/min slow speed injector and one 248g/min high speed injector.

In broad terms, because there is much the same amount of air consumed per revolution. Both 124 and 248 Logical injectors each deliver much the same amount of fuel per revolution.

332298

Both 124 and 248 injectors deliver much the same amount of fuel per revolution.

Because the 124g/min injector at lower speed has 10ms to do the job.

And the 248g/min injector at higher speed only has 5ms to do the job so needs to be twice as big.

Time available dictates the relative injector sizes.

[Drew]

Because someone asked.

There are three physical injectors but there are actually only two "logical" injectors, one big one small.

The two "physical" injectors in the B ports are there for symmetry of fuel distribution and are fired together as one Logical injector.

I use three physical 124g/min injectors but the EFI CPU sees only two logical injectors, a 124g/min slow speed injector and one 248g/min high speed injector.

In broad terms, because there is much the same amount of air consumed per revolution. Both 124 and 248 Logical injectors each deliver much the same amount of fuel per revolution.

332298

Both 124 and 248 injectors deliver much the same amount of fuel per revolution.

Because the 124g/min injector at lower speed has 10ms to do the job.

And the 248g/min injector at higher speed only has 5ms to do the job so needs to be twice as big.

Time available dictates the relative injector sizes.
Does it work properly yet?

The ecotrons seemed to be promising early on, but from what I read here the system is shit and a complete balls up as far as software goes.

Looks like there's a checklist as long as your arm that needs to be checked thoroughly every time there's a miss.

[TZ350]

Does it work properly yet?

Narr ... not yet.

Here is a run of torque curves from my Suzuki GP125 taken at WOT - 90% - 80% - down to 20% throttle.

332301

Below 20% (Red line) is where I am having my problems. Not sure why but probably more a 2T with EFI thing that I don't understand yet than the Ecotrons system itself.

[TZ350]

I did some further testing on the ion sensing system, choking the inlet to induce a misfire... I expected the measured ion current to drop to zero like it does with a four stroke... of course it doesn't! I think because the exhaust gas isn't purged from the cylinder every cycle like in the four stroke, the ions from the combustion are still there for the next cycle, whether there's fire or not, which seems obvious now. Nothing is ever clear cut with the two stroke cycle.

So next step will be to make a circuit to capture the pressure peak each cycle, then feed it into the ECU for datalogging, I should be able to detect misfire with that method.

Very interesting ......

[Drew]

Two stroke is always gonna read rich from measuring anything the exhaust I would have thought. Diagnosing a miss from ecu data would be a bloody nightmare.

That whole paragraph should be read as a question. I have no idea about it all, it's just ramblings.

[TZ350]

Two stroke is always gonna read rich from measuring anything the exhaust I would have thought.

Yes, always a bit rich but when it goes lean, like you say, it is hard to tell if it is really lean or so rich that its not firing and the O2 sensor is just seeing the wasted oxygen. I am still learning about this beast.

[TZ350]

332511

The Ecotrons EFI Alpha-N map load increases in 16 steps. So some time ago I used a flow meter to find the 16 TPS positions that equated to 16 even increases in airflow.

The curve followed this throttle plate curve I found on the net. I guess the offset is due to my curve starting at a slightly open position for the idle air.

332512

Interesting that 50% of airflow happens at 20% TP throttle position. The green shaded area is the area I am having most trouble with getting the engine response with the EFI Alpha-N map right.

332513

A series of dyno runs from 100% throttle down to the 20% green line. Also interesting that 50% air did not make 50% power. I don't understand that, I would have expected 50% air would equal 50% power.

The areas below 20% throttle represent a very small area on this collection of graphs but I have found it to be a huge problem on the track with throttle response. They also represent half the steps on the Alpha-N map.

When everyone knows big power is at WOT who would have thought that so much importance was in that first bit of barely opening the throttle.


There are always losses in friction and heat transportation so the curve of powergain is seldom equal to air usage.


Back when programmable EFI was in its infancy they used to save room and data and more importantly time, by using the multiple smaller steps only in problem areas if that makes sense.
ie they did a basic map much like a 4 circuit carb pilot, cutaway, needle, main.
then used the rest of the 16 steps to full in the areas where it stumbled
smaller engines and single and twins and rotaries were far less forgiving then 4 and 8's.
I remember Riley Will saying something on Pitlane about someone (Aprilia i think) basically plotting the flow of a carb and then recreating it with the efi, to get rid of the twitchiness.

