I helped a mate set up a 1GGTE in a 1990 hilux the motor was with stock internals and head , single GT 30/40 Garrett , FMIC , custom plenum , Haltech ECU and extra 6 injectors , I tuned it on the dyno and got 208 RWKW's can't remember the boost but it was pulling 13.1's , So in a lighter car and something with better aerodynamics than a hilux I think you would be looking at low 12's .