wrighty988

has anyone de-catted their prodrive exhaust?

what kinda noise do you get and also what de cat should i go for seeming as there is so many its a 2004 impreza sti type uk thanks

wrighty988

ive read sumwhere that the impreza sti exhaust system has a rear cat . a downpipe cat and a pre cat.
what one should i change is the question lol

dnc

No pre-cat, just one in the down pipe and then one in mid pipe for std UK STi. If you have the STi PPP then you just have one cat, a sports cat in the down pipe.

a16pse

im having mine took out on tuesday on m 2006 sti so ill let you know mate.

wrighty988

thanks mate

does anyone know if there is much performance differant between the prodrive sports cat and a decat

a16pse

Be about 20 ish bhp and about 40lbs torque but the main thing the turbo will spool up a lot quicker and a lot more responsive, you will defiatly notice the difference, so yes it is worth it mate.

wrighty988

where would be the best place to get one? does any of the traders on here have a discounted rate goin on or anything?

dnc

You sure about that? I have significantly better figures from mine (prodrive sports cat) than some total decats I've seen on here. I think if you were to ask a specialist they would say maybe 5 bhp difference, not bad on say 350 bhp or so.

dnc

wrighty988

ok had car on ramps today it looks like this

sports cat on down pipe
cat on mid section just after the downpipe
then as th pipe bends slightly after that theres a small silencer it looks like
then bends back on to the prodrive back box

does this sound right?

1000rwhp

hello,my 54 impreza wrx v-limited jdm has 3 cats....i havnt taken any out and still has a lovley rumble....it has fujitsubo back box ,do you know if impreza wrx v-limited come with fujitsubo back boxes?

dnc

Unlikely that Fujitsubo back box is standard. Most likely fiited after-market in Japan. They are quite desirable over here.

dnc

dnc

Is your car the STi PPP? If so it should just a sports-cat in the down-pipe, no others. The std UK STi has a mid section cat in addition to normal cat in d/p. There is also a resonator box as you describe on both the std and PPP.

If your car is as described then you have bits of 2 or more different systems on it.

dnc

wrighty988

ah k the car is a sti ppp
i dont know why the car would have the cat in as you described but if the ppp is put on standard subarus after their built could it of just been an error and they never removed the cat in the mid section?

but i find it weird it has a prodrive sports cat and back box

dnc

Do you definitely have mid-section cat? I'm trying to think if the literally just removed the cat and left the pipe, or if a new pipe was fitted. Alternatively it could just be heat shields you are seeing? Have to have a look at mine later, let you know.

Back to your original question, what kind of power are you looking for? Do you still want a total decat? Sound?

dnc

wrighty988

sound aint an issue im happy with sound the car is standard would like it a little deeper but not fussed.

power - i remember fitting a decat to my focus rs and gaining around 15-20 bhp
so thought it would be the same with this.

ill get the car out sumtime over the weekend and take sum photos of the midsection and post up pics but im pretty sure its as i described

ah maybe this might help.....i remember when we looked there was a sensor going to the cat in the mid section

dnc

With your car just at it is you should be able to get 330-340 bhp and similar lbft by getting it re-mapped (don't think you'd go much higher by de-catting as turbo then becomes limiting). If you want a louder noise you could try getting a de-res centre section, freed up a bit more burble on mine.

Also, I think you may be pleasantly surprised by the noise of your car, have you ever let anyone drive by in it? I was shocked at mine. The Prodrive exhaustt isn't LOUD but it captures the burble very well, certainly when you pass the 2500 rpm mark (not too often then ). OK it's not going to split people's eardrums at idle but hey.......If you want loud, go full decat and get a Blitz NuR spec or RCM team ice, or just change backbox to either of the above.

The newage has more sound proofing than classics, which tend to be louder in the cabin.

TonyBurns

iTrader: (3)

You may gain 2 bhp by removing a sports cat, you will need to remap the car though, if not it could get terminal with your pistons

Tony