ESE's works engine tuner

[Moooools]

Thanks Bucket and Mooools

To get started, most of the info for VE, Speed Density and Alpha-N maps can be gleaned from the EngMod2T simulations.

Because of the pulsing in the inlet tract that Mooools talked about and which is particularly bad in a 2-Stroke, the Fuel injection system we are getting has a Speed Density map for low RPM and uses Alpha-N for the high RPM end.

I have been told that as an optional add on, it can also have a mixture adjustment with exhaust temperature option. I am not sure how that works but hopefully it means we can give it a target ET and it will maintain it just like Wobbly has talked about for maintaining optimum AFR with changes in conditions during the day.

I am not sure how the injection timing works but the system triggers from the existing ignition pickup. Because I want to inject into the transfers while the are open and flowing, I guess it will be easy enough to fit a dedicated trigger at some other point to get the injection timing right.

Anyway hopefully Chambers and I will have our kits by the end of the week.

I am quite surprised the fuel map control isn't around the other way. With tps at low rpm and MAP at high.

Does it not have adjustable injection timing?

[Frits Overmars]

....I have been told that as an optional add on, it can also have a mixture adjustment with exhaust temperature option. I am not sure how that works but hopefully it means we can give it a target ET and it will maintain it...

So if your exhaust gas temperature is lower than it should be, the mixture is made leaner, right?
Fine, except that EGT drops when the engine starts to detonate. Need I paint the rest of the picture?

[TZ350]

I am quite surprised the fuel map control isn't around the other way.

Maybe it is, know more when I get may hands on it.

Does it not have adjustable injection timing?

I will post more as we get to know how it works.

So if your exhaust gas temperature is lower than it should be, the mixture is made leaner, right?
Fine, except that EGT drops when the engine starts to detonate. Need I paint the rest of the picture?

Hmmmm I see you point, hopefully they have this covered as it also has a cylinder head temp sensor. But I don't realy know, or even know if I properly understood what they were trying to tell me.

I guess I will find out in due course if we have a lemon or a peach.

[bucketracer]

Mountain Thunder- Methven Street Race 2013- Buckets- Race 3




There are so many really cool Bucket race meetings.

[bucketracer]

I am quite surprised the fuel map control isn't around the other way. With tps at low rpm and MAP at high.

From what I can make out from the documentation downloaded off the net for TeeZees EFI, the makers intend using MAP for low rpm and TPS for the high end.

[Flettner]

TZ don't be too concerned, there will always be doubters,I have running proof that EFI works well on a twostroke. Although I only understand the Link computer, much of this has already been done by Link all you have to do is choose the options you want.
Frits you can run the deto sensor back into the computer, it will adjust, retard and rich. The Link will do this.

[rgvbaz]

I think, also taking the gear ratios of TZ's engine into consideration, a plot comparing rear wheel torque through the gears, with both curves geared to the same top speed would be quite handy. That one with the bigger area under the curve, wins[/SIZE].

Not to sure if the area will tell you the winner?

If you plotted force by distance this would give you the total work the curve could do, but we are really after the rate of doing work (power) so we would need to consider time.

I know that power = force*velocity, which is what we would get from the force v speed graphs but the scale on the speed axis would be wrong; it has a liner scale but change in velocity is a square relationship.

Dave.

[bucketracer]

TZ don't be too concerned, I have running proof that EFI works well on a twostroke.

Also the same EFI as TeeZee is getting is used on 2-Stroke powered Para Gliders



Engines used are almost exclusively small two-stroke types, between 80cc and 350cc, that burn mixed gasoline and oil. These engines are favored for their high output power and light weight. For years, these engines used carburetors because of small volumes of production. Now with our low cost and simple 2-stroke fuel injection kits, it is the first time its commercially viable to convert them to the fuel-injection.

Certainly these engines can take all advantages of fuel injection, namely, better fuel efficiency, more power, easy to start, compensations to temperature / weather changes, and self-adaptations to altitude changes, etc.

We have customers successfully installing our EFI kit to their ParaMotor engines already. Some earlier adopters have flown with our EFI kits. The simplicity of our 2-stroke EFI kit makes the conversion comparatively easy for ParaMotor applications.

