MAF tuning Question

[TTVN]

Hey guys i was just wondering if its worth a thought setting up a BEN table for tuning the maf

current adx has MAF vs WB

wondering if we should have a commanded fuel pid logged along side and a calculated BEN table derived from the two

BEN being Base Efficiency Numerator which i think is calculated as Actual afr / commanded afr

then that could be multiplied into the maf table to correct the afr

no idea if its relevent or worthwhile but it was worth a thought

[Holden202T]

with the 808 i use a custom pid to get wideband afr, actual afr and current VE and it does the calc and spits out what the VE should be ... handy for on dyno etc, you can load to a point and use that figure to offset the ve table till the numbers match, but i don't know if thats directly comparable to a MAF scale or not.

one of the maf gurus might be abl to comment.

[The1]

you can use MAF to tune fueling, but typically just use the injector multiplier table. Think of MAF as your auto fuel scaling and conditions monitor. It can drop 400hz on the MAF freq between winter and summer at WOT on my car, so that auto adjusts your fueling for you. As a hotwire sensor can pickup humidity and density as well.

I have a spreadsheet in the enhanced bin page you can use to tune with, just history log your LTFT BLM% and paste the results into the spreadsheet, then copy in your current injector multiplier table, then copy and paste your new on into your tune.
https://pcmhacking.net/forums/view ... =27&t=2518

[TTVN]

wouldnt the ltft only be right when in closed loop though and would take a decent amount of time to collect a decent sample?

i just thought doing it this way is how u do it with efilive etc u can make quick and easy adjustments without having to drive for an hour and works through the whole afr range

thx for the replys

[TTVN]

THE1

would you consider doing a quick rundown on the technique of tuning the maf based systems as there isnt anything in the beginners guide. Im sure everyone would appreciate it if you could do a quick write up with some screenshots of the process

I know i have been avoiding doing the maf setups but i finally got my shit together and got my gear setup to do it

thx rod

[Jervies]

THE1

would you consider doing a quick rundown on the technique of tuning the maf based systems as there isnt anything in the beginners guide. Im sure everyone would appreciate it if you could do a quick write up with some screenshots of the process

I know i have been avoiding doing the maf setups but i finally got my shit together and got my gear setup to do it

thx rod

I second this, i would also be very appreciate of this as well!

[The1]

If your starting from scratch then turn off LTFT via BLM coolant disable, just set the coolant temp cutin to something higher than the coolant, then it wont auto adjust, all it will do is show the correction amount in the STFT short term fuel trims that it wants to apply, just adjust back to 0 at various loads upto PE or log into a history table and use the same excel spreadsheet. I dont use a dyno but i have a few hills and flats around here, two 5min drives around the block using the STFT method and it's pretty much in sync.

Then for high load areas in PE i just WOT at 50% and adjust PE multiplier tables till it's right then go for 100% runs.

then tune up all the usuals of coarse.

Ill write it on the todo if my jibberish needs explaining better.

[TTVN]

ok that does make sense, iv been avoiding the maf vehicles but its really becoming a necessity to start tinkering with them

thanks for the info its appreciated

[budwizer]

So im at a bit of a loss with tuning maf systems also, particularly vs system, now i understand there are some differences between the vs and vt onwards systems.. But the main thing im having a problem with is tuning the fuel?

I could be missing something blatently obvious!! But help in this area would be appreciated

Thanks, Andrew.

[charlay86]

The main difference between VS/VT was the lack of injector rate multiplier table but we just jammed that bit of the VT code into the VS bins so it is sorted if you use the enhanced bin. The injector rate multipler table is used to make steady state fuelling correction with respect to RPM and cylinder air mass.

I have a spreadsheet in the enhanced bin page you can use to tune with, just history log your LTFT BLM% and paste the results into the spreadsheet, then copy in your current injector multiplier table, then copy and paste your new on into your tune.
https://pcmhacking.net/forums/view ... =27&t=2518