so i was wondering if i need to retune my car if i turn up the boost on it. right now its pulliing 300 whp and on 8 lb. if i turn it up or turn it down, will that mess up the tune? i am tuned on s300 and 3 bar map sensor and 1000 cc injectors. thanks.

 

turning it down is fine. turning it up requires a retune.

 

What's your a/f at 8psi and what is done to your motor? Some shops give you a little extra fuel after the tuned psi and some don't. If you have a wideband and if the motor is built enough, I would try going up by 1psi at a time.