ESE's works engine tuner

[teriks]

Attachment 298379Attachment 298380

If I take the fuel flow vs RPM graph and divide the fuel flow by RPM I get the red line which looks like the BSFC line.

All my fuel maps have started low and increased as the rpm goes up like the fuel flow plot but after dividing the fuel by RPM (Red Line) it looks like the BSFC line.

I may have been doing it all wrong and maybe the numbers on my Alpha-N map should decrees as the RPM increases.?????

http://ecotrons.com/files/Small%20en...20-%20v2_4.pdf

“LOAD” by definition is the actual air mass charged into the cylinder divided by the ideal air mass that could be filled into the cylinder.
What is the ideal air mass?
When you have your cylinder fully filled with fresh air at sea level (barometric pressure = 1 bar), and at the temperature of zero degree C (air temperature = 32 F), the mass of the air in the cylinder is the ideal air mass.

“LOAD” tells the ECU how much fuel is exactly needed for the desired air-fuel-ratio. Because you can only calculate the fuel quantity, if you know how much air is in the cylinder.

Our system let you map the “LOAD” out of TPS/RPM table, and then the load is used everywhere else as the base inputs (fuel, ignition, lambda, etc). Why?
Because LOAD is the most representative physical variable for air charge in the cylinder. Throttle position is not even proportional to the air mass. It has a non-linear relation to the air mass (if you know some math).

LOAD is normalized against the air temperature, and altitude, and pressure. It is then multiplied by those factors with correct physical models.
The way to calibrate the LOAD mapping is similar to the “volumetric efficiency” table. The best way is to use an engine dyno. If not, use a wideband controller, and if not, use the narrow band O2 sensor to do “estimations”.
At certain throttle position, and RPM, tweak your LOAD output, until you have a good AFR.
This is what auto industry called “Alpha-N” method.

Note: again, do NOT tune your LOAD table when engine has not been warmed up! Only do that after the engine is fully warmed up (example,ECT >= 50C).

After a quick look in the ecotrons tuning manual Id say that the LOAD values should reflect your fuel flow graph.
Now, keep in mind that I have never fiddled with fuel injection, only been dreaming about a system small enough for my stuff...

EDIT: Newermind, its really late here, and the more I read the more confused I get...

[TZ350]

--“LOAD” by definition is the actual air mass charged into the cylinder divided by the ideal air mass that could be filled into the cylinder. “LOAD” tells the ECU how much fuel is exactly needed for the desired air-fuel-ratio. Because you can only calculate the fuel quantity, if you know how much air is in the cylinder. Our system let you map the “LOAD” out of TPS/RPM table,""--

Thanks Teriks, that actually makes sense...... it looks like I had become focused on fuel when in fact Ecotrons actually mean the numbers on their map is all about air and not fuel.

From EngMod ... ""CHARGING EFFICIENCY. The mass of fresh charge trapped in the cylinder during scavenging divided by the mass of atmospheric air which fill the entire cylinder volume when the piston is at Bottom Dead Center. It is equal to the Trapping Efficiency times the mass based Scavenge Ratio ( nearly equal to the Scavenging Efficiency ).""

But I think Ecotrons is expecting a 4T where its virtually direct injection into a trapped volume and not a 2T where there is a lot of scavenge air lost out the exhaust port. so I might be better making my map more like the delivery ratio.

From EngMod ... ""DELIVERY RATIO. Mass of fresh charge supplied to the cylinder during scavenging divided by the mass of atmospheric air which would be contained in the swept volume ( not the trapped swept volume ) of the engine.""

I think the delivery ratio better represents the air mass I need to mix fuel with, but if I had a direct injection system like Orbitals then I would only need to look at the charging efficiency curve. Because with Orbitals direct injection there is no need to waste fuel on the lost scavenge air.

Red line "Charging Efficiency" ... Black line "Delivery Ratio" which I think is trapped air charge plus wasted scavenge air.

I will base my next Load Based (Alpha-N) mapping attempt on these air delivery ratio curves that I simulated using EngMod2T .



The good thing is, the Beast more or less runs OK in the 2 to 8,000 rpm range, so I have a good starting point.

[RomeuPT]

Hello Everyone.

Sorry for a bit of offtopic, had a problem, and don't know the cause...

After riding my nsr engine with RS cylinder, piston and other mods for about a hour or two, the bike started to make a "cracking" noise when the engine stopped. Also does it sometime when on idle, it's scary, seem the engine is breaking apart :S
Also when pulling the bike by hand with the engine stopped in six gear It could be heard some sort of beating when the piston start's the compression stroke.

I checked everything and find nothing unusual, I quited for a weak, then changed for older piston and cylinder and the noise vanished. Then the old piston on the new cylinder, nothing wrong.
Inspected the piston and I did find the upper edge of the ring grove a little worn where the piston is exposed to the exhaust port mostly. Also the ring is slightly sticked at this side, but that happens frequently and does not cause scary noise.

What is happening?