[Frits Overmars]

....Frits you can run the deto sensor back into the computer, it will adjust, retard and rich.

I am all for using that deto sensor signal as you describe, Neil. I just wanted to warn TZ about the risk in using an EGT signal for EFI purposes.
BTW: this is starting to look like German: they cram their sentences with abbrevs (and still manage to build sentences twice as long as the English).

[fatbastd]

Haleijulia!! It's taken me since before Christmas, but I've finally managed to get to the end...

I thought I had a rough handle on how things worked, but am nothing but a festerer compared to what I've read here...good effort. I have a garage full of two strokes and shall be nicking good stuff from here to make them faster, safer.

Just a couple of thoughts: Wob's comments regarding selection and sticking to the aim (more than 30RWHP) sticks out like dog's when you read stright through all the last 745 pages and we all want to see the end result and how it's done. Against that ideal, I know TZ350's view - it's all good fun, so a few diversions are OK, and that's the real benefit.

Just thinking about big TZ's posted recently - may be 100 pages back..the engine from Trev Discombe's Nicco 750 that Stu Avant rode to a win at Pukekohe in the Marlboro series is back in it's own frame in Aucklland and regularly ridden (if not that often). The motor in that bike is quite stock, and alwys was - as Avant said when quizzed as to how he pulled off the win 'I just hung my arse out a bit'. There was also a mention of there being 9 TZ750's in NZ - a little pessimistic - I know of 13 at the last count IIRC (2 recent arrivals in Invergiggle), with 5 living within 50m of each other! One was shipped overseas a couple of years ago, to the USA. In the late 70's there were 5 new monoshocks in boxes in Auckland that went directly overseas again -someone I know was taken to see them at the time. The ex-Hawera bike (now sold) rated a mention here as being a very original bike - not so: the frame was by Ken McIntosh (I had the original frame that I believe TD wrote off- now recontructed and in a bike in Brisbane), the forks in the bike when Scotty rode it were RZ500 (and crap for the job) and the motor has a set of replacement crankcases. I believe the new owner is keen to drag it out for whizz around.

Anyway, enough big two-stroke crap: it's looking like a kid of mine is keen to ride and buckets are a favoured jumping-off point (pardon the pun). It might have to be a four-stroke to get things going (ease of riding, stock - min maintenance), but greduating to a proper two-stroke would be a development plan. Might have to swing my fat leg over one too, though it's have to weight about 35kg to give me a competitive power to mass ratio!

I know some of you buggers in the flesh, so I'll be looking over your shoulders soon, prolly at Mt Wellington..

Cheers

FB

[husaberg]

Haleijulia!! It's taken me since before Christmas, but I've finally managed to get to the end...

I thought I had a rough handle on how things worked, but am nothing but a fester compared to what I've read here...good effort. I have a garage full of two strokes and shall be nicking good stuff from here to make them faster, safer.

Just a couple of thoughts: Wob's comments regarding selection and sticking to the aim (more than 30RWHP) sticks out like dog's when you read straight through all the last 745 pages and we all want to see the end result and how it's done. Against that ideal, I know TZ350's view - it's all good fun, so a few diversions are OK, and that's the real benefit.

Just thinking about big TZ's posted recently - may be 100 pages back..the engine from Trev Discombe's Nicco 750 that Stu Avant rode to a win at Pukekohe in the Marlboro series is back in it's own frame in Auckland and regularly ridden (if not that often). The motor in that bike is quite stock, and alwys was - as Avant said when quizzed as to how he pulled off the win 'I just hung my arse out a bit'. There was also a mention of there being 9 TZ750's in NZ - a little pessimistic - I know of 13 at the last count IIRC (2 recent arrivals in Invergiggle), with 5 living within 50m of each other! One was shipped overseas a couple of years ago, to the USA. In the late 70's there were 5 new monoshocks in boxes in Auckland that went directly overseas again -someone I know was taken to see them at the time. The ex-Hawera bike (now sold) rated a mention here as being a very original bike - not so: the frame was by Ken McIntosh (I had the original frame that I believe TD wrote off- now reconstructed and in a bike in Brisbane), the forks in the bike when Scotty rode it were RZ500 (and crap for the job) and the motor has a set of replacement crankcases. I believe the new owner is keen to drag it out for whizz around.

