Just got a 03 wrx and I want to purchase a esxhaust system and an intake, you guys have and suggestions, price dosen't really matter I want some quality stuff. Thanks

 

Firstly, id like to say that 90% of all CAI (cold air injection) kits prove more problematic then beneficial (search if you dont believe me but please do) the ones that seem to work are the perrin and avo "shorty" ram intakes.... the stock air intake is about as good as it gets until you goto a Front mount intercooler (it interfers with the stock intake so you have to change it) or are pushing HUGE hp numbers


regarding the exhaust... there are a couple different routes, but a trend in theory....

1. get rid of the "up-pipe" it has a cat and it connects the manifold to the turbo... it is possible with extra heat cause by extra boost to "melt" the cat stuff and then send a bunc of litle pieces through the turbo and bye-bye turbo...you also get about 500rpm quicker spool up as well...definitly noticable on the butt dyno...also....get new gaskets and follow the instructions (lots of uppipe likes --- think screech of death are a result of those 2 things)

2. Downpipe.... pipe that connects the back of the turbo to the exhaust...the stock one has a flat-plate covering the wastegate and is 2.25" diameter while there is much debate as to whether an "open bellmouth" (one big pipe that "swallows" the whole back of the turbo) or a "diverted bellmouth" (seperate pipes for the wastegate and turbine blades) is better I personally have a Perrin diverted downpipe with a high flow cat and could not be happier

3. the rest of the exhaust - there is a "mid-pipe" that has a resonator and then the backbox all 2.25" piping...the general consensus is that replacing the midpipe is beneficial but the stock muffler doesnt start being restrictive till about 300whp


You also have a couple ways of approaching the setup...turboxs makes a "stealth-back" which is downpipe and midpipe it connects to the stock muffler.... it has an "bellmouth" downpipe...lots of happy customers it seems.... Vishnu performance sells a similar setup with a 5zigne(?) exhause....lots of happy customers as well... however, IMHO its cheaper to piece togther a system that even though its not a true "system" it still functions just as well

my setup is as follows:

Godspeed up-pipe (it leaks with new gaskets but seals after 10min of running no big deal)

Perrin downpipe with Cat - love it no check engine lights (duh) and no boost creep

and finally I went to midas and for $200 i had a 3" crush-bent pipe made with flanges so I could remove it from my downpipe all the back...just a warning it is SERIOSULY loud... I mean like v8 open headers loud....too loud needs a muffler....

one more thing-
before the straight pipe exhaust I put my car on the 4wd i have @ work and netted an impressive 220whp and 230ft/lbs of torque with a slipping clutch!!! ( i know theses are peak numbers but still impressive for stock ecu and stock turbo) I had up-pipe, downpipe, i/c hoses, and i had a 3/16" vacuum inline with the factory boost controller netting me abotu 16.5psi in 4th gear =)

hth
~wrx300

 

Right on, I work in Hinsdale right off of Ogden.

 

What are I/C lines and a 3/16 vacuum line? Is that something easy to do and what exactly does it do.

 

I work at Continental Autosports, right by 294. I live in Bloomingdale so I don't hang around in this area much.

 

wrx3001 thanks for the very informative reply. Have you heard much or do you know anybody that has installed any prodrive stuff on their cars? So have you just installed a aftermarket air filter in the stock housing or did you do anything?