Aftermarket VS motronic management

[prj]

P.S.
There is enough information on this forum and www.motronic.ws to find fuel and ignition. By comparing different software you can find limiters, and the basic stuff you need to tune in the boost chip, tracing function of the emulator will help you find the axes. There is even some pictures with locations of maps posted...
You can tune your car easily to 370-380hp using an emulator, datalogger and the information already present.

But most people don't even make that effort - they don't try. And if you don't want to try to tune using the available info, then why are you complaining that the ecu is untuneable, everything is impossible and bad and info secret?
There's enough info to get started, and people will help you once you show that you understand basics of tuning and have used the available info to tune your car.

[UrS4boy]

prj: Looking at the 3D plots that show up in that Motronic website (thanks for the link, BTW), it seems that there are some strange data points ("bumps" or "holes" in the plot). To me that data should have been smoothed out with some form of "Surfer" equation that makes the graph a continuous smooth plot rather than a series of discrete points. The graphs give me an idea why there are strange issues, e.g. the drop off at 4400 in this dyno plot from an RS2'd UrS6 running Dahlback/MTM software:

[A80Avant]

i had visited in the past this website and indeed it was fairly difficult to understand. As you say, without the emulators you probably have no idea what's going on.

Trouble is, when i started in vems, there was no solution to motronic above 500hp and now there is. So my best scenario is once im happy with my VEMS setup(as mentioned before) i may try the motronic tune with the new maf to see if motronic will be better in fuel economy and perfomance as well.

[prj]

prj: Looking at the 3D plots that show up in that Motronic website (thanks for the link, BTW), it seems that there are some strange data points ("bumps" or "holes" in the plot). To me that data should have been smoothed out with some form of "Surfer" equation that makes the graph a continuous smooth plot rather than a series of discrete points. The graphs give me an idea why there are strange issues, e.g. the drop off at 4400 in this dyno plot from an RS2'd UrS6 running Dahlback/MTM software:

I can assure you that all maps in our software are nice and smooth.
Always take everything with a grain of salt
The reason there are fluctuations is completely different - there are many actually - knock, wrong boost control tuning, wrong knock tuning etc.

Trouble is, when i started in vems, there was no solution to motronic above 500hp and now there is. So my best scenario is once im happy with my VEMS setup(as mentioned before) i may try the motronic tune with the new maf to see if motronic will be better in fuel economy and perfomance as well.

The only reason it would be better with fuel economy/performance is because your VEMS is tuned wrong.
All it does really is drive injectors, coils and N75 - not really anything else related to performance.
VEMS can do exactly the same thing, so there is no reason at all why it should have worse performance be the definition of "performance" fuel economy, or torque. You need to tune your ECU on a dyno instead of "butt feeling"

[A80Avant]

to that i agree!

however i was told before that when tuning with a maf there is more accuracy involved, however unless i go on a dyno, i wont know.

by the way, i notice that when the wideband is not doing minor corrections for various situations(heatsoak,too hot,too cold weather etc), if i leave the wideband offline, the fueling map cannot alone be as accurate on all occasions.
Now you say that on motronic and during cruise you keep the narrow band off and get better fuel economy through the MAF measurements.
Does motronic compensate for other fluctuations, and in what way? What do you do when you tune the car and you do not have those different circomstances?

eg. you tune someone's car at 0-10deg IATs. What will that car run on when the iATs are 35-40C? do you use the table by 'best guess' or do you recheck the tune when the summer comes?

[prj]

IAT doesn't change THAT much when you are off boost cruising.
And MAF is very accurate, you just tell Motronic target Lambda.

The reason I keep narrowband off is because it's only useful for forcing 14.7 AFR. Useless for everything else. Best economy is closer to 16 AFR. Narrowband is purely treehugger stuff in M2.3.2. ME7 is smarter in that it uses those trims at WOT as well.
And of course MAF based systems are always more accurate - they measure cylinder filling directly, instead of relying on guesswork, like speed density systems - this is the reason many OEM's use mass-flow as well. It's more resistant to different circumstances.

Your speed density system runs closed loop WBO2 though - so what's the problem?
I can add closed loop WBO2 to Motronic as well (enough inputs for that), but no need. It's accurate enough as-is.