............... EFI :eek5:

[FastFred]

332512

Interesting that 50% of airflow happens at 20% TP throttle position.

Seeing it mapped out like that sure makes it much easier to visualize.

[TZ350]

332640332639

Below is an extract from DirtBike that talks about the EFI KTM250. Interesting it mentions exactly the same problems with throttle response that I am having and that it mentions a crankcase pressure sensor.

https://dirtbiketest.com/fresh-dirt/two-stroke-fuel-injection-ktms-path-to-tpi/#ote9PlJBGtOBGJI6.97 (https://dirtbiketest.com/fresh-dirt/two-stroke-fuel-injection-ktms-path-to-tpi/#ote9PlJBGtOBGJI6.97)

<ins>Now using accepted and understood parts it all came down to processing the information and getting the mixtures right. Quickly. The window of time for the injector to be open and getting the large amount of fuel a two-stroke needs is the challenge, especially in even smaller displacements we are told. Plus when a two-stroke has a “flame-out” inside the combustion chamber, it can take up to 50 strokes for the engine to recover. This was a big issue in high RPM, low throttle times. For instance when you are going down a hill with the engine revving and then you give it a little gas. Making the throttle response as good as that antiquated carburetor was very difficult. There is not a lot of time for the computer to decide how much fuel and when to shoot it from one stroke to the next since the conditions inside the two-stroke engine can change drastically and very suddenly. Even small things like having the engine’s crankcase pressure sensor and fuel injectors mounted so that vibration was not affecting them were lessons learned in testing. Luckily the new 2017 engine was designed from the beginning to eventually have a non-carbureted fuel system so it would vibrate less and also be able to produce as much electrical power as would be needed.</ins>
<ins>Read more at </ins>https://dirtbiketest.com/fresh-dirt/two-stroke-fuel-injection-ktms-path-to-tpi/#Oo5mp1B4YRrV2OU2.99

332641332642

The crankcase pressure sensor seems to be taken off the back of the cylinder and go up to a sensor in a plenum behind the motor.

Very interesting ..... :shifty:

[Drew]

From skimming that article, I didn't see the even bigger improvement KTM made to their new 2 stroke.

Look up why they put a counter shaft in the new bike.

It's absolutely fucking insane the issues (including snapping rear shock shafts) From the vibration a high revving two stroke creates.

You're a clever cunt TZ (TZ got auto corrected to RD and I feel compelled to make old age jokes), so start considering balancing that shit up.

[TZ350]

You're a clever cunt TZ (TZ got auto corrected to RD and I feel compelled to make old age jokes).

Thanks, and when I was a little RD I always wanted to be a TZ when I grew up ... :laugh:

[Drew]

Thanks, and when I was a little RD I always wanted to be a TZ when I grew up ... :laugh:

I bring it up because KTM found that the rebound port on the shock had to be made perpendicular to the crank rotation, or the vibration would stall the fluid in the port.

One can see the potential for fuel to do the same thing on the way I to an injector.

[TZ350]

That is a very interesting point. Thanks.

[TZ350]

332723

Red line is throttle, Blue is rpm and Yellow LamWO2 sensor.

Same rpm and load/fuel injection amount at both cursors.

Nothing happens until the engine slows down to about 7k rpm where the pipe starts to work against the engine. Then it fires and Lam goes from lean to near right. Then there is a period of rough running pulling out of the pipes reversion hole. Then takes of at Lam 0.88 as it gets on the pipe.

The puzzle is, why does it fire when the pipe works against the engine and not while the pipe is in tune with the rpm as the motor is slowing down? ... :scratch: same throttle and fueling both sides.


TZ does your ecu change fuelling using feedback from the Wideband at all?

No


I'd like to see injector pulse width in that graph as well


I should be able to do that.


Are you saying the first "lean" section after throttle opening is only lean because it didn't fire and therefore could actually be too rich fuel/air to fire?

Yes I think you are right. It looks lean but it is too rich to fire. But why????


Same rpm, same throttle position, different airflow.

Above 7k RPM the on-pipe and off-pipe air flow is too different, the on-pipe fuelling (what you've tuned for) will not support combustion off-pipe. Way too rich, true lambda probably around 0.5 or worse.

