sell you car, spend the 4k on cocain and buy a ripped vl turbo...........
On the other hand 4k will proberly get you,
ECU ($1000),Pump($200),Injectors($500),Turbo($1000),Tu ne($1000) and maybe an STi TMIC($600) going over budget a little.
This MIGHT net you 12's. However expanding the budget a little more might get you a clutch after the first few runs of 6k sidestepping to get the 12's, and a new gearbox after flat changing 1st-2nd-3rd-4th.