Cadmoon, what mods do you have?
The RB20det in my Silvia has 210hp at the wheels with stock turbo and injectors, only mod is a intercooler and exhaust.
Also it has leaking intercooler piping which is not helping the fact.
The RB20 is generally underrated , in a light car like an S13 it will leave most SR20s for dead.
I have since changed the Turbo to a GT2860rs I have a Niztune ECU, 660 cc injectors and a Z32 AFM ready to go in, should make around the 300HP atw, not too bad for a car weighing under 1.3 tonne.