As the engine speed falls below 7k rpm, the on-pipe and off-pipe air flow is not so different, true lambda is approaching the rich limit until it supports combustion.

332727

Once combustion begins the small increase of airflow from the pipe effect will bring the lambda above the rich limit, 'clearing' the cylinder.


Yes Nath I think you and Brett are right, what you say makes sense. Thanks.

[TZ350]

I'd like to see injector pulsewidth in that graph as well

332767

Pink line is injector pulse width. Blue RPM and Brown is wide band O2 sensor.

WOT, same RPM, same injector pulse width, different Lambda.

I think Nath88 is onto it.


Same rpm, same throttle position, different airflow.

332725

[FastFred]

Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.

I was just about to recommend using the map switch :( I tried it out this weekend, its not dialled yet, but it's the best so far, I can roll along at 8500rpm and open and close the throttle as fast or slow as I like and it always responds. I will tune the main map by lambda feedback (it's pretty much done using values from before), and the misfire map by holding the engine at a load point, then holding the kill switch for a second or two, then release and judge the response when it comes back on as rich or lean, it should be instant and clean like a carb.
The map switches when the peak pressure between 85 crank degrees and 125 crank degrees, measured at the PV vent (with an adjustable bleed to atmosphere) reaches 102kpa, atmosphere is 101kpa here.
Means I'm confined to riding at sea level until I sort out a better implementation. Hoping the piezo pulse sensor will be the ticket, since it doesn't care about absolute values, If it works I'll make a bunch of them.

I think the piezo on the cylinder head idea could work, if the signal is not too noisy.

Between TZ and Nath88 we may yet see a practical DIY method for fuel injecting two strokes.

[TZ350]

would it be possible to somehow "record" an exhaust harmonic frequency in conjunction with a tps an wideband lambda on a carburated twostroke?

Good idea Sandokan, I didn't record the exhaust but I guess its possible. I did use the wideband lambda and carb to get an idea of what the fuel map should look like.


Put a Piezo thing ring under one of the headstud nuts or between head and sparkplug and a very rude instant cylinder pressure signal can be had.
When piston is halfway down You will know if it fired or not. And then: Who tried it already and why does it not work?

Another good idea, thanks Niels. It could well work, unfortunately my Ecotrons software does not have a suitable input available, it is short on alternative inputs. But it does expect a MAP sensor which is why I am trying to see what can be done with that.

Unlike some other EFI systems the Ecotrons software does not allow for a binary input that switches between two maps. But there is a place for an analog input from the MAP sensor to influence the Ecotrons software to adjust the predicted fueling requirements from the Alpha-N map at any TPS/RPM.

The Ecotrons software adjusts the injector pulse width according to the Alpha-N map and input from the MAP sensor. It is how to make use of that relationship for fuel injecting a two stroke which is the trick I am trying to learn.

[TZ350]

332794

Smoothed the MAP sensor reading by adding some volume by replacing the MAP sensor hose with a small chamber.

332793

MAP sensor Yellow line. Interesting that the line on the left as the engine is still winding down and zero throttle is higher than the MAP pressure line at WOT and as the RPM starts to rise again.

[TZ350]

Same rpm, same throttle position, different airflow. The pipe effect on a misfire is very weak if it exists at all...

332725

My graph doesn't show this well, but above 7k RPM the on-pipe and off-pipe air flow is too different, the on-pipe fuelling (what you've tuned for) will not support combustion off-pipe. Way too rich, true lambda probably around 0.5 or worse. As the engine speed falls below 7k rpm, the on-pipe and off-pipe air flow is not so different, true lambda is approaching the rich limit until it supports combustion. Once combustion begins the small increase of airflow from the pipe effect will bring the lambda above the rich limit, 'clearing' the cylinder. You could install any old MAF sensor to prove this.

I'm still working on the Ion sensing, but I'm getting impatient so I'm going back to measuring the pressure at the PV vent since that worked the best so far (I now have an adjustable bleed to atmosphere so I can adjust it's sensitivity), and using that input to try a table switching approach. Have a fuel table for no-pipe effect, and a fuel table that incorporates pipe effect. Theoretically I could put a box-style muffler on and tune 1 table, then put the expansion chamber on and tune the other. Pressure pulses will determine whether the pipe effect is active and ECU switches between the tables accordingly. Away from the pipe's effective rpm the tables should be more and more the same.

