What is an ideal air fuel ratio for power without running too lean. on a NA motor? about 13? thank you for any help.

 

13.8:1 is considered ideal. 13.0:1 would be a nice and safe AFR for most purposes.

 

13.8 at WOT? You're kidding right? That is way too lean, even for a naturally aspirated car. If you ran that lean with a power adder, you'll be spending some time learning how to rebuild a short block.

On most NA cars, 12.8:1 at peak torque and 13.0:1 at peak HP is the way to go. If you run power adders, shoot for a safer 12.0 to 12.5:1.