Fixed MAF

[aaronson]

Just wanted to make a post to thank all those that answered my questions about my fueling issue after installing a JLT. Come to find out I had a sizable exhaust leak that Was causing the car to go lean. I just couldn?t hear it because of normal exhaust noise. Once I got that patched up I put my MAF values back to stock. Both flow rate and period. Then used percent difference to find a constant to multiply my MAF curve by as a base. Let the car idle in park for 5 minutes logging long terms, then handbrake on in drive(to load the motor at idle) for 5 minutes. Stopped the log control C, the recorded histogram the paste special, multiply by percentage. Loaded tune. Logged Long terms again. The values where not more than +\- .8 then drove the car for 20 minutes at varying rpm and load, rinse washed repeat, now my long terms average less than 1% correction and my short terms average between 2-5% correction average. Thanks murfie, veefour, decipha, crank automotive and who ever else made suggestions. Such a stupid oversight to not check for exhaust leaks.

[Cranked Automotive]

Thanks for making this thread, i only joined this forum and started tuning about 6 months ago, I appreciate the hrs of work and time the other tuners put into helping out and hope we can grow this forum together.

[aaronson]

Thanks for making this thread, i only joined this forum and started tuning about 6 months ago, I appreciate the hrs of work and time the other tuners put into helping out and hope we can grow this forum together.

So here?s actually something I found when doing the calibration(as this is my first time using the coyote cookbook method of dialing it in). When you?re doing the fine tuning after dividing the new MAF area by your stock MAF area to get your multiplier constant( which is what I usually do). The coyote cook book says to drive the car under various load and engine speed conditions to fill in the long term histogram. Then you use the average of the long terms(at least that?s what they say). I found an issue with that process. So what I would do is look at the average and look at the last value defined as L at the top of the histogram. What I found was that when you initially retune your car it causes the averages to be very screwed lean or rich. So after driving around for 20 minutes, varying load and engine speed, I noticed the L values in the histogram would be consistently between 0 and +/- .8 for long terms. So the averages would be unrepresentative of what the car is actually doing. Knowing this, I only changed the MAF lb/min in the area where the average and the last values still on average correlated with each other. Before I figured that out I noticed I was sort of chasing my tail. Long terms average would say lean so I?d multiply by the percentage, then the average would be rich . So I?d multiply by half average. Then it would swing back the other way. Essentially I looked at the L value of the histogram and left everything alone that was good and changed what was rich or lean

[tbrtuning]

Use STFT + LTFT instead of LTFT only

[aaronson]

Use STFT + LTFT instead of LTFT only

Ahh yes that too 😅 so much to do in the name of dialing in air/fuel

[Cranked Automotive]

I have never read the cook book myself, mostly self taught by watching YouTube videos, other than speaking to one of my technician friends who is a well known local tuner. I used the same methods to dial in the maf on my 2016 GT as i used on an z06 ls7, after many revisions i found that the cai manufacturer provided maf transfer row values that also needed adjustment. I than played with the maf period row to better suite my cars frequently visited period points. After all this i got my maf curve looking smooth and the OL fueling with cyl air anticipation disabled within 1% across the entire load/rpm all the way to 7500rpm. After this i turned on the cylair anticipation which threw my fueling off, near the top if was off by 4-5% rich and mid rpms 10% lean, after playing with the SD tables iam now within 1% of wot fueling over 4500rpm and am working on dialing in my low/mid rpm SD fueling. Its a long journey, but the cars a beast now.

[paulsmithsr]

Log data - and correct fuel trims easy done

[aaronson]

I have never read the cook book myself, mostly self taught by watching YouTube videos, other than speaking to one of my technician friends who is a well known local tuner. I used the same methods to dial in the maf on my 2016 GT as i used on an z06 ls7, after many revisions i found that the cai manufacturer provided maf transfer row values that also needed adjustment. I than played with the maf period row to better suite my cars frequently visited period points. After all this i got my maf curve looking smooth and the OL fueling with cyl air anticipation disabled within 1% across the entire load/rpm all the way to 7500rpm. After this i turned on the cylair anticipation which threw my fueling off, near the top if was off by 4-5% rich and mid rpms 10% lean, after playing with the SD tables iam now within 1% of wot fueling over 4500rpm and am working on dialing in my low/mid rpm SD fueling. Its a long journey, but the cars a beast now.

The first year 6-12 months of tuning was really just a lot of trail and error, I read a lot of what to do on here and what not to do, watched as many videos as I could find on how to navigate the editor. I used the sample copperhead tune that comes with the software to familiarize myself with a lot of the tables. And I would tune anybody?s car who would let me for basically free because I wanted the data and knowledge from doing it. I bought the coyote cook book and used some of the things out of it, but never really went through and did a whole entire tune based on the book, that?s basically what I?ve been doing with my car now to get use to a more proper way of doing things. Especially adjusting torque tables for boost. But as it says in the cookbook since the text has been written a lot of the processes have been improved and changed, so I figured what better way then to share my finding so someone that buys a JLT without data can also dial in their car. Decipha has values on his website that work really well to. I just wanted to see how close to 0% fuel correction I could get because I?m anal about it.

[aaronson]

Log data - and correct fuel trims easy done

Exactly, simple concept, long process