I'm thinking a box-muffler would provide no scavenging effect, and no return wave effect, can someone confirm that?

I'm also designing a 'pressure pulse' sensor. It's basically a piezo electric microphone hooked up to exhaust pressure, it will more accurately and quickly detect the exhaust pulse from the cylinder than the pressure sensor. I figure I can hear when the engine is firing clear as day, why not use a microphone...


Same rpm, same throttle position, different airflow.

332725

I understand Nath88's explanation for the change in the LamW02 trace Yellow line. .... :niceone: good one.

332825

Pressure in the exhaust header pipe as measured by a MAP sensor, Yellow line, RPM Blue line, LamWo2 Brown line.

Through a one way valve arrangement the MAP sensor only measures the high positive pressures of the returning pulse in the header and does not see the negative suction pressure.

Interesting that the MAP pressure line on the left as the engine is still winding down and at zero throttle is higher than ambient and the MAP pressure line on the right at WOT which starts at ambient before obviously rising again as the engine gets on the pipe. There is quite a sudden drop in MAP pressure (Yellow line) when the throttle (Red line) goes from fully closed to fully open.

But why does the header pipe positive pressure behave like this? ...... :scratch:.. high and above ambient when there is no throttle and the engine is winding down then goes lower when it's on WOT and starting to pick up again.


I saw something similar with mine.
Since we're measuring the peak, it implies the average pressure in the pipe must be lower than atmospheric by a fair bit?
Has anyone witnessed a vacuum in the pipe at any time?

Once the engine starts making power the exhaust flow creates pressure in the pipe due to the stinger restriction.

A differential pressure sensor with the average pipe pressure as the reference might be the go. Or my new sensor, should be testing the prototype next week.
332827

Can you set the crank angle for sampling the MAP sensor with the ecotrons?


Can I suggest that the whole system - from inlet via crankcase to muffler - has one end closed when the throttle is shut and the chamber tailpipe is then doing what it's supposed to and acting as a pressure bleed resistor. Open the other end to atmosphere - open the throttle - and the system pressure should drop to atm and possibly lower momentarily.

That is possible I guess, but on overrun with throttle closed and the motor not firing what could be creating the pressure in the pipe?

You would think any residual pressure from a full power run would have bleed away quite quickly but on other graphs it actually looks like it builds up a bit.

Bit of a puzzle


Can you set the crank angle for sampling the MAP sensor with the Ecotrons?

No. But I am very interested in the sensor you are developing.


That's a shame, timing will be key for this thing.

I thought that it was showing atmospheric pressure off the throttle, going into vacuum as you opened the throttle. What pressure is atmo?
But if its producing positive pressure with a closed throttle I'm out of ideas... Definitely qualifies as a puzzle.


Pipe pressure varies not only with throttle and rpm, it can also vary locally because of wave superposition.

It might be instructive to experiment with several pressure take-off points along the pipe.

332834

Yes I can see how wave superposition can create a localized high pressure spot although I would expect the node to move with frequency as the RPM dropped. I will look for that next time.


Assuming that the one way valve is working properly, and you still have that bleed between the one way valve and sensor, the lowest pressure you should ever see at the sensor is atmospheric, no matter how low the pressure in the pipe is.

Yes, that is how I read it too.


... the drop in pressure when opening the throttle:
Closed throttle => ~0 airflow thru the header
Open throttle (even without firing) => >0 airflow the the header.

Now, depending on the geometry around your pressure pickup position its not at all unlikely that the pressure drops in that position simply due to flow. -Think venturi..

The closed throttle no flow pressure was higher than atmospheric and dropped to atmospheric when the throttle was opened again. Your venturie idea is interesting.

Pressure node and venturie effect could explain it....... :scratch:

332835


I was just about to recommend using the map switch :( I tried it out this weekend, its not dialled yet, but it's the best so far, I can roll along at 8500rpm and open and close the throttle as fast or slow as I like and it always responds. I will tune the main map by lambda feedback (it's pretty much done using values from before), and the misfire map by holding the engine at a load point, then holding the kill switch for a second or two, then release and judge the response when it comes back on as rich or lean, it should be instant and clean like a carb.
The map switches when the peak pressure between 85 crank degrees and 125 crank degrees, measured at the PV vent (with an adjustable bleed to atmosphere) reaches 102kpa, atmosphere is 101kpa here.
Means I'm confined to riding at sea level until I sort out a better implementation. Hoping the piezo pulse sensor will be the ticket, since it doesn't care about absolute values, If it works I'll make a bunch of them.

