OFT Stage 2 UEL tune concern
 

I have been running stage 2 91 tune for a bit and concern about my LTFT and IAM. It's been roaming around 8% + LTFT lately and .5 to.75 IAM. I did not find any leak around my ofh header/o2 sensors. I currently have a TRD intake instead of factory stock. Do I need to rescale my maf sensor? If so, can anyone point me on how to go about doing that. Based on the data, is this tune reliable for daily driving?


Here is the data
http://www.datazap.me/u/iris-mm/86?log=0&data=1
Thanks

I didn't look at your log but I would suggest you check this thread by Steve99

http://www.ft86club.com/forums/showthread.php?t=71157

It's definitely not ideal with your IAM dropping that much and fuel trims being off. You're getting knock obviously to have your IAM drop. Something is off whether it's a leak, bad fuel, maf scaling off, is to be determind.

Hi Iris, you definitely need to rescale maf for starters. Without logging FLKC and FBKC (knock corr. on OFT), we won't know what knock events are causing IAM to drop/engine to go into coarse correction mode but as JB said, it's knockin'. Even with "stock maf location" intakes (Grimmspeed, your TRD) there is some variance in the overall flow of the unit and if you're seeing these kinds of fuel trims, chances are you will first need to rescale your maf.

Log the following parameters to re-scale maf and help identify/tune for knock:
(1) engine speed, (2) engine load, (3) MAF voltage, (4) STFT, (5) LTFT, (6) IAM, (7) Throttle, (8) AFR, (9) COMMANDED AFR, (10) IAT (Intake temp), (11) Knock Corr (FBKC), (12) FLKC

Take a mixed throttle/rpm/load log for around 30 minutes... try to avoid engine braking (decelerating in gear), idling, coming to a stop (backwoods roads work the best)

Upload the CSV/Excel file to a file sharing server, and PM me. I'll walk you through the steps of MAF scaling using VGI's utility.

Alternatively, you can visit Steve99's maf scaling thread where you can figure out how to scale your maf using these tools and the posts from kodename, steve, and other authors.. just a lot of posts to sift through, but wholly encourage it for the learning value :)

Indeed, I checked and retorque my headers for any leak and could not find any.
I am currently running shell / chevron 91 and it doesny seem to change.
I would guess its maf scaling due to a trd intake( still oem right?).

Is the Perrin inlet hose a serious intake mod that would require MAF scaling?

It depends on whether or not it works with your system. What are you seeing in your logs?

I read steve99's link on MAF Scaling and it's recommended not to adjust it while running E85 due to varying ethanol content. I seem to be getting the ethanol on the higher end lately as my LTFT is close to +10% requiring me to toss in at least a gallon of 91 gas to drop it. My IAM has been stuck at 1 the whole time I've been on E85 (about a month now) but I do get the occasional <.75 flkc

Im running E85 and have rescaled my MAF several times for the Grimspeed. I've kept my eye on my fuel trims all the while and haven't noticed anything alarming. My LTFTs look pretty good now usually around +1%.

I'm not running any type of intake mod aside from a perrin inlet hose though. I will be starting to log Intake Temp as mentioned, will see how that turns out. What was the range of your LTFT values prior to rescaling your MAF settings?

Also you maybe getting a more consistent amount of ethanol in your E85. I'm not measuring mine with a test tube and with me adding varying amounts of 91 gas everytime, it's surely going to muck things up. Might be going back to 91 gas after I get my OFH anyways.

If fuel trims are less than 5% everywhere except idle it not rearly an issue.

TRD intakes are pretty close to stock
perrin inlet hose only will not usually effect maf scaling, complete perrin intake will

you sudden knock is likely due bad batch of fuel.

http://www.datazap.me/u/trurace/e85-...og=0&data=2-11

That is one of my logs with a setup similar to yours. It was around +5% at WOT, and usually around +2% cruising. I try to stay pretty consistent with the gas stations I fill up at.

I'm wondering that. I rescaled Iris' maf and tried to fix some of the bad (-2 + FBKC) knock happening at upper rpms, and I guess there is more knock with the new map...

@iris mm is this usual for the IAM to be this low/inconsistent?

That upper rpm knock you see will be due to the maf rescale, on stage2 tunes the ol part of the maf scale is jacked so the tune runs richer than ol fuel table.

Make the ol fuel table say 0.3 or so richer (ie subtract 0.3) for all cells over 5000rpm loads over 1 if you want to keep the rescaled maf values assuming thats where you now getting knock.