Depends on octane and IAT and a lot of other factors.
Best way to find out is start low and increase it until you lose more hp from timing pull than gain from airflow.
In addition OP. it would help if you clarify your setup: fuel type, w/m injection, and motor (stock, forged rods, fully built, etc)
For instance, on 91 octane, no meth, stock motor - the motor won't be the limiting factor for high rpm boost pressure.
