Hi i have a version 6 sti which has been tuned to 17 psi on a stock vf28 turbo with a autronics ecu tuned to 241hp at the wheels with a 3 inch stainless exhaust with a front mount, i am thinking of upgrading to a vf34 if i do will i need to retune my car again? seeing as the vf28 and vf34 are very similar?