[8695Beaters]

Turbo, exhaust manifold, intercooler, injectors, fuel pump, turbo piping, boost controller, BOV, and a good tune are the most important items. Other things that will help will be a 2.5" exhaust, intake manifold, new head gasket and an lsd. You might even be able to squeeze out 9 psi or even 10 if your tuner is really good. The turbo you can outsource from a junkyard. Just try to find a 1.8-2.4 liter engine with a turbo on it, preferrably with low miles and is in good working condition. The most important thing is to make sure you have enough fuel to supply your turbo or you'll go up in smoke. 9 psi is pretty safe on the stock internals, 10 psi is on the limit. Any more and your motor is toast. Just remember, you're also going to have to suck up the cost of premium fuel and make sure your insurance company is cool with you going that insane with your car. Many insurance companies won't touch modified cars or cars that ever see the track.