Unless you have a forged motor and built tranny I highly doubt your past the 300 HP mark. 300 Hp in these cars requires a ton of mods and not just bolts on running high boost. It requires a specific tune, most likely a full stand alone EMS. The guys making 300 HP+ know they are making 300hp+ cause they've invested countless hours tuning, and building the block and tranny ect. To be honest You most likely in the 220-230 range. You have a nice set-up, and some solid mods. I would love to see a dyno though.