MAF Scaling - Open/Closed Loop Fueling info

[steve99]

Originally Posted by drift86

I have a Takeda intake and I tried to do MAF scaling using the CSV file from the first post.

My LTFT was way off after doing this. (-16%)
http://www.datazap.me/u/drift86/maf-...log=0&data=1-6

LTFT was much more stable when using the standard stage 1 OTS v2.06 tune. (-4%)
http://www.datazap.me/u/drift86/stag...log=0&data=1-5


Maybe there are different versions of the Takeda intake and they scale differently? Mine is the newer version with the longer snout and I was running without the snorkel.

Old version:
http://www.tr3performance.com/wp-con...afe-intake.jpg

Newer version:
http://cdn.shopify.com/s/files/1/019...x1024.jpg?1279

that scaling was definitely from the old version, wich appeared to suffer from some turbulant air flow , suspect they have fixed this in newer version of the intake hence scaling is much different.

you will have to scale the new one from scratch with VGI utility its not hard.

[Skorov]

After a bunch of fiddling around with the MAF scale, I get a result like this...

http://www.datazap.me/u/skorov/maf-scaling-1

My LTFT is good, about +/- 3.9%. But my STFT are still out by quite a lot. Up to +/- 29%

I want to make sure this part is right before I go on to scale OL portion.

Is this a decent result? If not, what can I do to bring the STFT closer to the 0 point.

Thanks!

[Kodename47]

Originally Posted by Skorov

After a bunch of fiddling around with the MAF scale, I get a result like this...

http://www.datazap.me/u/skorov/maf-scaling-1

My LTFT is good, about +/- 3.9%. But my STFT are still out by quite a lot. Up to +/- 29%

I want to make sure this part is right before I go on to scale OL portion.

Is this a decent result? If not, what can I do to bring the STFT closer to the 0 point.

Thanks!

STFT will always fluctuate, however what you're looking to do is ensure that the fluctuations are similarly equal over/below 0%. Yours are. There's not much you can do to reduce fuel trims and that's why they are there.

To further reduce them you could work on PI/DI differences and fine tune your engine load compensation table. You have no need to do it though.

[Skorov]

Originally Posted by Kodename47

STFT will always fluctuate, however what you're looking to do is ensure that the fluctuations are similarly equal over/below 0%. Yours are. There's not much you can do to reduce fuel trims and that's why they are there.

To further reduce them you could work on PI/DI differences and fine tune your engine load compensation table. You have no need to do it though.

Cool! Thanks a lot. Very helpful a always. :-)

I'll work on the OL part now.

[Wayno]

You can minimise the dip by taking advantage of the Engine Load Limit tables.

This is absolutely required on AT, but these values should also help on MT. On AT you still end up with -6% to -8% dip at 3.2V, MT you might not end up with any dip in the MAF scale there at all doing this.

Note - you have to rescale the axis so you can hit the load limit up to 4000, then not hit the limit at 4000.

Originally Posted by DocWalt

So after going through that work suggested by Kodename and Steve I got a couple of nice WOT logs. Some minor knock correction, but no IAM drops and I'm still on mediocre 91 octane gas.

http://datazap.me/u/docwalt/04-11-15...zoom=1249-1338

http://datazap.me/u/docwalt/04-11-15...zoom=2370-2504

The MAF changes I came up with based on those logs gives me a curve like this:


I guess I'll still have the little bit of a rich spot with the slightly lean spike. Unsure what's going on there, but based on my virtual dyno results from earlier it's not causing a loss of power.

Thank you for the help guys!

[DocWalt]

Originally Posted by Wayno

You can minimise the dip by taking advantage of the Engine Load Limit tables.

This is absolutely required on AT, but these values should also help on MT. On AT you still end up with -6% to -8% dip at 3.2V, MT you might not end up with any dip in the MAF scale there at all doing this.

Note - you have to rescale the axis so you can hit the load limit up to 4000, then not hit the limit at 4000.

Neat, thanks! I've noticed a tiny bit of a bump in power delivery going from closed to open loop at low-ish throttle. Likely because of that dip in the MAF scale. Thanks for the post!

[Kodename47]

@Wayno can you explain what the point in capping the engine load in those tables? I have a tendency to set them high as to not hit them and don't really understand what benefit it has to do otherwise.

