I have a 1jz Supra on a single, with a Turbonetics wastegate. The car has not boost controller and boost levels go to 18 psi (half throttle)then fuel cut kicks in. My question is; how do I lower the boost? do I have to get a low PSI spring from turbonetics ? In the picture of the Wastegate you can see where the vaccum hose is connected to the wastegate, but right under it theres another fitting, whats that for?