Hacking the Motronic ECU (Audi RS2)

[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]

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...

[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.

[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]

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]

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]

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]

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]

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.

In a chipped car with stock head on petrol, at 6000 rpm and 1.1 bar boost injector duty is close to 90%.
Adding 20% ethanol to that (and remapping properly) will max injectors. 30% and you will get a lean spot, which is not a very good idea.

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

No, it doesn't. average/high load conditions are not affected at all by the presence of the lambda sensor.
On my car I have mapped it to only use lambda at idle/revving without load, so I can run 15.6-16 during cruise and still pass emissions.

[Dybro]

In a chipped car with stock head on petrol, at 6000 rpm and 1.1 bar boost injector duty is close to 90%.
Adding 20% ethanol to that will max injectors. 30% and you will get a lean spot, which is not a very good idea.

It's much the same I have in mind... I don't dare to rev it high with 0.8+bar boost while having too much ethanol in it.

No, it doesn't. average/high load conditions are not affected at all by the presence of the lambda sensor.
On my car I have mapped it to only use lambda at idle/revving without load, so I can run 15.6-16 during cruise and still pass emissions.

OK Thanks

[prj]

It's much the same I have in mind... I don't dare to rev it high with 0.8+bar boost while having too much ethanol in it.

In your case your injectors will not inject more fuel. Because your car is not mapped to do so.
This means, you won't max them out, but you will run leaner all the time. And yes, most noticeable will be when accelerating from light-load cruise, because motronic is mapped to have over 1.02 lambda during these conditions in stock form. With ethanol you will be getting even leaner. Torque starts to rapidly drop after approximately 1.09 lambda on these engines.

[Dybro]

In your case your injectors will not inject more fuel. Because your car is not mapped to do so.
This means, you won't max them out, but you will run leaner all the time. And yes, most noticeable will be when accelerating from light-load cruise, because motronic is mapped to have over 1.02 lambda during these conditions in stock form. With ethanol you will be getting even leaner. Torque starts to rapidly drop after approximately 1.09 lambda on these engines.

With the current chip it can deliver 1.3 bar boost. But I think it's way too risky with std. injectors

[prj]

I run 1.6 bar boost with standard injectors.
Injector duty cycle depends on RPM. The lower the RPM, the more time the injectors have to inject fuel...
You can log injector opening time in milliseconds from vag-com, and then use that information to calculate the duty percentage.

[Sir Buff]

Hi

Is the calculation of the rev limit correct for our cars as shown on this website?:

http://www.motronic.ws/revlimt2.htm

Rev Limit = ScaleFactor / RL1
Rev Limit = 983600 / RL1

[prj]

The info on that site is incorrect.
Not a single RS2 has a such limiter.