[ScrewDrvr]

Depends on turbo size too. You can put the stockers at 18psi and make 440rwhp, or you can put a sp74 at 18psi and make 625rwhp

 

[ScrewDrvr]

so if you were to take your bpu'd car and minus all the rwhp that you get from all bpu mod's except cranking up boost to say 18psi on 100 octane what would be the result of rwhp from just that?

Different cars make differnt hp. Differnt compression, different exhaust, differnt intakes, condition of the turbos, weather...etc..etc

There is no one answer for this. One guy made over 480rwhp on his stock twins no nitrous, others struggle to get over 420rwhp.