A size domed top piston for Honda RS 125, and 97 Honda rs cylinder, the bike start's very wheel, and pulls fine

[TZ350]

Does the new piston have an offset piston pin (it can be 1-2mm) and if it has, is the crank rotating in the correct direction for the offset?

An offset pin among other things helps reduce the mechanical piston slap noise as it passes TDC and BDC but if its on the wrong side for the direction of crank rotation it amplifies the noise of the piston slapping over from/to the thrust side of the cylinder.

Get the piston pin offset wrong and the motor can sound very rough. Also the cylinder bore center line can be offset from the crank center for the same reasons as pin offset.

[TZ350]

... the more I read the more confused I get...

Yes ... me too. 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.


Volumetric Efficiency – VE table

Volumetric efficiency is probably the most important characteristics of an engine. It determines how efficient the engine is sucking the air into the cylinder.

"Volumetric efficiency, dependent on MAP sensor and RPM" ; this is the fundamental calibration map of an engine, also called "speed-density" method.

It determines the commanded fuel at different manifold pressure and RPM. Basically, the volumetric efficiency determines the fresh air amount in the cylinder, and therefore the fuel needed for optimized AFR.


LOAD based Alpha-N system

For two-stroke engines, the default fuel mapping is Alpha-N method, "RAM_MAP_LdTp_Tps_N", so if you want to calibrate the fuel quantity for a 2-stroke engine, you just modify the LOAD table only.

"LOAD" is not the throttle position, because you can have different air mass in the cylinder at the same throttle
position.

"LOAD" by definition is the actual air mass charged into the cylinder divided by the ideal air mass that could be filled
into the full cylinder.

"LOAD" is a relative value, in percentage, unit-less.

"LOAD" tells the ECU how much fuel is exactly needed for the desired air-fuel-ratio. Because you can only calculate the fuel quantity, if you know how much air is in the cylinder.

TPS based LOAD mapping

Once you know what the "LOAD" is, you can tune the TPS based load mapping. This is called "Alpha-N" model by the auto industry.

Our system do not let you map the fuel pulse width directly out of the TPS / RPM table, because it is too coarse, and it is affected by too many factors (temperatures, altitude, speed, AFR, etc.).

The way to calibrate the LOAD mapping is similar to the "volumetric efficiency" table. The best way is to use an engine dyno. At certain throttle position, and RPM, tweak your LOAD output, until you have a good AFR.

Some EngMod2T definitions.

DELIVERY RATIO.
Mass of fresh charge supplied to the cylinder during scavenging divided by the mass of atmospheric air which would be contained in the swept volume ( not the trapped swept volume ) of the engine.

CHARGING EFFICIENCY.
The mass of fresh charge trapped in the cylinder during scavenging divided by the mass of atmospheric air which fill the entire cylinder volume when the piston is at Bottom Dead Centre.

TRAPPING EFFICIENCY.
The ratio of mass of delivered charge which has been trapped to the total mass of delivered charge. Remember that some of the latter exits the exhaust port before combustion starts, ie during scavenging.

Dratio Black line: DELIVERY RATIO
Ceff Green Line : CHARGING EFFICIENCY
Teff Red Line : TRAPPING EFFICIENCY

Attachment 298284

Now as you can see, not all the mixture that gets delivered actually stays in the cylinder long enough to be trapped there when the exhaust port closes. But with a carb all the "Delivered" air has had fuel mixed with it.

This is how I understand it. The black line is the air drawn through the motor by the pipe etc, some is lost out the exhaust port so the green line represents the amount left in the cylinder after the pipe has finished scavenging the cylinder and the red line is what has finally been trapped on the compression stroke with the help of the plugging effect of the pipe.



From Ecotrons ... "LOAD" by definition is the actual air mass charged into the cylinder divided by the ideal air mass that could be filled into the full cylinder. "LOAD" is a relative value, in percentage, unit-less.

But Ecotrons definition looks more appropriate to a 4T as a lot of the inducted air mass (black line) in a 2T gets lost out the exhaust port. And for a 2T the Charging (green line) is not as useful for developing a Load based map as it would be for a 4T. If the 2T had direct injection then I imagine the Trapping Efficiency (red line) would be the one to use.

With a carburetor all the inducted (Delivery Ratio (black line)) air gets fuel mixed with it. So I guess that is where I have to start. I can refine it later by timing the injection end point (and hence its start point) to minimize the fuel lost with the wasted scavenge air.



It looks like the Load-TPS (Alpha-N) map cell values should be an array of percentages that start by following the black line and at 8,500 rpm and TPS 100% the cell value would = 100% and for TPS 40% the cell value would = 80%.

[speedpro]

Is it possible to map the injection start or finish point or is it a single value? Being able to map it would seem ideal as you could avoid injecting fuel into air that is not trapped in the cylinder. Given that it seems likely the injectors could end up running at a high duty cycle it may be of little benefit as any air ingested at high load and rpm will have had fuel injected into it.

[TZ350]

Is it possible to map the injection start or finish point or is it a single value? Being able to map it would seem ideal as you could avoid injecting fuel into air that is not trapped in the cylinder.

