Ive never seen a 9 sec gtst before tho
But your right, u of course have to figure out what u want from it, and b0neR has already done that and has asked the question.
Ive got a rehashed T3/T4 with the original R33 exhaust housing hiflowed and a .60 T4 Comp cover over a GT25 comp wheel... I got full boost by 3000 at mo but my exhaust wheel trim needs to be changed because its making the compressor wheel surge a bit because of the quick boost.
3500 full spool is the plan with the new wheel and 250rwkw at 1 bar ..
It hasnt made that much power yet but hopefully the macka special will come together...Its making the times so thats all that matters to me