What AFR?

[gectek]

but if you were looking to be safe, you wouldnt be modding really, i mean that is what it is all about, pushing the limits and asking questions. safe is a realtive term. as long as you have a reliable starting point, you can tune as much as you want, and some engines will take to tuning mods more than others, some come from the factory with KR, mine will pull up to 6300 RPM from the 1-2 shift and never see any KR, and thats with the 1.5 pcm from DHP which is supposed to have more aggressive tables and has to use premium fuel, well i dont run premium and i still dont have problems.

[torq455]

so ya'll are saying that i should just leave the stock afr alone to be safe....

[MMGT1]

Could tell him you want a comanded of 12.9 @ WOT. As Ben has stated you can only do this properly with the aid of a WB. I was commanding 12.8 on the narrow band and with my new wide band found I was only getting down to 13.4-13.6!! So the NB's are completely useless. And no two cars will read their NB's the same!! For example: your car may read, let's say, 910mv @ WOT and mine may read EXACTLY THE SAME, and with a WB yours may be 13.0 and mine would be 13.4......making them, as said, COMPLETELY USELESS!!

[SappySE107]

You can't do it like you want as it doesn'twork that way. Don't guess. If you don't know, set it conservative until you get it on a wideband setup.

[torq455]

yes, but there's what is commanded by the pcm, and what the engine is actually getting, right? i'm trying to find out what i should tell the guy programming my pcm. stock has to be on the rich side. yet i find that 12.9-12.0 is good at WOT. but if that's really 1 point high compared to what the engine is really seeing, then it's really getting 11.9-11.0 afr. so should i tell this guy to go 13.9-13.0?

[sharkey]

generaly you want 12.5-13.2 under WOT on an n/a engine for best power. without a wideband o2 sensor, how does the pcm know what the air/fuel ratio is and how can it compensate for it??? a narrow band o2 sensor just shows anything under 14.7 to be rich, but cant indicate how rich.

[torq455]

Help! 04 GA SE 3400 with a couple of external mods only. reprogramming the pcm and need to know what AFR to command. Supposedly, say during the 1/4 mile it starts at 12.9 and drops to 12.0. From what I hear, the command vs. the actual AFR is different. What should I program this at?