Hacking the Motronic ECU (Audi RS2)

[Dybro]

And you still don't understand, that you need to change injectors if you are going to use E85, because you will run out at 6000 rpm with more than a 30% blend.

For good sake. Understand what I'm writing. I DON'T run it on E85 because it requires much more fuel! That's why I maximum use 20% ethanol.

Also, lambda in motronic 2.3.2 is mainly an afterthought. It is only used on light cruise, and if it is disconnected the car still runs perfectly fine to the mapped AFR.

Do you mean that that it doesn't have an overall lambda-fuel-correction?

There is no TPS based "acceleration enrichment"

Well.. then my engine behavior makes sense. Thanks

[prj]

There is no TPS based "acceleration enrichment". Everything is mapped.
And you still don't understand, that you need to change injectors if you are going to use E85, because you will run out at 6000 rpm with more than a 30% blend.
Also, lambda in motronic 2.3.2 is mainly an afterthought. It is only used on light cruise, and if it is disconnected the car still runs perfectly fine to the mapped AFR.

Of course this is if you don't screw with injectors or the fuel!
If you do, you need to change the injector constant for it to run correctly, as with all MAF based systems.

[Dybro]

Because what you have written shows that you do not understand mass-flow based EFI.
This has nothing to do with Motronic per se.
And regarding fuel - it is obvious to anyone with tuning knowledge, that in case of E85 more units of fuel are needed per unit of air than with gasoline.
Thus, if you blend fuels, you are effectively reducing the injector size on your car. A system with WBO2 feedback will be able to compensate with fuel trims up to a certain extent (but it will still run badly). M2.3.2 does not have WBO2 feedback. In fact, a Mass-Airflow system does not even need it, it is very precise without. As long as you don't try messing with the injector size or the fuel.
This has nothing to do with the tuning of your engine or motronic or how a tuner did his job - it is tuned to run on gasoline, by adding ethanol to it, you are obviously running lean, but because you do not seem to understand EFI, you blame it on motronic or on the tuner, which is just ridiculous.
This is the reason for my remark.

It is possible to run a car on E85 and Gasoline with motronic just by having a single switch. Obviously blends won't work very well. Another option is to have a switch for the boost and run with an emulator connected at all times. Then it is possible to have an infinite amount of maps, although you would need to be pretty handy with electronics to wire it all up.

I do know how MAF efi works, how the MAF-sensor works, that ethanol contain less energy, and also that the m2.3.2 don't have wbo2 .
But I don't know the exact logic of the long and short therm fuel correction and the transient fuel enrichment in motronic. If you could tell me that it would be helpful.
Why didn't mention the NBO2 fuel correction as it is the only way it can compensate for changing energy-density of the fuel??

You obviously haven't understood what I have been trying to tell.
But there's no reason to argue back and fourth about who knows what and how much - it's just waste of yours and my time.

If you can tell some details about the m2.3.2 TPS-based transient fuel enrichment, the long and short therm fuel-correction it would be helpful
Thanks

[prj]

How can you assess how much I know about ethanol, combustion engines and lambda?! You obviously don't know which education i have!! But I don't know so much about the motronic and how to modify it.

Because what you have written shows that you do not understand mass-flow based EFI.
This has nothing to do with Motronic per se.
And regarding fuel - it is obvious to anyone with tuning knowledge, that in case of E85 more units of fuel are needed per unit of air than with gasoline.
Thus, if you blend fuels, you are effectively reducing the injector size on your car. A system with WBO2 feedback will be able to compensate with fuel trims up to a certain extent (but it will still run badly). M2.3.2 does not have WBO2 feedback. In fact, a Mass-Airflow system does not even need it, it is very precise without. As long as you don't try messing with the injector size or the fuel.
This has nothing to do with the tuning of your engine or motronic or how a tuner did his job - it is tuned to run on gasoline, by adding ethanol to it, you are obviously running lean, but because you do not seem to understand EFI, you blame it on motronic or on the tuner, which is just ridiculous.
This is the reason for my remark.

It is possible to run a car on E85 and Gasoline with motronic just by having a single switch. Obviously blends won't work very well. Another option is to have a switch for the boost and run with an emulator connected at all times. Then it is possible to have an infinite amount of maps, although you would need to be pretty handy with electronics to wire it all up.

Either way, 99% of what you have written has nothing to do with Motronic at all, so this is not the correct thread to post it...
EspenW runs his car on ethanol with aftermarket ECU management - he can probably give some tips, but open a separate thread for that.

[Dybro]

You assume everything, and you know very little....
Please learn about lambda, about ethanol and about internal combustion engines in general.

How can you assess how much I know about ethanol, combustion engines and lambda?! You obviously don't know which education i have!! But I don't know so much about the motronic and how to modify it.

If you have poor throttle response during transients, then your timing is wrong. This is assuming the rest of your car is in good order, which I doubt.
If you blend ethanol without re-tuning, your car will not run properly.

It actually runs great on low ethanol percentage up to about 20% - much higher did trigger the max. lambda correction. But the throttle response gets poor and with a smell of alcohol(only by revving the engine and cold cats.), which also makes me believe it that the transient fuel is to lean. Unfortunately I don't have a WB lambda which can prove or disprove my theory.
Yes I know that it is to bad that I don't have one yet..

