Well as you guys have noticed I have been posting some information regarding my recent MAFT/ATap tuning session, and here is my conclusion. \

I started out at .947 O2's/ -6% LTFT's (pre-MAFT). I commenced adjusting the MAFT based on first getting the LTFT's to a smaller negative number and then getting the O2's to around .900. I won't go into the details, but, I ran 6 different combinations (reset the PCM each time) to get very close to these numbers and . I ended up setting the Base to 0 and only 2% lean on WOT.....not much change but did feel the increased power and pull. I felt good about these numbers and results NA but found it to be little lean during N20 runs. So I then proceeded to adjust the MAFT to neutral (0 base,0 WOT) to start fine tuning the N20 setting. My results NA (no MAFT) after 3 runs are at:

Avg Intake Air Temp: 50.32564297
Avg Coolant Temp: 185.6930057

LFTF B1 -0.958512629 avg for fuel trim cells 1-19
LFTF B2 -1.085406922 avg for fuel trim cells 1-19
B1 & B2 -1.021959775 avg LFTF for fuel trim cells 1-19

O2 B1S1 0.899375 avg WOT B1S1
O2 B2S1 0.9096875 avg WOT B2S1
0.90453125 avg WOT O2's

KR: 0 occurrences (over 3 degrees)

Absolutely perfect....WTF! I started out showing rich before I started this tuning event.......
From this I have figured the PCM needs sufficient time to "even out" with STFT/LTFT adjustments for each individual MAFT adjustment or it means absolutely nada. I was running 0 LTFT's under WOT and now am running slightly higher numbers (1.6 to 3.1%) and my individual separate WOT O's changed from .880 to .920 during the run (ie. slightly rich then lean then optimal). I think the LTFT's are cycling and attempting to adjust the O2's to "optimal". LTFT's should be at 0%. This takes some time obviously. How much..dunno, but depends on a lot of individual variables. I know this was kinda long and sorry for that, but thought I would share this experience and hopefully help others and save you some time and gas money trying to adjust something quickly that does and will take some time and patience. I am going back to "neutral" give it some time to get the LTFT's to 0% @ WOT and start again with the MAFT set at my "assumed" optimal setting, and of course give it time to adjust....and go from there. Once I do I will get my wideband readings to "really" know where I am at. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Hope this helps and good luck!
Randy Hughes
Please post your opinions on this.Thanks.

 

It takes about 100 miles for the computer to adjust.From what I'm realizing you try to get the L-terms to 0% at WOT.When they are consistant you adjust the WOT to the preferred A/F.The WOT A/F will stay the same all the time with a setup like that.
If the computer see's that it needs to + fuel at WOT,then it will affect the WOT setting on the MAFT.
I have my base at 10% rich to keep the L-terms at 0.0% at WOT.I'm going to the Dyno today to tune in WOT.Right now my a/f are reading .93 consistantly at WOT with 0 knock.

 

Slowhawk, thanks for your reply. Let me know how it goes at the dyno. I am going to give it till Tuesday and see really where I am at. The guy at my speed shop said the MAFT is very effective....if you have the O2 wideband to "dial in" the optimum setting. No ****! I can't wait to find out if there is a little more in her...I think their is. BTW, is there a preferred side to put the bung in? Or both?
Good luck at the dyno! <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />
Randy H.