MAFT Users please enter

[RMeadows]

Was tuning the car this morning and I was curious about something. The tuning instructions within the booklet say

Make a test drive and log the fuel and O2 trims

Adjust the BASE knob to keep the total trim between 80% and 100% during steady state driving (35-45 mph). To lean out the fuel curve, set the AUX/BASE to a larger injector size. To richen the fuel curve, set the AUX/BASE to a smaller injector size.

You will need to readjust idle if you make changes to the base setting

Perform some light accelerations in 4th gear starting at about 2000 RPM and watch what the total trim does as the airflow value climbs. Adjust the MID control if the total trim value at moderate flows (300-400hz, high trim) is significantly different than the low flow (100-150hz mid trim) total trim.


My question is, is this part really necessary? Does the F2O2 NEED to be between 80-100? The car runs fine when it's not setup that way, and i've noticed that if I do need to do it this way I have to make some rather significant adjustments, which doesn't seem right considering I have a Keydiver chip. Can I just skip this part, tune for no knock and then adjust the knobs if necessary after keeping an eye on my fuel trims?

How are you MAFT users going about making adjustments? Just as the booklet says or something else?

 

[c4uldr0n]

I didn't use those instructions and am very happy with how I have it tuned. My wideband o2 + datalogger did help a lot for tuning purposes in conjunction with MAF-T though.

 

[RMeadows]

I didn't use those instructions and am very happy with how I have it tuned. My wideband o2 + datalogger did help a lot for tuning purposes in conjunction with MAF-T though.

If only I had a wideband

Maybe that'll be my next mod...

 

[c4uldr0n]

Yeah, after having a wideband, I don't know what I would do without one. There are other methods, which is why they wrote that tutorial up.

 

[xveganxcowboyx]

I've just been tuning for no knock, but just recently changed things a bit and have to retune. Not sure what works best at this point, but leaning it until I see knock and then richening it up a bit seems to work for me.

 

[Quasimondo]

Was tuning the car this morning and I was curious about something. The tuning instructions within the booklet say

Make a test drive and log the fuel and O2 trims

Adjust the BASE knob to keep the total trim between 80% and 100% during steady state driving (35-45 mph). To lean out the fuel curve, set the AUX/BASE to a larger injector size. To richen the fuel curve, set the AUX/BASE to a smaller injector size.

You will need to readjust idle if you make changes to the base setting

Perform some light accelerations in 4th gear starting at about 2000 RPM and watch what the total trim does as the airflow value climbs. Adjust the MID control if the total trim value at moderate flows (300-400hz, high trim) is significantly different than the low flow (100-150hz mid trim) total trim.


My question is, is this part really necessary? Does the F2O2 NEED to be between 80-100? The car runs fine when it's not setup that way, and i've noticed that if I do need to do it this way I have to make some rather significant adjustments, which doesn't seem right considering I have a Keydiver chip. Can I just skip this part, tune for no knock and then hatadjust the knobs if necessary after keeping an eye on my fuel trims?

How are you MAFT users going about making adjustments? Just as the booklet says or something else?

What are the low, med, and high trims? The reason the instructions suggest keeping the ft02 between 80 and 100% is to keep those trims from adjusting, assuming that the ecu was reset from the start and everything was at 100%. If you're running fine just keep an eye on those other trims so they don't get maxed out in either direction.

 

[DROOPY209]

the ECU can only compensate the fuel trims so much before they are out of the ECU's control. Try to keep your trims as close to 100%, and then tune for no knock.

Also, if you have your MAFT in blow thru, make sure that you plug the PCV nipple on the IM. Keeping your valve cover breather hose vented to atmosphere will still allow unmetered air to get into your engine through your PCV valve while your engine is not under boost, in vaccuum, which will in turn jack up your fuel trims and O2 readings.

 

[RMeadows]

What are the low, med, and high trims? The reason the instructions suggest keeping the ft02 between 80 and 100% is to keep those trims from adjusting, assuming that the ecu was reset from the start and everything was at 100%. If you're running fine just keep an eye on those other trims so they don't get maxed out in either direction.

Put about 50 miles on it tonight and the trims are 90%/100%/86%

I'm going to try having the MAFT zeroed out tomorrow and see what difference it makes. I'm under the impression that the less I adjust the airflow via the MAFT and the more I let the ECU do it, the better. We'll see how it goes.


Thanks for the info about the PCV DROOPY, was not aware of that

 

[RMeadows]

Found this post. VERY helpful in case anyone else needed help with this issue.

http://www.fullthrottletech.com/showthread.php?t=105

 

[Quasimondo]

I was looking for that link. I used to have it before my computer went tits up on me.