I was looking at the HKS gt3037 turbo, and i was wondering which trim level i shuld use for an S4 turbo2? the choices are 48t0.73, 52t0.73, 56t0.61, 56t0.73, and 56t0.87... And could anyone explain what that stuff even means? thanks alot...

 

actuallt there are 15 different trim a/r sizes for 3037and 10 different for 3037S the trim is of the size of compresor wheel and a/r is size of exaust housing. larger trim more air it will flow the bigger the a/r the less response you will have. if you are going to run single i would go with 3037S 56t 1.01 twins i would use 56t 0.73 but i think 3037 is to small for single use