The rb25 has a solenoid as standard. before a certain amount of rpm (~4500rpm) the boost is kept to 5psi and after 4500 rpm it goes to 7psi. if u have a bleed valve installed (and fully closed off) you will bypass the solenoid therefore keeping the boost at 5psi. i also thought the wastegate spring was a 7psi spring but its not. im pretty sure its a 5psi spring, the solenoid bleeds off some air after ~4500rpm to reach 7psi. i thought there was something wrong with my car when it was only running at 5psi then i found out what the story was. if u dont believe me do a search....