stevie_ruc

Up pipe down pipe...whats it all about?

Which should i get first? do i need a downpipe if im getting a turbo back exhaust?

and finally 2.5" or 3" exhaust/uppipe/downpipe

Any help appreciated

stevie

powerwrx

iTrader: (11)

if your going turbo back then you will need to get a decat down pipe, (dnt quote me) but i think they are 3" tapering down to 2.5" to fit your standard pipes,thats if your going to stick to the standard size exhaust, or go for a 3" all the way through.also if you are going to get a full decat system then a remap will be recomended i would think

scoobyjay7

If you are getting a new exhaust turbo back then yes,
Your down pipe is your fist pipe off your turbo. Then next question for you is cat or de-cat, my advice is de-cat (gasses flow better).
As for your up pipe, this is the first pipe to your turbo off your headers (manifold)
So for best results you will want a de-cat up pipe, then de-cat down pipe, de-cat centre section then back box of your choice(how loud you want)
All in 3"

ian10

what model and year ?
what power are wanting/running ?

exhaust- if below 370 bhp 2.5 inch is fine
decat down pipe- makes no noticeable power difference to a sports cat (eg prodrive), and aren't m.o.t friendly.

up pipe- if your car is wrx 2002 on, it will have a cat in it , if its a sti or earlier than 2002 it won't.

i wouldn't change unless, it has cat in it, then go for a sti one or a magnex with 40mm diameter bore, for good turbo spool up.

stevie_ruc

its a 2004 STI PPP.

So i need a decat up pipe 3"

and a 3" turbo back exhaust, 100 cel cat maybe?

Wantin about 350 -400 eventually

scoobyjay7

Yes mate
Plus a re-map then you will start to get close to 350 bhp.
But for 400 bhp you will want something like a AFP5-20 or a tdo5-20g with supporting mods

Granby

iTrader: (5)

No you don't need a decat up pipe 3" as the STi up pipe doesn't have a cat in it

As for the rest i'd go 3" turbo back, 100 cel cat in the downpipe will save any hassle at MOT times

stevie_ruc

OK thats great. Thanks for all your advice guys

Anders_WR1

iTrader: (8)

Hello mate, there's a group buy on Hayward & Scott exhausts at the moment:

https://www.scoobynet.com/group-buys...ll-models.html

A full 3" system (no CAT) is £460 + VAT.

Cheers

Anders

stevie_ruc

mmmm group buy sounds great. Thanks again