write am runing strd turbo with power fc,720 injectors,z32 maf etc am thinking of getting gt3071 with 4branch internal wastegate,if i go ahead & fit this would the maping on the car be miles out or would i need to go straight onto the rollers for a new set up car at moment is runing 336bhp 1.2bar,what figures would i get if runing 1.3bar with the new turbo:-D