Clarkie172

I need to clear this up, I have been confused since looking at Subarus! On my 05 sti, is there:

an uppipe with no cat.....onto the turbo.....
from there, is it a downpipe with cat
then another pipe with a cat
onto centre section
then back box

Im a retard, can someone please break down my exhaust system!!!

hoskib

iTrader: (1)

std (non PPP), just as you described. except the centre section is sometimes referred to as a resonated section as it has a baffle thing to cut back the noise a little. a replacement is just a straight through pipe.

like this Subaru Impreza Exhaust decat downpipe, centre section, sports cat. :

PPP has a sports cat downpipe, then straight through cat replacement pipe, then original resonated pipe then backbox.

the up-pipe bit i'm not too sure, it hasn't got a cat so no need to change it for normal mods, but other than that your guess is as good as mine

Clarkie172

Will I fail an mot with this...... Decat downpipe, second cat left in, resonated part left in and then Vortex back box? Ie leaving one cat in? Im after good gains but still legal. Or is it worth just getting sports cat and decat the rest inc straight through centre section.

I think I read somewhere that someone got 310bhp with just a backbow,fuel pump and ECUTEK???????

ChrisSTI8

I've just had my car MOT'd a few days ago and only just passed on the emissions idle test. Fuuny but checked the mot from the previous year and it had "not checked" on the idle part of the emissions test. So car has passed 2 mot's like this. I'd put the std backbox as very quick tochange so not worth risking failing.

Car STI 03 with decat down pipe and the standard all the way to the backbox included. Ecutek'd and switched to 1 bar map.

Just got to put the vortex back on now and the centre decat section again.

You'll get more than 310bhp more like 330-340 but the big improvement is in the torque, response and a much wider power band to play with.

hoskib

iTrader: (1)

there was a thread a while back where someone wanted to remap with fully std exhaust, i think 300 was the most expected. you might get that figure with certain JDM models, but not with a type UK.

personally mate unless you're chasing big figures you'll not go wrong with a sports cat downpipe and decat. the resonated pipe doesn't do a lot for power increase, it just makes things a little louder

do this lot with an uprated fuel pump and air filter and you'll see between 320-340 depending on who does it and what rollers it goes on and like chris says it makes it a much more enjoyable car to drive

Clarkie172

yeah I want to do it mate just thinking about which way! I cant be bothered with mot hassle! I want it to sail through! If I get sports cat, that replaces only the downpipe doesn't it? Can anyone show mw a pic of the second cat? The one after the downpipe and before resonated centre section

Many thanks

hoskib

iTrader: (1)

a sports cat with no other cats will fly through an mot mate
if you want a pic of the std 2nd cat i can sort one out for you, are you not sure what's on your car?

yeah, a sports cat normally is just the downpipe.

Clarkie172

Im slowly getting to grips with this! haha
I'm on the look out for a sports cat then and decat everything else!

Clarkie172

does something like this replace the cat in the downpipe and the 2nd cat?

SUBARU IMPREZA WRX STi DE CAT DOWNPIPE EXHAUST DECAT on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 13-May-08 21:29:03 BST)

ie all you have after this is a centre section and backbox

hoskib

iTrader: (1)

looks like it, but you won't have any cats in the system so you wont' get thru an mot

if the 2nd cat alone does pass then you'll need something like this SUBARU IMPREZA NEW AGE WRX STi 1ST DE CAT EXHAUST DECAT on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 12-May-08 19:15:00 BST)

if i was shopping for a system it would be something like this:-

STI PPP SPORTS CAT DOWNPIPE (subaru impreza prodrive) on eBay, also, Subaru, Car Parts, Cars, Parts Vehicles (end time 11-May-08 14:09:32 BST) (although the later design is without the jacket and open mouth is considered slightly better)

SUBARU IMPREZA NEW AGE WRX STi DE CAT EXHAUST DECAT on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 13-May-08 21:29:06 BST)

Subaru Impreza Afterburner Decat Centre Section on eBay, also Exhaust Components, Performance Tuning Parts, Car Tuning Styling, Cars, Parts Vehicles (end time 13-May-08 16:51:01 BST)

and then it's down to your choice of backbox

but if you do start changing downpipes and 2nd pipes bear in mind you'll need remaping, so work out a budget and what you want from the car and buy it bit by bit and get the work done in one hit as it'll work out cheaper in the long run

Clarkie172

thanks for your help mate!

I think I'll look out for a sports cat then and the decat pipe and centre section! Then as you say, get them fitted and remap done at the same time!