[A80Avant]

thats what i was saying, if you can add a wideband on the motronic, thats even an added safety/accuracy.

is it possible for a mAF to get damaged in a sense that would stick the target lamda to lean? if so, the wideband might be a good addition to the system. If not, then just forget i mentioned it

[prj]

I said before - running too lean in the range where the narrowband is used is MUCH better than running too lean on boost where it is not used.
If the MAF is damaged you'rе screwed either way.

And you can just get a WBO2 gauge and look at the AFR.
Motronic couldn't act as a WBO2 controller anyway, you'd need a box to generate a 0-5V signal - if you have that anyway - you will see if your AFR is off, and if your MAF is working okay, then it's accurate enough, so that WBO2 is not needed.

EDIT:
Short version:
MAF is OK = WBO2 not needed
MAF is screwed = You are screwed anyway, because Motronic wouldn't work purely from WBO2, and if you have WBO2 you will see by the numbers that something is wrong and replace the MAF anyway.

I have thought this through pretty well... not worth the effort adding EGT or WBO2 feedback to it, since you always need a separate box on which you can just look.

[mouse]

eg. you tune someone's car at 0-10deg IATs. What will that car run on when the iATs are 35-40C? do you use the table by 'best guess' or do you recheck the tune when the summer comes?

IAT doesn't change THAT much when you are off boost cruising.
And MAF is very accurate, you just tell Motronic target Lambda.

That was my concern too - 35 - 37C is just another hot summers day over here and we always get a few over 40C. I have myself previously measured temps in the airbox climbing over 60 is slow traffic and stopped at lights. . and thats before the turbo.

I was thinking the concern would not be so much off boost cruising but at 70-90% throttle where there would be plenty of boost but standard motronic would still use lambda (right?)... But thinking about it even the stock ecu turns off lambda at WOT so motronic can obviously adjust for these types of temps without lambda anyway.

[prj]

I was thinking the concern would not be so much off boost cruising but at 70-90% throttle where there would be plenty of boost but standard motronic would still use lambda (right?)...

No, it doesn't. It doesn't use narrowband lambda as soon as you start accelerating, even if very lightly.
If it was regulating mixture to 14.7 on 90% throttle you would be buying a new engine every month.

But thinking about it even the stock ecu turns off lambda at WOT so standard motronic obviously adjusts fror these types of temps without lambda anyway.

No, it's not at WOT, it's nowhere near WOT.
The only time it uses narrowband o2 feedback is when you are driving in a straight line with fixed throttle without acceleration.
Hell, if you go up a steeper hill it turns it off already...

[A80Avant]

there is no problem with the motronic on boost, because it doesnt use lamda anyway. However when the IAT gets colder the air gets denser and the fuel needs to be higher in order to keep a target lamda. The opposite occurs if the IAT is hotter. The air is less dense and less fuel is needed to achieve for example a lamda target of 0.80. I presume motronic can do that fine by getting the MAF reading.

[prj]

there is no problem with the motronic on boost, because it doesnt use lamda anyway. However when the IAT gets colder the air gets denser and the fuel needs to be higher in order to keep a target lamda. The opposite occurs if the IAT is hotter. The air is less dense and less fuel is needed to achieve for example a lamda target of 0.80. I presume motronic can do that fine by getting the MAF reading.

Yes...

[A80Avant]

That is another thing to consider then, as part of safety, people should fit an EGT sensor +/- a wideband sensor as the single most important thing when using the motronic is the MAF, so any subtle or bigger problems with that, will need to be addressed soon. In any case an EGT sensor and a wideband will be needed for tuning, so may as well have them.

ON the other hand, on aftermarket ECUs and people running closed loop lamda, the most important thing is the wideband, as if it gets damaged and stuck on a lean reading, then it can potentially keep it lean all the way and then boom! But the way around that, which many tuners do is not to use the lamda on boost anyway.

[prj]

On a stock car EGT is not really needed...
With bigger turbo yes, but not really with K24-7000.

Anyway, don't be obsessed with the narrowband O2. As I said before, in M2.3.2 it is purely for treehuggers so your car generates less NOx.
There is no reason whatsoever to keep a car at lambda = 1 other than emissions, and that only if you have catalytic converters.

If you want to keep O2 feedback, then it's possible to replace the narrowband lambda with a WBO2 and generate a simulated O2 signal to Motronic with a switchpoint of around 15.8 AFR.
But there's no real point. If you do this without re-tuning the fuel map, you might start getting adaptation errors, plus lambda range should be shortened a bit in the s/w or you might get knock.

[Rocco]

i like these reads