332861

Just realised/remembered that the ecotrons EFI system does have a switch for switching between two maps. I had been using it for so long as an input for the wide band O2 sensor that I had forgotten about it.

But after I have got the on the pipe map sorted it looks like I may be able to use one of your switches to then develop an off pipe or miss fire map.

The performance switch just switches in another table of values that are used to divide the values in the main map. Ie if you have a load value of 120 in the Alpha-N map and switch in the performance map that has a Lambda value of 0.85 then the Alpha-N map gets divided by 0.85, 120/0.85 = 142 ie the result is a richer mixture for exceleration.

I guess there is no reason why the performance switch can't be used to lean the Alpha-N map off when the engine has misfired or is off the pipe.


If it's another TPSxRPM table with multipliers it should work great. I'm doing the same thing right now but in a spreadsheet, then dropping the numbers into the tuning software. The multiplier is the pipe effect on airflow so it's a more sensible value to use anyway. You'll need to extrapolate the tuned 'firing' map you have into the skip-fire/misfire regions as best you can. Making the switched input to feed into the ECU will be the hard part, but I want to do that for my setup as well to free up the MAP input, and make the sensor unit a plug and play product for any ECU.

Had a play with the piezo disc for the exhaust pulse sensor, looks promising, very sensitive, minimal noise, nice.

https://www.youtube.com/watch?v=C5yOTfo2FKw


If it's another TPSxRPM table with multipliers it should work great. I'm doing the same thing right now but in a spreadsheet, then dropping the numbers into the tuning software. The multiplier is the pipe effect on airflow so it's a more sensible value to use anyway.

Had a play with the piezo disc for the exhaust pulse sensor, looks promising, very sensitive, minimal noise, nice.

Yes that piezo looks promising as the basis for a switch. I will definitely be a customer for one.

332883

This is the Ecotrons EFI softwares Basic 16x12 Alpha-N map.

332884

When the "Performance" switch is activated the corresponding cells in this 16x12 map are used to divide their related values in the original Alpha-N map to give an alternative fueling value.

This seriously looks like it could be used in the way you have described previously of leaning the fuel off when there is less air flow when there is no pipe action drawing air through the motor.

[TZ350]

Another unfulfilling and downright frustrating experience with Ecotrons support Dept.... :brick:.

Did it occur to you TeeZee that just possibly, you know more about the system now, than they do.

With small capacity high performance 2T EFI that maybe true ... :laugh: ... and sure, in fairness you can't expect them to be onto everything.

But what I asked for was a simple change to a basic cal file to turn on the LamO2 sensor. I want my cal file to have both "Injection Angle End" and "LamWO2" options.

Its easy enough, other EFI software packages come with tick box's for that sort of thing. With Ecotrons you have to enlist their assistance and it is often a slow difficult negative experience dealing with their help dept.

[TZ350]

I received a reply from Ecotrons lastnight. The advanced calibration file needs these changes to be able to monitor and record results from the wide band oxygen sensor.

CV_SSFLAM = 4
CV_SSWO2 = 1
VAL_uLamSlope = 0.3
VAL_uLamOfs = 0.5

Hopefully I will get to try it out this afternoon.

I used to think that it was easier for the local 2T Kawasaki 350 and Yam 250 that are successfully running EFI because they did not rev much past 9,000 and so only needed one logical injector and that the bigger capacity helped mask fueling miss steps.

I started to have doubts about that when I saw that some small 2T drone aero engines 25cc or less were successfully running EFI. But these basically run at a constant speed.

The issue for me is drivability, i.e. throttling off for a corner and then on again exiting. After Nath88 pointed out that you can have two different air flows through the engine due to pipe action/non action for the same Throttle/Rpm position on the Alpha-N EFI fueling map and remembering Frits's explanation of how the wave action in a pipe collapses when throttling off and how it takes some time to re establish after throttling on again.

I now think that one of the big differences is how aggressive the pipe is. On a small capacity high performance race engine the pipe action in drawing air through the engine would be much more variable than the pipe action on a larger capacity MX or Trail bike engine setup more for power range and usability than outright power hit.

