aaron_ions

hi guys, ive got a 2004 wrx uk and am just looking to get the best out of the standard setup really with a few bolt on goodies. i had a classic with a td04 and spent alot of money on bigger turbo, all supporting mods and map etc and although it made good power, i missed the responsive td04 so this time looking to get the best of a stock ish setup.

my main concern is the cat.
currently have fitted a 2.5" ninja backbox and straight through center, k and n panel filter and silicone y/boost pipe.

before the map i was going to fit an sti up pipe to decat it, a decat 3rd cat pipe (one straight after d.pipe) but leave the stock downpipe cat in.
also a walbro pump, bit of act pretension and 3port fitted before map.

so my concern is the cat, if i leave the stock cat in the down pipe but the rest de catted will it still be emissions friendly as what i have read the prodrive sports cat is said to pass mot's when nice and warm, will the stock downpipe cat be the same come test time?

also i know the stock d/p cat is more restrictive than a sport cat/de cat pipe but with the other mods mentioned do you still think it will make the average 275hp/290tq ish. from what i have read it probably will.

i know i could go out and get a sport cat, but if unnecessary where mot is concerned and for a couple of bhp extra that i wont notice i wont bother if i can get away with it.

help and comments welcome. thanks all. Aaron.

TECHNOPUG

iTrader: (1)

Pretty much as you say. The cats post turbo are what effects the power, the up-pipe effects spool. Can't say what power you will make as too many variables. You will make less power with the stock cat in place though. But will be more MoT friendly (most sports cats pass though once they are warm).

Personally I'd look to replace it if you can find one at a decent price. Also, there are some ported headers in the for sale section that I'd snap up and fit if I was you.