Thread: I am so lost on MAF tuning for AFR

I'm trying to figure out how to tune my AFRs by tuning the MAF with % error through HPT. I know that I'm supposed to copy/paste the MAF % error from the scanner into the MAF table in the editor using paste special. I was going by the Russ K method then found that the MAF error histogram (#8) wasn't reading. Now doing some more looking around it looks like some people say don't use the Russ K method and just go straight off of the % error which is a custom histogram. What am I supposed to do, to many opinions and writeups for me to figure out what is going on. Apparently this is supposed to be simple and quick but not for me I suppose.

It will be quick and easy once you figure it out. Set up a histogram to record ltft's against MAF Hz. Multiply these numbers against the MAF table for values under 6500 Hz. The ltft's should be logged for more than one quick wot burst. Do a lot of cruising while logging and then use the information you gather. For the MAF Hz above 6500, you will need the wideband to get it dialed in. You will need to set it up to log your wideband readings and commanded afr at the same time. The % difference between these two values is your afr error. Do one run slowly rolling into the throttle up to wot. This will give you a rough idea how far off the 6500+ Hz range is. Make an adjustment and then do several runs to fine tune it. More data will give you better results than single runs. Do not adjust single points if you only have single point data. You need to feather in the areas around it. For example, don't make a 10% change in one MAF Hz value and nothing to values next to it. If you have no data in certain MAF values, look at the data you have nearby and smooth it out.

Apparently I'm doing something wrong with setting up this histogram. How exactly am I supposed to put in it? Every time I think that I have something right it doesn't read.

For something to log in HPTuners it has to be in the table first. I made the same mistake when I first started with it. I couldn't get certain numbers when I added them to the graphs. Go to the table display and add what you want there and then it will log it for you.

I already figured that out with the WB lol

As it sits now I have the histogram up with the plot value set as the LTFTs in % and for the x-header table it is maf airflow vs output frequency. Is this correct?

If you want to shoot me your e-mail, I'll send you the two histograms I use for ltft and afr error%. You can import them from there. You'll have to change the PID for the wideband though since I'm logging mine through the A/C.

NM. Just realized I still have it in my sent folder from Gary's tuning guide. I'll send you the two histograms I use.

You've got mail. Let me know if it works for you.

Just sent more info in addition to that to help you set it up.