How to correct WOT AFR in each gear?
#1
How to correct WOT AFR in each gear?
I am having an issue regulating the AFR in each gear. I usually tune in third from 2,500 to 6,700. But what I notice is when I get a good 13.00 AFR in that gear 1st and 2nd are lean and 4th is rich. 1st will be off by as much as half a point where 2nd will be 2 to 3 tenths off. Now 4th will be rich by 2-4 tenths. I figured it may be a MAP KPA issue but it isn't that. So I looked at my MAF freq. Nothing there. The car basicly runs in the same place in both tables in all gears at WOT. What am I missing? Why doesn't the car run the same AFR at WOT in all gears? I am running EFI Live. Is there a table I am missing that will compensate for air speed?
#3
I tune in OLSD first with the commanded AFR of 12.93 and PE modifier of 14.63 like described by EFI live. Then I re-enable the MAF and tune that with the PExRPM at 13.00. It would probably be easier for me to email you my file. It is on my lap top and I have to get it to a thumb drive then onto my PC then to you. If there is an easier way let me know.
#5
Formerly 4mulaJoe
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I just wanted to bump this to the top. I see the exact same thing when I am tuning. It's not a MAF issue as I am doing it in SD mode. The higher the gear, the richer it gets. PE enable is set to 0. Commanded AFR is the same across the RPM range.
It doesn't present too much of a problem really, but I can't figure out why it does this.
It doesn't present too much of a problem really, but I can't figure out why it does this.
#7
Kleeborp the Moderator™
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I see the same thing tuning open loop SD...I just tune 4th gear only since it tends to be the richest. IMO, there is nothing you can do about it, so just tune the highest gear you care about all the way out, and let the others be a little lean. You aren't in 1st or 2nd long enough to matter, and those gears aren't putting as much of a load on the engine anyways.
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#9
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yea but what sux on the dyno is it doesnt have all that air going in your motor if you have a vararam and are doing 130-140mph worth or air being shoved in your front screens of your vette...so is it safe to say itll run a lil leaner on the street? Glad i have a wideband....Pray PMed you on CF...EFILIVE tuning my HCI Z06 here in goldsboro not too far from you
#11
I believe that the issue is in the acceleration difference from gear to gear. The acceleration from 2,500 to 6,700 or from any RPM to 6,700 is different from gear to gear. It's fastest in first & slowest in 4th. You'd need an injector pulse width per gear or per acceleration rate table or something similar to dial it in completely.