I have a 2004 WR blue wagon, It's stock right now, need to beat my freinds civic si by this summer, his car is way fast. I don't want any cosmetic changes, just performance

 

Bigger turbo!

 

turboback or catback exhaust + reflash.

 

upipe, turboback and reflash is your best bet probably

 

up pipe, turbo back, and a reflash

 

Blow off valve, ram air intake, up pipe, catback, reflash/custom tuned dyno ECU. You will rock his world. Good luck

WRX Rush

 

A bigger turbo (to do it right) will require a lot more money than what you have budgeted. The blowoff valve and intake will do little if anything. Better to get the downpipe. So like the others I say turbo back exhaust, up pipe and reflash.

BTW are you talking 'bout track, autocross or 1/4 mile? Better tires and a rear swaybar will do wonders for the handling.

 

Max power (straight-line goodness) = turboback, uppipe, reflash OR uppipe, downpipe, catback, reflash.
Real world speed = uppipe, reflash, new tires
And why the hell would a Civic Si give you problems anyway? Is he running forced induction?

 

Turboback, uppipe, and Cobb Accesport if you can squeeze that into your budget. A good turboback will run you around 1K, the uppipe around 2 bills, and the port is 600. I know, overbudget, but you can get all for around 1500 if you get a cheaper turboback (maybe greddy evo and hks dp).

 

or buy used up pipe

 

i'm still curious bout your friend's si.

 

wheels and tires
ss brake lines and better pads
silicone y-pipe for the ic
short shifter

 

oops just noticed you said performance only.. in that case, get just the y-pipe, catless uppipe and downpipe

and if you have enough left over, a catback.. but thats something you may want to save up a lil more for.