I recently sold my 1993 ford mustang. I have always liked WRXs and i recently purchased my first one. My old stang have 400hp at the crank. Im looking to get appx 300whp out of my 2003 WRX 2.0L. Any1 have any insight on how to get there. My current plans are wheels/tires, BOV, and exhaust.
Start with a Bellmouth DP, and then look into engine management (Either Cobb AP, or the Tatrix Cable and software). That all can be had for cheap if you dont mind looking around for used stuff. To get to 300whp, can be done by using all used STI parts (TMIC, turbo, also look into a 3 port boost control solenoid, maybe an inake), and a decent tune.