Ok...this is where i get lost, i am planing to turbo charge a ZC DOHC, i have been researching a lot and yeah, size matters regarding the size that the motor can spin easier and the speed that the turbine will spin and push air in the intake, But, 10psi should be 10psi , no matter what the size of the tubine is, once the waste gate sees 10psi it opens...is a measuring unit and should be the same for any given set up, but yeah i have seen the thread of the size bfr and i'm honestly confused.