[Shane@DBPerformance]

There isn't a guaranteed safe A/F ratio. Boost and ignition timing will still blow up your motor at a very safe A/F ratio. You need to monitor timing, knock, boost and A/F ratio and figure out what combination of each makes the best power. If you are running moderate boost like 15-18psi with a good FMIC, then might be able to run in the very low 11s or aroudn 11.0:1 on pump gas. If you are trying to push the boost or setup then you might have to run richer and still get knock. A fuel controller like an SAFC or Neo is going to have the side effect(usually unwanted on pump gas) of causing the car to run more and more ignition timing the farther negative you are in the airflow settings.