So in getting 2T EFI to work, it turns out the pipe makes a huge difference, who would have thought ...... :rolleyes:

[husaberg]

I received a reply from Ecotrons lastnight. The advanced calibration file needs these changes to be able to monitor and record results from the wide band oxygen sensor.

CV_SSFLAM = 4
CV_SSWO2 = 1
VAL_uLamSlope = 0.3
VAL_uLamOfs = 0.5

Hopefully I will get to try it out this afternoon.

I used to think that it was easier for the local 2T Kawasaki 350 and Yam 250 that are successfully running EFI because they did not rev much past 9,000 and so only needed one logical injector and that the bigger capacity helped mask fueling miss steps.

I started to have doubts about that when I saw that some small 2T drone aero engines 25cc or less were successfully running EFI. But these basically run at a constant speed.

The issue for me is drivability, i.e. throttling off for a corner and then on again exiting. After Nath88 pointed out that you can have two different air flows through the engine due to pipe action/non action for the same Throttle/Rpm position on the Alpha-N EFI fueling map and remembering Frits's explanation of how the wave action in a pipe collapses when throttling off and how it takes some time to re establish after throttling on again.

I now think that one of the big differences is how aggressive the pipe is. On a small capacity high performance race engine the pipe action in drawing air through the engine would be much more variable than the pipe action on a larger capacity MX or Trail bike engine setup more for power range and usability than outright power hit.

So in getting 2T EFI to work, it turns out the pipe makes a huge difference, who would have thought ...... :rolleyes:

Maybe the bang bang set up.
https://www.pressreader.com/australia/fast-ford/20140227/282050504983923

https://www.youtube.com/watch?v=Om-9DUmAtIA

[TZ350]

Thank Norman, Frits and others. I found here many interesting ideas. We are small company which works like "engine atelier" for small aircrafts, UAV and other applicarion where weight and fuel economy are vital. To the moment numerous codes like ~bimotion ~mota ~Ricardo Wave ~Lotus concept
gives irreal results on boxer 2-strokes engines I produce. So one of my present objectives is to make parametric CAD model linked with CFD simulation of 2-stroke engine complete from intake to exhaust. I believe will sucseed in ~4+ month by myself and understand what have to be changed.

http://www.reaa.ru/cgi-bin/yabb/YaBB.pl?action=downloadfile;file=2b350.jpg



There you are TZ, maybe a successful 2T EFI system, looks like an injector port in that throttle body.Lot easier to do FI on an aero-engine...


This throttle body we got from Ecotron. We often have problem with components quality and have to do inhouse.
Now we 5-axis mill bodies and make our proprietary 2T EFI system, very lightweight and poverfull :cool:
We place some of sensors in one ECU box and got by wires cylinder head themperature and throttle angle.
May be one day we will make 2T ECU as a "box product"
http://www.reaa.ru/yabbfiles/Attachments/____093_001.jpg


The exhaust pressure sensor I was using died by drowning in exhaust oil, so it motivated me to rig up the new exhaust pulse sensor for a test.

333019

Green line is the exhaust pulse, rate of change of pressure. Red lines are the sample window (ECU takes the lowest value inside this window). White lines are the trigger wheel teeth as the crank rotates. There's 20 teeth on the wheel, first tooth is at 72°BTDC. Primary exhaust pulse hits the sensor at around tooth 11 (126°). On this trace we see 2 firing primary pulses followed by a misfire pulse, caused by a throttle blip at 2400rpm, however engine speed increases an unknown amount over the 3 rotations. Either way the pipe is way out of sync with the engine at these revs. I later tweaked the sample window from 30 to 45 degrees duration to properly catch the pulses.

I also took the bike to the dyno, it was running too rich, perhaps due to the dead sensor, maybe some other factors. Made 45hp on the dynojet, sounded rich all the way through but the curve was pretty consistent with carb 2 strokes, maybe a bit stronger coming onto the pipe. I'll scan the chart at some point and post it.


I did some experimentation with the piezo sensor on the road yesterday, saw much less signal amplitude than the previous test and DC voltage seemed to vary a bit over time, but I think the hose was kinked and I know the wiring was crap. So I've fixed those things and will see if it's better/back to normal today.

Also leaned it out from where it was on the dyno, target AFR is 14:1 before 5300rpm (anti-resonance point) then 13.4:1 AFR to 8500rpm (peak power) then it slowly leans out to 13.8:1 at 9800rpm. It feels pretty happy, probably more to gain here. I think it still blows a little smoke on full throttle before anti-resonance, might be able to go a bit leaner still.

