I would not lean it out if I were you or you will be building A new engine.

 

I run 9psi 11.8 at WOT
No KR
I would not go leaner than 12.0:1 on my truck. 11.8:1 is really pushing it in my opinion. Only running 18* of timing as well. Bumped it up to 19* once and lost power.

 

again, a perfect example of everybody is different. I ran 19* forever at 11.7:1. Just recently put it to 21*. using the IAT advance to back it down. It makes a lot more power on the butt dyno.

 

On the old school motors I ran 12.5 to 12.8 A/F at WOT, never hurt anything. On my modern builds (Lightning, twin turbo GTO) I ran about 11.8:1 A/F. On pump gas the extra richness gives a bit more safety factor. I also picked up 60 rwhp on a Procharged big block by richening from 12.7 to 11.7, most likely due to the extreme heat of the dyno day (105+ degrees in the shop).

Like others have said the richer A/F doesn't cost much power and gives more cushion against detonation.

Jody

 

well guys then it looks like the tune isn't too bad after all. Thanks for the help

 

yup, 11.5:1 here as well at 6-7psi on a stock motor anytime i'm in boost, the rest of the time its around 14.7 to 14.9 afr.