[Wayno]

Originally Posted by Kodename47

@Wayno can you explain what the point in capping the engine load in those tables? I have a tendency to set them high as to not hit them and don't really understand what benefit it has to do otherwise.

On FI that might make sense. On my car, you can see it goes lean when it hits the load limit, correct? Then at 3k it goes super rich. You can throw a tonne of maf correction at it, but there's a problem with that because the car will run lean at other loads in the same maf cell. Example say 5k rpm, 20pc throttle might be a whole 1 AFR leaner than target. So i took advantage of the load limit functionality to lean that area up for me.

Another solution i thought of as a workaround would be edit the target throttle plate table so it's just not possible to over load. Using the load limits is better though i think as that 3k-4k region isn't over loaded, really don't know why it's so rich on AT.

I still have -8% in that 3.2V cell compared to OTS

[xxBrun0xx]

Hey all,

A friend just got a 3" Perrin intake. Luckily, Perrin gives you their base MAF scaling on their website, which makes updating him pretty easy. While playing around with the OFT files, though, I noticed the MAF scaling seems very different from stock.

Attached pics are of stock vs OpenFlash scaling. The OF scaling is identical on all A00C and A01C roms. Did Shiv do this on purpose? Would imagine this would make your car run like shit.

Stock:


OFT:

[Kodename47]

Originally Posted by xxBrun0xx

Hey all,

A friend just got a 3" Perrin intake. Luckily, Perrin gives you their base MAF scaling on their website, which makes updating him pretty easy. While playing around with the OFT files, though, I noticed the MAF scaling seems very different from stock.

Attached pics are of stock vs OpenFlash scaling. The OF scaling is identical on all A00C and A01C roms. Did Shiv do this on purpose? Would imagine this would make your car run like shit.

Stock:


OFT:

That's not correct, be wary using ECUFlash as the definition is wrong for the OFT files and you could brick your ECU. That would explain the completely wrong values.

[steve99]

Originally Posted by xxBrun0xx

Hey all,

A friend just got a 3" Perrin intake. Luckily, Perrin gives you their base MAF scaling on their website, which makes updating him pretty easy. While playing around with the OFT files, though, I noticed the MAF scaling seems very different from stock.

Attached pics are of stock vs OpenFlash scaling. The OF scaling is identical on all A00C and A01C roms. Did Shiv do this on purpose? Would imagine this would make your car run like shit.

Stock:


OFT:

I think your using the wrong definitions for the oft files.

It appears your using ecuflash, the oft roms your using have had the calid adjusted and are actually B01C roms internally

Use the B01C romsand def that should work.

please read the tactrixecuflash link below specially the warning in red, else as @Kodename47 saays it will be a new ecu for you.

[xxBrun0xx]

Originally Posted by steve99

I think your using the wrong definitions for the oft files.

It appears your using ecuflash, the oft roms your using have had the calid adjusted and are actually B01C roms internally

Use the B01C romsand def that should work.

please read the tactrixecuflash link below specially the warning in red, else as @Kodename47 saays it will be a new ecu for you.

So you can just take the B01C definition and name it A01C.xml? Won't you then have issues reading/writing the stock A01C file?

Or do you mean I should be flashing the B01C rom to his car, not A01C because the A01C definition is still incomplete?

[Wayno]

Originally Posted by xxBrun0xx

So you can just take the B01C definition and name it A01C.xml? Won't you then have issues reading/writing the stock A01C file?

Or do you mean I should be flashing the B01C rom to his car, not A01C because the A01C definition is still incomplete?

Steve just said, and you even quoted him if you're not using openflash then flash B01C and use the B01C def.

[steve99]

Originally Posted by xxBrun0xx

So you can just take the B01C definition and name it A01C.xml? Won't you then have issues reading/writing the stock A01C file?

Or do you mean I should be flashing the B01C rom to his car, not A01C because the A01C definition is still incomplete?

At the start of the tactrix ecuflash post link below is a rom comatbiliy list

Cars which came with A01C are compatable with the updated B01C roms.

read this info here on OFT roms
http://www.ft86club.com/forums/showthread.php?t=79152



use the B01C rom and B01C def with ecuflash, check some tables to make sure everything matches and tables look good. you can flash B01C roms to A01C cars

if you unsure what is going on with oft roms and ecuflash then stop else you may brick your ecu. do some more reading.