mystic_magic

Hi, im after a little advice. I've had my Scoob a few months and was wondering about decats.

I have an 05 PPP STi with a re-map to 330bhp.

I *think* im right in saying the car has 2 CATs? - one in the down pipe and one further back.

IS there any real advantage to taking the rear one off? and would it require any further remapping?

Also if its worth doing if anyone can link me to the sort of decat pipe i'd need on ebay or some other site i'd be gratefull - im not sure if i need a specific one due to the PPP.

Thanks guys

bpm1588

If your car has the ppp you allready have a cat removed.all that remains is the highflow prodrive downpipe.it would'nt really benefit taking this off for a decat unless your looking plus 350 bhp sometime in the future and that would mean a bigger turbo etc

ian10

sti ppp's only have one cat in the downpipe which is 100cel sports cat

then a through pipe to mid pipe which has a resignator in not a cat you can change for about £60 on e bay which is straight through s/steel section with a true 2 1/2" bore the standard one is mild steel and is about 2 3/8 "

TonyBurns

iTrader: (3)

Your car has 1 cat, just the downpipe, the advantage of removing this sports cat is zero, the centre section is a resonator box.
Note that removing the cat in the downpipe will cause engine damage unless you have the car remapped, replacing the sportscat with a decat downpipe will still do nothing for you either.
Your only alternative is to have the car remapped, but then you will lose your warranty.

Tony

mystic_magic

Wicked thanks guys...

So would i see any benefits from the larger bore rear section?

And does this mean ill still be ok for MOTs as im not taking a CAT out??

TonyBurns

iTrader: (3)

Replacing the backbox wont do much, you need to replace from the cat back really to gain anything.
And the sports cat is good enough to pass the MOT otherwise they wouldnt have fitted it
I should also add that replacing the exhaust from the cat back "can" invalidate your warranty also.... its a no win situation really.

Tony

mystic_magic

So theres not much point in the "s/steel section with a true 2 1/2" bore over the standard one is mild steel and is about 2 3/8 " like ian10 said then?

ian10

larger bore centre section will fit your p/drive back box better aiding flow and sound will be increased slightly
if you want more power fit tubular headers then a map tweak will be required though, but will give you abpout another 20 bhp and better torque

mystic_magic

I dont really want to go down the route of a remap as the car had one not long before i got it.
Will i get a small power increase with the sound? would you be able to find me a pipe that fits on ebay as im clueless.. i had Pugs for tens years.. lol

bpm1588

mate imho i would'nt do any more with the exhaust unless your planing big turbo's etc.the gains you'd get would be nominal as its allready had a remap too 330bhp.plus it would mean another map tweek to make the best of any changes.

mystic_magic

OK thanks everyone.