ok here is the question.i am building a new turbo motor,here is the set up-b18c block with darton sleves and erl super deck 1,crower 4340 rods,je pistons,pro drive oil pump,ferrea valves-springs-retainers,stock integra type r cams and crank,sfp mani,sfp 2.5 down pipe, tial wastegate and blowoff valve,pression sc61 turbo,aem ems with gm boost silonoid.what i want to know is what spring i need for the wastegate if i intend on running 400 to 420 hp???

 

figure out what the minimum psi that you want to run is. if you ever want to turn down the boost, the lowest setting you could go would be that of the spring.

so say someone wants to run 10psi, but they may want to drop it down to 7psi or so for just normal driving. in this case, you would want a 7psi spring. with a boost controller you can always turn up the boost, but you cant turn the boost below the spring setting of the wastegate. just keep that in mind when choosing a spring