Matt_Turbo_2000

Hi,

Thinking of buying de cat pipes if i took the centre cat out would I need to uprate the ecu? Is it better to buy a box type or straight through pipe? What power gains would I get?

If I took the front cat downpipe off and replaced it with a decat pipe would I need to change the ecu? What power gains would I get? Does it increase the noise of engine a lot?

Brun

MY?

Matt_Turbo_2000

MY00 Sorry forgot to put what impreza doh Turbo 2000 V-Reg

Danny B

Replacing the complete exhaust with a de-cat system requires no ECU upgrade but to get the most from the free flowing exhaust a re-map would produce even more power.

Power gains are here http://www.haywardandscott.co.uk/subaru/index.htm

And yes they are loud

N1 SPAN

Front cat will make the biggest difference and will still pass MOT's with centre cat in. Centre cat makes little difference.

I would potentially say 15bhp gains for both, most from the removal of the front cat. The difference is more on driveability. The turbo should spool up earlier giving you a much bigger power band. Less requirement to red line the car.

No remap required, but as with everything, the exhaust is probably your first mod, it will only spiral into thousands with remaps then 2.5l conversions etc etc.

Matt_Turbo_2000

Yes would love to spend loads of mods but I am only going to do the simply stuff first then get some money together and start having some fun

cinders

DO IT!....

I got mine done last weekend and the difference is has made (along side a Green Panel Filter) is great!!.... It gives the car a lot more driveability, the turbo spools up faster and the sound is awesome!.... Even when you're off-turbo, the throttle response is much improved. Best mod so far!....

I lagged mine twice using cooltek's lagging material, then sprayed the whole thing with their silver spray paint - this is because the downpipe is stainless steel and they normally sound a bit raspy - mine sounds mint, plus apparantly it keeps the downpipe nice and hot which helps the gasses escape quicker.... (in theory) Got some pictures if you wish to see?....

Next thing for me is to bung my Dawes Device on and increase the boost to 1 / 1.1 / 1.2 bar (depending on what knocklink and AFR says....)

Matt.

Matt_Turbo_2000

Yes some pictures would be good.

cinders

email me at mattyseeuk@yahoo.co.uk and i'll reply with the pics of the lagged downpipe and the middle section i fitted. all done very cheaply.