I made 386whp at 20psi on 93oct pump gas with the following setup:
Stock S13 Redtop SR
JWT S1 cams / valvesprings
Greddy intake manifold
Full Race turbo manifold (bottom mount)
3" downpipe/exhaust (no cats)
Enthalpy ECU tune
740cc Injectors
GT2871r .86ar turbine, 52 trim compressor, internal wastegate (t25)
I switched to the .86ar after starting with the .64 and not being satisfied.
I personally think that anyone using the 56 trim, with maybe some 272dur cams and maybe 7500rpms could make 450whp on pump.
Later I cranked the boost to 22psi and made around 420whp, but I don't have that dyno graph unfortunately.