Totally looking forward to hearing how your piezo sensor experiment goes. I have been trying to re map my CPU for all low throttle fully on pipe running in the hope I will be able to get a piezo sensor switch from you sometime to see if I can use it to switch between low throttle on and off pipe maps.


I did another test just free revving, signal output looks better than before, I'll do another road test this afternoon. The sensor follows the rise and fall of the overall pressure in the pipe, throws the cycle to cycle numbers off a bit so I'll add a filter to get rid of that. Hopefully a switch isn't too far off, putting the pressure on!

Current test rig:
333094

A more general question, if the engine is 'clear' but it's blowing some blue smoke at low-rpm full throttle, is it too rich? Is there any harm in going leaner until the smoke clears?

[TZ350]

333134333135

I took a look at a Piezo switch and thought that I might be able to use the exhaust pulse instead of a finger press to activate it.

333136

There is a 100Meg resistor across the piezo sensor which acts as the load, piezos need high impedance on the output to measure low frequencies, so that's fine. However the next 100Meg resistor and 100pF capacitor form a low pass filter of 15hz. This acts to smooth and slow the input, probably so it works decently as a switch instead of flicking on and off with any variation of pressure applied to the piezo. It may work, I would expect a delay between the pressure input and when the mosfet has enough voltage at it's input (gate) to 'switch'. The switch threshold would be set by the gate voltage of the mosfet combined with the filter.

My pulse sensor gives clear indication at high rpm light throttle, which was the problem area with the pressure sensor used earlier. At 7700rpm the exhaust pulses are the strongest, so that's probably the peak resonance of the pipe. However at around 4600rpm the indication is poor, not a big difference between full throttle and closed throttle. The exhaust pulse from the port is probably being cancelled by the existing wave, why at 4600? It's giving me a headache so I've made the maps the same below 5000rpm, low rpm response was never an issue.

333187

Got a Piezo switch today, 24V 200mA max.

333188

Tried it out on my trusty PLC test bed. Piezo switch works great, pulse output non latching. Will check later how it goes with 12V and how square the wave form looks on a scope.

[TZ350]

.

Following on from Nath88’s suggestions about the amount of air flowing through the motor that needs fuelling depends on whether the motor has fired and the pipe action has sucked air through or not.

I have been looking for ways to see if the engine has fired or not. And I like Clints idea that measuring the in cylinder pressure just before exhaust port opening would be a reliable way to tell if the motor has fired or not. It would not take a very sophisticated pressure sensor to do that. One would not need to know the real pressure, only that there is more pressure and a simple home made sensor using a piezoelectric disk from a hobby shop may be enough to do that.

It would not have to be that clever, with the help of an Aduino mini all I would need to know is that between two consecutive ignition trigger pulses there was an in cylinder pressure rise of a predetermined magnitude or not.



Clint Gray - www.tfxengine.com (http://www.tfxengine.com/) sent me some comments by email that made sense to me and with Clint’s permission I can share them.

The equipment that we sell is for engine tuning via measuring cylinder pressure, port pressure waves etc. per degree of crank rotation. That might be overkill for what you need.

There are 2 ways that you could do it in the cylinder.

The first would be to use a true cylinder pressure sensor which is necessarily exposed to the whole cycle. This would involve drilling and tapping the head.

The second way to do it would be to install a pressure sensor part way down the cylinder wall. It would involve drilling a tiny hole roughly 0.75mm to 1mm diameter straight into the cylinder wall then mounting a sensor somewhat back from the hole external to the cylinder.

As an example, if you drilled the hole anywhere in the cylinder wall circumference so the piston ring exposed the hole to the pressure from about 70 ATDC through all the crank angles to 70 BTDC, all you would need is a low pressure sensor mounted say an inch behind that hole (i.e. the hole is a 1 inch long passageway feeding the sensor), then take your reading at 80 ATDC and 80 ABDC. So twice per revolution 180 degrees apart. There would be quite a difference in pressure if the engine fired, yet the peak pressure and average temp the sensor would be seeing would not be all that high.