Yes, with the Ecotrons system, on another map, its possible to map the injection end points and I think that will be very useful as Flettner has been able to reduce his fuel consumption that way. But first I have to just get the basics working and I am finding that harder than I thought it would be.

[Flettner]

This looks way complicated?
The YZ was tuned ( seat of the pants ) in about an hour ish riding around the yard. BUT now we have changed the YZ system to run a third injector ( in the crankcase, pointing at the bigend ) and we seem to have buggered up the settings. It's kind of staged but something is not happening as it should. I'm trying to convince Wayne to add extra wires at the injectors so we can " see " whats happening with my injector timing light.
The Link has it's limitations in 2T mode. I can set the ECU up as a 360 degree fourstroke twin and use two outputs ( joined to the same injectors, injectors will fire every 360 degree cycle ). This will need a cam sensor, I'll have to set up another trigger at half crank speed for this to happen but this will allow me to access ALL the settings available. A pain in the arse but Link will not finish the software needed to sort the 2T side out. Said there was no demand, might have a point there.
The F9 has been running a big fat carb this season ( on petrol ), but it's going back to EFI again this next season ( carb has been seen by all this year, no one will suspect a thing ) I'll be setting this up as above to test the system ( 360 degree fourstroke twin setting ).

[RomeuPT]

Does the new piston have an offset piston pin (it can be 1-2mm) and if it has, is the crank rotating in the correct direction for the offset?

An offset pin among other things helps reduce the mechanical piston slap noise as it passes TDC and BDC but if its on the wrong side for the direction of crank rotation it amplifies the noise of the piston slapping over from/to the thrust side of the cylinder.

Get the piston pin offset wrong and the motor can sound very rough. Also the cylinder bore center line can be offset from the crank center for the same reasons as pin offset.

Thanks for the reply.
The piston have no offset. The cylinder I don't know, but I think is not.

The thing is, this noise didn't start until I used this piston/cylinder combo for about an hour or two.
By hand the bike have compression going in front, going backwards have almost nothing. With the old piston feels the compression both ways...

I had an old RS cylinder running with a KX125 namura piston, that runned for a year playing around. Now that I really spended money with a real combo I got this

[Frits Overmars]

By hand the bike have compression going in front, going backwards have almost nothing.

That happens when the piston ring is stuck in its groove, at the exhaust side. If you turn the crankshaft backwards, the con rod will push the piston against the bore opposite from the exhaust side, lifting the stuck side of the piston ring away from the bore.

[speedpro]

He did mention a stuck ring. The cause of the stuck ring could also be the cause of the noise. If the deck height of that piston is greater than the other pistons it may be just touching the head enough to flatten the edge of the piston enough to trap the ring. A look at the head and top of the piston should give us a clue. If the squish area adjacent to the ex port is clean compared to the rest of the squish that tells you it is closer. It wasn't mentioned but if the deck height is different and machining was required on the cylinder top surface maybe it wasn't machined square.

[F5 Dave]

Or the head not doweled to the barrel properly and head chamber offset in use. Bolt it up loosely off the cases and look up the bore and try move the head around. Should be unlikely to be a problem on RS parts but who knows their history?

[F5 Dave]

Ok my problem; along standing issue of ring seal and bore wear. MB100 running KT100 piston. Both steel bore std so ring are compatible.

There was an. Issue when the. Rod continued on its path extending the inlet port to the bottom. As I've case reeded it I've glued some ally in the hole to make a boost port fully formed. So I do have a question that this lack of support at the bottom could be affecting the bore at the top. But I've never had the ally crack it's epoxy or fall out and the barrel is complete for a cm below the ports so should be ok.

anyhoo I always get a polished bore above the ex and the boost port. Always wears there and a hone won't bring it back round easily. The area is scooped out above the exh the longer it runs. I'm also seeing scooping above the boost port. Running 20:1 castor oil. Ex port is 68% width , heavily chamfered and very oval and symmetrical. Ring seal has never gotten better than 25% (often much worse) despite using torque plates and heating to operating temp before honing. KT runs say 8% as comparison . Barrel is water cooled now.

so the KT piston runs it's ring peg centrally at the back over the open back boost port which we all knows works in many engines from where I first saw it in the 256. A difference I'm wondering is that the Rotax and everything more modern is plated. Contemplating one more go last oversize moving the peg to between boost and transfers. Thoughts?

[wobbly]

The rod angularity is at a max 1/2 way down the bore so if the lower skirt isnt supported properly the piston will cock over,dragging the ring edge into
the bore and creating the wear pattern.
Dump the 18th century fish and chip cooking oil and get something in there that has at least a modicum of film strength.

[TZ350]

I always get a polished bore above the ex and the boost port. Always wears there and a hone won't bring it back round easily. The area is scooped out above the exh the longer it runs. I'm also seeing scooping above the boost port.

Thoughts?

Sometimes I get this too and wonder if it could be bore wash from un vaporized fuel in the scavenge stream washing the oil away???? ...