I have a 2003 WRX Sedan. I have an Injen race Division Intake, HKS SSQV, and HKS Catback. How much horsepower can I expect, and also what would my quarter mile time look like? any ideas would be helpful?
You havn't done much yet. You'll be luck to break into the high 13's. Most likely 14.0-14.3.
Note: Most people out at the 1/4 mile stripe are only getting 14.6-14.9 secs.
My recommend taking off and selling your intake and SSQV. Unless you just like the Bling, Bling. Then with that money buy something that adds real horsepower like an upipe and downpipe (which is good for another 15-20whp).