yes mate had 15psi in tryes ,im thinking if you use hand brake will it help 60 foot time and I have 12pound spring in my external waste gate putting smaller spring will bring boost on earlier not sure if it will drop high end of boost which is 19psi,also thinking of getting bigger stall convert 3000rpm might help any one using to4z turbo what stall conv should run with this turbo which I have noticed boost comes on later than standerd turbo and boost is longer range with this turbo any help guys ,chasing goood 1/4 mile times .