AFR Question
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From: NW Chicago Subs
AFR Question If I am running at about 14.0:1 and bring it to about 13.0:1 by adding fuel will I gain power? If any change, about how much?
Thanks and sorry for the novice question. I am just getting started tuning.
Thanks and sorry for the novice question. I am just getting started tuning.
Originally Posted by BADSZ28
If I am running at about 14.0:1 and bring it to about 13.0:1 by adding fuel will I gain power? If any change, about how much?
Thanks and sorry for the novice question. I am just getting started tuning.
Thanks and sorry for the novice question. I am just getting started tuning.
Originally Posted by SSpdDmon
Ummm...if you're talking about cruise conditions, 14.7 is optimal. If you're talking about higher load conditions and WOT, you shouldn't be commanding much above 13.0. The leaner you run it, the stronger it will feel. BUT, it will significantly increase the potential for damage to your motor. The extra fuel added going from 14.7 (cruise) to 13.0 (WOT) helps keep the cylinder temps down and prevents the BOOOM you don't want to hear.
I agree with that one...I'm running a 13.5 to a 13.09 commanded...this weekend I will have my wideband set up..if anyone wants to see my tune I have efi live..my car has no internals simply bolt ons in sig and dyno numbers are from a tune before my current one. (I have yet to dyno with my current tune) god i love the ls1 motor.....almost 400TQ and 374HP 
hey man you might have to bring that wideband back here so i can use it lol you will mostly gain power from leaning it up, ive seen 10 rwhp on my friends camaro after leaning it out some, and it was still rich. you want to have as much fuel taken out before you get any knock, or anywhere close to it. but like said you need enough to keep things cool, hotter temps can cause detonation too
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I do not have a wideband yet. I dynoed a couple years ago and it read 14.0:1 WOT accross the board. Since then I have done little. I did some logging and it appears to be inbetween 870 and 920 on my O2s. One pull showed 900-920 and another showed 865-885. I also gave it more timing. I had 0.5 KR starting at about 4200 then dropping off at about 5000 on just about every pull. How am I doing?
You can't really judge your WOT AFR with the stock O2's. The reason they're called narrowbands is because they are only good for a very small range around 14.7, which is your optimal cruising/light-load AFR. When you go WOT, you also go into open loop where the computer ignores the readings from the stock O2's because it knows they're b.s. The only way to get an accurate reading on your WOT AFR is to use a wideband O2 sensor. Chances are, if you have done little since that 14.0 reading you are still running 14.0 at WOT. I highly recommend investing in some tuning software and a WBO2, find a friend who has HPTuners/WBO2, or pay a shop to straighten it out for you. The long-term effects of higher cylinder temps will not be something you'll enjoy later down the road.
Thread Starter
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From: NW Chicago Subs
I have HPT. Just no wideband. I thought you can tune with narrow band, just not as precise. It can't be impossible to tune without a wideband. I will probably add some fuel to my power enrichment table just in case. Good thing I have a thermostat then. I would think I would have more KR if it were too lean, not to mention a light.