[prj]

Well.. it feels something like a 1/3 second. that's why I think the throttle-response is lazy. If I run it on E10 or E15 mix it get worse witch make me think that transient-fuel is to lean - even for pure gasoline..... (I don't have a wide-band probe yet)

But it has an unknown chip in it. Maybe the tuner didn't do his job properly.

You assume everything, and you know very little....
Please learn about lambda, about ethanol and about internal combustion engines in general.

If you have poor throttle response during transients, then your timing is wrong. This is assuming the rest of your car is in good order, which I doubt.
If you blend ethanol without re-tuning, your car will not run properly.

[newsh]

Exactly. I also mentioned that in an earlier post

Except..

Transient fueling is very good on stock - not in my AAN. Mostly it get to little fuel (a 1/3 second delay) if I step on it fast during idle or fast idle...

[Dybro]

So actually its not stock..

Exactly. I also mentioned that in an earlier post

.......
improve the throttle response(really think it's "lazy", and it is already chip-tuned)

[newsh]

So actually its not stock..

[Dybro]

lol... idle...
And you have a datalogger with at least 1/3 second resolution as well? I would really like to see a log.

During *transients* fuel delivery is perfectly fine. There are no lean spikes.

Well.. it feels something like a 1/3 second. that's why I think the throttle-response is lazy. If I run it on E10 or E15 mix it get worse witch make me think that transient-fuel is to lean - even for pure gasoline..... (I don't have a wide-band probe yet)

But it has an unknown chip in it. Maybe the tuner didn't do his job properly.

[prj]

Proper ign. timing is power - year sure.

Transient fueling is very good on stock - not in my AAN. Mostly it get to little fuel (a 1/3 second delay) if I step on it fast during idle or fast idle...

lol... idle...
And you have a datalogger with at least 1/3 second resolution as well? I would really like to see a log.

During *transients* fuel delivery is perfectly fine. There are no lean spikes.

[Dybro]

Transient fueling is very good on stock.
Fueling is not power. Spark is power.

This is really basics. Pick up a book.

Proper ign. timing is power - year sure.

Transient fueling is very good on stock - not in my AAN. Mostly it get to little fuel (a 1/3 second delay) if I step on it fast during idle or fast idle...

[prj]

by improving the throttle-response I mean tuning the tps-based transient fueling and not incising boost at part-throttle

Transient fueling is very good on stock.
Fueling is not power. Spark is power, and fueling is only a tool to combat detonation.

This is really basics. Pick up a book.

[prj]

well, that is true in one sence, but when you have the external wastegate and a stiff spring, you are trying to allow a big turbo to build up boost as fast as mechanically possible and therefore one of the ways to do that is to be able to allow for a fast TPS response as well.

It is not "fast TPS response". It just kills any throttle modulation.
And your logic is very wrong. The bigger the hotside, the softer the wastegate spring needs to be.
The required strength of the wastegate spring is inversionally proportional to hotside size (proportional to backpressure).
Thus, a smaller turbo, with a smaller hotside requires a stiffer spring to drive to high boost levels, than to drive a turbo with a larger hotside to the same boost level.

On VEMS you have 2 separate tables, one for TPS vs Boost and one for the boost curve itself(simplest way to control boost), otherwise you can still have a 3d map of boost vs rpm as well.

Boost vs RPM is needed, because compressor maps are not flat. By having a boost vs RPM table you are able to make more torque/hp.

I usually ask for 90% of rpm calculated boost when throttle is above 50% pressed, because on simple overtakes on low revs where the turbo is not kicking in due to lag, i want to be able to have a fast responce without having to go WOT all the time.

And what for is your throttle pedal? Just make the pedal travel shorter.
I am sure you would like a device like "sprint booster" if your car had an electronic throttle pedal. Going WOT is perfectly fine and then slightly letting off when too much boost starts to build. Not to mention, that you will get faster spool/more power this way, then trying to spool when the intake is strangled by the throttle.

Therefore on low revs, the turbo along with the N75valve is basicaly trying to keep the wastegate shut so that the turbo can build up the pressure fast.

And increase the backpressure, and stress the turbo more than needed and reduce fuel economy. But I guess none of those things are important to you.

I dont think this is causing any more stress to the turbo itself. I understand that keeping 50% TPS and asking for 2bar of boost is more stresfull, but usually when the turbo is in the rpm range that it can give me that boost i do use WOT.

You are just wrong on this one.

For me i think that having a more responsive TPSvsBoost allows for a more subjective and driver specific driving habit, and i do like it.On smaller turbos which spool faster it indeed may pose a bit more stress to it, it will surge more often, but i dont believe that it will extremelly alter the turbo's life

If you use a stiff spring, you are already severely reducing the turbo's life. If you use a stiff spring and basically flat TPS mapping, you are doing it even more.

Remember, the TPS mapping comes into play when boost pressure exceeds spring pressure only.

[Dybro]

by improving the throttle-response I mean tuning the tps-based transient fueling and not incising boost at part-throttle