I don't think wrx are that light either.And why are you only running 15psi? You have a fuel pump and fmic should easily be able to run near 20psi with decent fuel.You should have enough injectors for that.An extra 5 psi should do quite a bit.

Course he can up his boost too and start modding.Makes for some good competition.And also isn't the wrx a 2.4 and if so will have more torque and more area under the curve also making it faster.Just bolt on a 50 trim already!