VE Tuning for MAF

[Nitrous]

OK, I finally have the wideband working and logged AFR on the way home from work. I need some advice on how to get the AFR's back in range because I'm running super rich. I've done quite a bit of reading but I'm not sure which table to use for correction. Here's the tune and log if someone could guide me because after reading I'm not sure which histogram to use. AFR error? WB02-AFR? I see AFR error in a lot of posts but the histogram doesn't look right. Any help to get me in the right direction would be appreciated.

[Nitrous]

BTW, MAF is disabled as you can see.

[EC_Tune]

You will use your VE table to make adjustments. Just copy the AFR Err% and right click- paste special multply% on the VE table. Done...

BTW: After this change set your PE commanded to something reasonable again. It's commanding 11.7 AFR right now but you're safe at the moment.

[Nitrous]

EC, I changed the VE table last night by adding and subtracting what was needed and have everything close to 0 when logging LTFT's. I guess I don't see the table that says AFR error %. I logged it but don't see the histogram. I see MAF / AFR error. Please advise, thanks

[EC_Tune]

If in doubt make a histogram...
Just take your VE vs LTFT or STFT and replace LTFT/STFT with AFR Error% and save it as a new histogram. Don't forget to customize the name of the histogram as well.

Here's my AFR Err% histogram. Should be a plug & play result for you.
Drop it in your Histograms folder in the VCMSuite2 directory. Then just replace one of your histos with this one.

[Nitrous]

EC, I actually downloaded that histogram sometime in the past along with others form the downloads. My problem is getting it to open in the scanner. I'll keep reading but how do I add it? Use the configure fistograms button?

[EC_Tune]

Pick a histo to replace then: Click on Import Histograms on the left end of the histogram window.

[Nitrous]

Ah hell, the import button was covered up and I could only see the Export button. I kept reading in the help files and saw that but I couldn't see it! LOL I'm on track now, thanks!

[Nitrous]

everything worked, I just need to write to the PCM, thanks again!

[Nitrous]

EC, things look much better now but I need to change the PE commanded like you said. Where do I do this? All the KR I had is gone also since the VE is more in line. I looged the MAF in Hz and need to make changes there now also.

[Nitrous]

Can anyone tell me if I change the PE EQ Ratio from 3600 - 7200 RPM from 1.25 to 1.00 will that help keep my command AFR from going to 11.7 like EC said?

[5_Liter_Eater]

If you change it to 1.00 it will be commanding 14.7:1. What do you want it to be? For PE, take 14.7 and divide it by what you want your commanded AFR to be and that is your EQ ratio (PE).

[Nitrous]

Excellent, what should I command it to? Right now it's 11.7

[BlackSS]

If you're afr error is correct you can start to lean out the PE.
You want a little on the rich side up to peak torque (12.4 or so), then lean out to max hp (12.8 - 13.0 generally), then fatten it up a little past your peak hp for safety purposes.

[Nitrous]

Thanks, I was wanting another opinion. I'm leaning towards these ratios.

Labels 0 400 800 1200 1600 2000 2400 2800 3200 3600 4000 4400 4800 5200 5600 6000 6400 6800 7200
EQ Ratio 1.176 1.176 1.176 1.179 1.179 1.179 1.179 1.179 1.179 1.179 1.202 1.202 1.202 1.202 1.202 1.202 1.202 1.202 1.202

[1slowsilverado]

make corrections in open loop

[Nitrous]

I was playing around last night and got to thinking about COT causring the 11.7 AFR's @ WOT. Can the COT overtemp have something to do with AFR command going to 11.7 @ WOT without CAT's? False temperatures? I just ordered a set of 3" Random Technology Metal Matrix CAT's to put back on the truck and that was just a thought. I was able to command AFR's to 12.5 by setting the EQ Ration table to 1.076/1.179/1.202 but am I putting a band aid on something. AFR's didn't change to 11.7 until I bored out the MAF to 85 MM and removed the CAT's. BTW, I know temperatures would decrease without CAT's that's why Imentioned false temperatures or possible calculations somehow?

Also, is it better for me to force open loop throught the scanner or through the tune?

[5_Liter_Eater]

Possible. Log the COT satus bit to tell.

But you could tell from your tune that you were commanding ~11.7:1 with the PE alone from 3600 RPM on up.

[Nitrous]

5LE, you're correct, it's that way in the tune so forget that idea. I had to ask though. My stock bin is actually set at 1.288 above 3600. What is yours set at?

[5_Liter_Eater]

1.15 across the board (12.8:1)