We also have a sensor that will work in the cylinder wall like described but it is super-fast etc. For what you are doing, if you mounted a sensor as above, the sensor would not have to be super-fast, nor would it see high pressures, and average temps wouldn't be all that high considering its location and the part of the cycle it is seeing. Also the hole is a dead end hole so there is no significant flow in that hole, not like a hole that is open to the atmosphere. You might be able to find/use a much cheaper sensor if you go through the cylinder wall.

Further to what I wrote above, regarding a small hole in the cylinder wall. As I mentioned you could measure twice per revolution 80 ATDC and 80 ABDC, or even just once per revolution at 80 ATDC and use a threshold pressure value to determine if it fired or not.

However, it would be simpler to take a reading at 80 ATDC and 80 BTDC then compare the two pressure values per revolution. That way you don't need to have a threshold pressure value, just compare the two directly every revolution, and since the readings are not 180 degrees apart, they are 160 and 200 degrees apart, it would be easy to know which reading is the ATDC reading and which is the BTDC reading.

The fact that the sensor is slow, say a ms delay shouldn't matter either. It is still going to "see" the pressure at 70 ATDC it's just that it's going to be a little bit of time for the sensor to fully register what it sees.

You will be able to tell right away whether you need to delay the reading a full ms or much less than that, because when the hole is closed the pressure the sensor is seeing is only going to be crankcase pressure, so not much, and then when the hole is uncovered it will jump up very quickly, to say 150-200 psi. A slow sensor may take a full ms to fully register a pressure to the nth degree but it will probably register most of that pressure rise in much less time than a ms. Lets say 200 psi is applied instantaneously to your ms delay sensor, well it may only take 1/10th ms for the sensor to register 50-100 psi of that 200 psi and that would be plenty to tell you that it fired. If you go this route use a sensor good for 300 psi or a little better so it has a safety factor.

If you run a small tube that seals (need good contact for heat transfer) to the engine, and it runs between the cylinder wall hole and the sensor, then the actual sensor (which is likely sizeable) can sit outside the engine where it has space. You still want the sensor fairly close to the engine of course.

FYI we have several customers that drill their cylinder walls and install one of our threaded M5 sensors, so it is not uncommon. They don't do it for the reason you are doing it for, they do it to more accurately measure cylinder pressures during the low pressure portions of the cycle. A low pressure sensor is used instead of a combustion sensor.

I think that you can still put a hole in at 70 ATDC and get a cheap and "slow" sensor to work. The average temperature from 70 ATDC to 70 BTDC is not going to be very high, and it's a dead end hole so not much flow.

With your 1/4"BSPT thread try to sleeve the inside hole of the sensor so that there is as little volume inside there as possible, without contacting the diaphragm in the sensor of course.
You want to have as little transfer of gases as possible moving to and fro, makes for less heat and a quicker fill (reading).

Clint.


Excellent lecture from Clint Gray, combining theoretical knowledge and practical thinking. I especially like the simple asymmetrical signal spacing.
Here is some more injection lecture for the Christmas holidays:

EDIT: uploading failed because the file is too big (2793 kB). You might try to find it yourself on the internet.
Search for WO2016193902A2 : Internal combustion engine having two fuel injectors per cylinder and control method therefor.


I believe this is the same patent.
http://www.freepatentsonline.com/20170159598.pdf

Update on my thing:

-I'm overdriving the piezo transducer, they're rated at 15V AC, I'm seeing an output of 50V. The signal diminishes over time, quickly at first, then it settles. Could market it as 'self calibrating', but the better option would be to use a smaller disk to reduce the output.

-The signal to noise ratio is still not that great, and I'm hampered by being fixed to 1 value where the fuel table switch occurs. The ideal switch value varies by RPM.

333724

-I have found that the pipe effect on overall air flow is greater when the throttle is more closed, it's about 2.5x 8000rpm 100% throttle, and about 4x at 0% throttle (by extrapolation). I guess the pipe is providing a bit more intake vacuum, overcoming some of the throttle restriction.

-Richening the air fuel ratio to approx 14.4:1 from 15:1 has stopped the unwanted ARC/HCCI operation at light throttle.

-The next trial will be to use a differential pressure sensor between the intake and the crankcase. I've previously found crankcase vacuum increases with pipe effect, but it's relative to the total pressure in the system, which is influenced by atmospheric pressure and throttle restriction. Accounting for both with differential pressure might give me a usable signal. KTM must be doing something like this, since they are measuring crankcase vacuum.