Need help with MAF upgrade

[CHIEFAPONTE]

I recently upgraded my injectors to HKS 600 cc injectors and a set of z32 MAFs.

My car is a 1991 R32 GTR. with the following mods

R34 N1 turboes
pomcams 260 cams
catless 3 inch exhaust
NISTUNE FP ECU

on the injector install, I followed the menu on the nistune software to include the adjustment on the cranking tables, max load limit and TIM. After the injector resize the car ran well. minor adjustments to TIM got the AFRs very close to the target.

The problem I have is with the MAF resize. Once the Z32 MAFs are installed and I go through the change MAF utility on NISTUNE, the car would not start. I then changed the values on the "MAF VOLTAGE QUANTIFIER [RAW]" to reflect the same values of the stock R32 MAFs and the car ran fairly well but rich.

I then adjusted Kconstant down and TIM up(see attached BIN) and the car misses just a bit on initial acceleration, but I am concerned that my adjustments of K and TIM may be too much.

Can anyone look at the attached file and give me some advise?
what do you think about me having to replace the MAF VOLTAGE QUANTIFIER [RAW] values for the original values?

[CHIEFAPONTE]

Update. I decided to use the vq transfer generator and using the data for the hpx n1 maf and scaled to 33% i got the car running and accelerating well. The only issue is that the AFRs are a bit rich.

[Matt]

Make sure the 'R32 GTR' MAF tickbox is selected when doing the MAF resize (adjusts the K constant differently)


The K constant needs to be adjusted with twin MAFs when doing this resize. What you can do is resize again to the Z32 MAFs and then adjust the K constant afterwards until car starts and runs again

If you have feature pack, adjust K constant until load reaches the end of the fuel map (adjust the Total Injection multiplier) to adjust your fueling to be back to normal

[CHIEFAPONTE]

Thanks Matt. I do have a FP board.

what does it mean when you say "adjust until it reaches the end of the fuel map"?

Should I adjust only TIM? Or K constant only? should I tick the "auto TIM" as I adjust Kcont?

how much of a split on my MAFs is too much? my logs show an average of .2 to .5 volts

please explain and thanks a gain for your patience and help

[CHIEFAPONTE]

Matt. my MAF resize issue has been resolved. I believe the issue with my maf resize was that the option named "Z32 VG30DETT (GTR ECU)" was bad. I re-did the procress using the option named "Z32 VG30DETT" which worked fine.

attached is my bin file.

Thanks for the help

[Matt]

That item is only so that after doing resize it will show as Z32 VG30DETT (GTR) ... perhaps I should remove it since it is causing confusion. Instead it will show as 'unknown' however