Anyway, enough big two-stroke crap: it's looking like a kid of mine is keen to ride and buckets are a favoured jumping-off point (pardon the pun). It might have to be a four-stroke to get things going (ease of riding, stock - min maintenance), but graduating to a proper two-stroke would be a development plan. Might have to swing my fat leg over one too, though it's have to weight about 35kg to give me a competitive power to mass ratio!

I know some of you buggers in the flesh, so I'll be looking over your shoulders soon, prolly at Mt Wellington..

Cheers

FB

Great post,Now if you can pm me those address's for all those TZ's..
I can't let that last bit go though 4 stroke for lower maintenance? i am guessing your son hasn't done mx then.
Those 4 stroke things have far to many whirling bit's that wear out and have the propensity go pop in a expensive way at any time.
Two stroke's on the other hand are the paragon of reliability....

As people have, i guess sussed out already. I will be very soon to make a few, Well very Aprilia like cylinders (With more than a lot of help from Neil ie Fletner)
These cylinder's and heads have been modeled on the RSV. As beautifully detailed in the engine drawings from Frits( ie triple ex and 5 transfers and a 2 stage blade pv.)
So if everyone thinks it is the most, illegal, underhand, dastardly, or not in the spirit of Buckets etc please speak now or for ever hold your piece.
If not those that want one let me know.
In the spirit of bucket racing the cylinders will be sold as un-machined castings. (In an effort to keep costs down)
The buckets will be a strictly a negligible profit sideline as the intention is to sell them mainly to people who have RGV250's and NSR250's the likes as a bolt on road kit up to around 300cc

Hopefully maybe Neil sorting out the PV and Head domes and machining and Mr Wob the pipes and so forth....
It would be kind of neat to sell Aprilia copy cylinder kits into Europe for people with Aprilia bikes with Suzuki engines.

[bucketracer]

Hey TeeZee I cam across this thread where Flettner talks about fuel injecting his Kawasaki 350, hopefully he won't mind it being re posted here.

http://twostrokemotocross.com/forum/...troke-article/

I use a Link Atom computer on my MX twostroke. Rear transfer port injection, by staging the injection, fuel wastage is reduced, more power, wider power spread. Enough oil deposit on the transfer runs down to the crankcase to service the bigend. It's been running for about eight months now.

This bike has a vairable rotary valve housing operated by the Ignitec ignition. From 55 degrees valve closing at low speed to 78 Degrees at full throttle.

Fueling changes. Link EFI has the ability to change the fueling as the head temp changes. With Ethanol the fuel requirement changes above 70 degrees C, more fuel required. This can be changed on a graph that uses TPS and Temp. This information is overlaid the main fuel map. Very handy with an air cooled engine.

The rotary valve still organizes the air into the crankcase, just has no fuel with it. Oil is still deposited from the injected fuel around the crank case and rotary valve via deposits in the transfer ports. One of the problems with the Link computer is some it's twostroke injection timing software is not operational yet. I can change the start of injection timing to a given point with the "on time" moving away from this point. I'm injecting approx over 180 degrees at full throttle (180 degrees injector on time ), so I have to set the start at approx 20 degrees after TDC ( quite a way before transfers open) so that at full throttle there is no injection still happening after transfer closes. If injection occurs after transfer port shut the fuel mixture on the next cycle is not so accurate ( power loss ). This I have found. Best it to have a fixed shut time ( approx 30 degrees before transfers shut ) and have the injection start vary. This will bring max injector start time to about 30 degrees ATDC at full throttle. This is what is needed, as up to about one third throttle is happening as the transfer is occurring. This I have found gives best bottom end power. Clear as mud?

