What kind of afr's are you running with the gm stage 2 tune and a 2.9" pulley and are they safe?

 

veryyy richhh like 10

 

if you have the gm tune you are gonna run very rich regardless of what pulley you have. The gm tune doesnt change. It demands a 9 or a 10 afr. I have a 2.9 pulley on the gm tune and work like a chram

 

What kind of hp gains would you see from a custom tune over gm stage 2 tune?

 

I would also like to know this. I would guess leaning it out would probably increase 10-15 whp.

 

anyone?

 

factory 2007 gm stage tune commands 11.3 right around 4000rpm, and richens up to 10.8 from 5000rpm and above. in my experience with the 2.9 on 42's, i started running out of fuel at 7200rpm, leaned out to 12.3 at that point when it was holding ~10.9-11.0AFR. dont spin it too high and you will be fine

 

i actually just ordered a 2.85...not 2.9 but close. i'll datalog it and post what AFRs im getting. Probably going to go to 60#s pretty soon but i'm interested in seeing IDCs and AFRs with this pulley.