If I were you I would just add to what you have. The 225hp isn't shit. Build what you have unless you have major mechanical probs. a '90 talon tsi(same as gsx.) It has a VR4 engine swap, 660cc injectors, 50 trim turbo, 2nd gen MAF, front mount intercooler, and a few other dsm tricks, also stuff I don't talk about. I'ts boosting 1.8BAR. Vented to atmosphere. Runs low 12's on 1/4 mile. So, you can see how fast you can get that 4G63. Granted the VR4 has a different head, and a few differences there, but you just have to spend some time(and $$$$$$).