last year i did some work to my car. The end result was 347RWHP & 354 RWTQ After the dyno tune I took my dyno sheet and filed it with some other car stuff. Then today I was reading the Sept 96 issue of high-Tech performance. Got to page 30 and found an article on A/F ratio. Stating that Max H/P is usually at 13.1:1. So I dug out my Dyno sheet and found out they decided to dyno my motor at 12.1:1 A/F. So my Q is how much if any H/P I'm I giving up. And is it possible that for some reason my motor Just seemed to like 12.1:1.............joe

 

You could pull some more power out of it, but I dont know how much unless you do it. I think the LT1 is 13.5 and the LS1 12.5, but I dont remember.

 

I'd say you're leaving some power on the table, how much I don't know, but if you're only running at a 12.1 then there's room for improvement on the tune.

 

Can anyone else help............

 

Damn, that's pretty rich, especially for NA. Every car is different, some like richer AFR's then others.... that's one of the reasons you tune on a dyno

Typically an engine will make best power within a small range, and you tune towards the richer side to keep it safe without sacrificing much power. Usually the richest AFR is best at peak torque and you can lean it out slightly after that. A good tuner should know what he's doing. Also keep in mind that the car will usually run leaner on the street then it will on the dyno since the car weighs more then the rollers, but this isn't that significant.