Optimum air/fuel ratio

[REGALTURBO]

This may have been previously asked many times in the past. Question for the tuning guru`s. I just purchased PLX devices wideband O2 tuning tool. Looking to get every little bit out of my combination. What is the target air/fuel ratio I should be shooting for?

 

[azgn]

most folks use 11.5 at wot and big boost

 

[bruce]

In a half dozen 10 sec cars, I've seen anything from 9.5 to 11.5.