4 psi on a couple hundred bucks? Not going to happen! I'm just starting on a low-pressure turbo kit for my RS, and so far, I've gotten good deals on the two parts I've bought, the turbo and a RRFPR. And I'm already at $300, and I still need a proECM, up/down pipes, external wastegate, intake, charge pipe, and an intercooler. The only cheap pressure you can get is from that e-Ram, the fan thing for the intake, and that only makes maybe 0.5 psi, if your lucky, and probably not even that. And that runs about $300. You want real boost, you're looking at at least $1500 if you can find deals on the parts.