In a nutshell, the injection timing is important. I can see why it's probably a good idea to use a small and a large injector, staged. The Link software is not able to do this in " twostroke mode" . Also there is an option to nail down the injector finish time and adjust the start time, or a center and adjust either way from that point. Also not available in twostroke mode. These options are available in fourstroke mode. So next step is to call the bike a fourstroke twin, 360 degree firing ( I don't need to use the ignition as this is done with a separate unit), This will use two drivers ( switches ) in the Link unit to run each cylinder ( if it were a twin ). Both drivers can be hooked together to run my pair of injectors each 360 degree cycle. This requires a cam sensor, I'll use a circuit called a flip flop connected to the ignition trigger ( single pulse per rev ). This circuit ( flip flop ) will only allow every second pulse to be seen by the Link computer, as far as the computer is concerned, a cam sensor. This will trick the computer in doing what I need it to do. Now all these options will be available. New Link soft wear will be available in eight months. I can't wait that long, I want it now. That's a big nutshell.

Yes I did think of using wobbly's ignitech unit. Cost a little more than the Link. I've used quite a few link units in the past on the Subaru powered gyro copters we build and have a good working relationship with the guys at link. But I was a little disappointed that the Atom unit I was sold did not have the suitable soft wear activated even though I was told that it was when I bought it. No problem, as it will be available in the next soft wear release. At the moment I'm "tricking" the computer into doing what I want. To be fair not a lot of after market computer makers have had a lot to do with transfer port injection where timing is so important. It is interesting to note that the default setup for injector timing is batch fire every 180 crank degrees ( fourstroke car engine ), this timing is random every time the engine is started. Once started it stays constant, but next time you start it will locate somewhere else. You can imagine the issues this caused, trying to tune this type of setup was impossible and it took a while to sort it out. I ended up making a device to strobe the injectors on and off points. Link's experience with twostroke injection has only been with snowmobile engines injecting into the intake ( an electronic carburetor ) where injection timing seems to be less important. You can appreciate I've put a lot of time and thought into this project.

How hard was it nail down tuning? Well it's still happening, some of the problem has been the computer setup as stated above and some the ethanol fuel I'm running ( too many new things at once ). Ethanol has the odd requirement for more fuel above 70 / 80 degrees C ( engine temp ). Water cooled engine you would never notice. Air cooled, at 120 degrees it becomes very lean so more fuel is needed. This is were the computer is soo good as it can easily be setup for this. This was always the problem with the MFI system I had previous. Very rich cold and early in the race only to come right at about two laps in, very frustrating! Now we can fuel it so the engine never sees 120 C.

[136kg136ps]

What increase in air volume will there be with the fuel being injected downstream of the 24mm restriction and how much power does ENGMOD2 suggest it will add ? EFI seems a win win given that restriction.

[TZ350]

What increase in air volume will there be with the fuel being injected downstream of the 24mm restriction and how much power does ENGMOD2 suggest it will add ? EFI seems a win win given that restriction.

Good question and I am sure EngMod2T can amswer it, but so far I have not gone to much effort to compare simulated differences between a carb and down stream fuel injection, but I have looked at the effects of bigger carbs and plenums.

Sure, by reving to the moon, there are engines that make big hp with a 24 carb. But EngMod2T shows there are better gains and mechanical safety to be had by fattening the torque curve at lower rev's and this requires more airflow, ie a bigger carb or something clever.

Also, although I should check this on the dyno by trying the 30mm carb in another back to back test. I believe the 24mm carbs restriction is contributing to my over rev deto problem.

I had fuel dropout problems and lubricating doubts before when I first tried the plenum. But now I see EFI allowing me to re visit the plenum idea as a way to negate any restrictive effects of the 24mm carb and increase the air flow through the inlet system.

[TZ350]

I will see if I can find some video of the plenum and carburettor.



First ever Startup.



A quick blits, not to far as its a bit dangerus going fast past the other units.

We ran it at the track but in the end shelved the idea as it suffered from a lot of fuel dropout leaving a cupful or so of very oily fuel behind in the plenum and this made us worry about whether enough oil was getting to the engine.

EFI could allow us to look at the plenum again.



The new plan, is to run the 24mm carb dry, run a ball inlet and TPS inside the plenum and fuel inject directly into the transfer ports.