Timing vs boost psi

How many degrees of timing per psi of boost do you pull

Well it depends on particular engine, CR, cams, fuel type, boost level... For instance Mitsubishi Evo 4g63 with 1 Bar of boost with stock cams on 93 Octane pump gas is pulling 1 degree per psi of boost. Intake manifold air temperature is also effecting this number big time...

There is no set formula for how many degrees to take out. Changes on every application

In an idea world you are tuning to MBT or wherever your knock limit, minus 2-3 degrees for some safety.

If you are venturing into high boost areas and unsure what timing to start with, then just start conservative (low timing) and work your way upwards to MBT or Knock limit.

You may find that some engines require almost no timing during peak torque, and others will want it to make power. Only experience will guide you through this, so just play it safe till you have an understanding of what the engine wants.