Question on LTFT affect on AFR PE
Thread Starter
Teching In
Joined: Jul 2002
Posts: 8
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From: Cincinnati, Ohio
Question on LTFT affect on AFR PE Is there really a reason to try to zero out the LTFT's? I understand that they are additive to the WOT PE, but it seems to me if the LTFT's are stable as they usually are (as long as your mods don't change), then changing the PE with LS1Edit is all you would need to do -- or is there some sort of feedback between WOT PE and LTFT's that would cause the LTFT's to change.
Also, I'm wondering what the significance is of the AFR that I monitor with LS1LiveV5? It seems to vary from 14.6 at part throttle to 11.4 to 11.7 at WOT -- does this bear any relationship to the actual AFR (if so then it's awfully lean at WOT), yet my O2's stay around 885 to 900 millivolts.
And finally, I zeroed out my LTFT's by upping the MAF by 12% with LS1Edit, but now I seem to have some significant knock retard at high rpms --- isn't zeroing out the LTFT's supposed to raise the overall enrichment everywhere (causing the trims to drop) so that the WOT AFR should remain the same?
Something just doesn't seem to add up with this. I'm considering going back to baseline again and starting over with a fresh LS1LiveV5 Log. Or should I just start pumping up the PE in 5% increments until the KR goes away?
Unfortunately I don't have access to a Dyno or wideband O2.
Dennis
Also, I'm wondering what the significance is of the AFR that I monitor with LS1LiveV5? It seems to vary from 14.6 at part throttle to 11.4 to 11.7 at WOT -- does this bear any relationship to the actual AFR (if so then it's awfully lean at WOT), yet my O2's stay around 885 to 900 millivolts.
And finally, I zeroed out my LTFT's by upping the MAF by 12% with LS1Edit, but now I seem to have some significant knock retard at high rpms --- isn't zeroing out the LTFT's supposed to raise the overall enrichment everywhere (causing the trims to drop) so that the WOT AFR should remain the same?
Something just doesn't seem to add up with this. I'm considering going back to baseline again and starting over with a fresh LS1LiveV5 Log. Or should I just start pumping up the PE in 5% increments until the KR goes away?
Unfortunately I don't have access to a Dyno or wideband O2.
Dennis
Staging Lane
Joined: Jul 2002
Posts: 82
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From: Houston
Re: Question on LTFT affect on AFR PE 11.4 to 11.7 is rich. 11.7/1 is less air than 14.7/1 or stoichiometric. The 02 volts only tell how much oxygen or lack there of is coming out of the exhaust, not how much is going in. And high 02 voltage (.900mv) indicates a rich mixture as well. Anywhere in the 11s is too rich for a N/A engine. I do not know how to use LS1 Edit, but if these AF ratios are correct you need to do something different.
