Re a 04WRX,

I wanted to get a racebox back box and straight through centre section (resonator section).

Due to financial constraints I was thinking of doing this then getting a remap a few months later. But I was wondering, if i went for a back box, centre section and Afterburner cat pipe how long would it be ok to run without a remap? and.......

1) how much louder would it be without the cat?
2) how much more performance would it make remapping it without the cat as opposed to with it?


Any replies greatly appreciated!


Cheers

 

JDM Version 5 wrx. Imported new in 1999. Standard apart from filter, straight through centre and back box. 78,000 miles. Never been mapped. So mines lasted 8 years so far.

 

Remapp neccesary if you remove all cats, but you should be absolutely fine with just a backbox and de-cat mid section.
Should sound quite nice without beng to loud.

 

Ran mine with a catted down-pipe for two years before the re-map, wish I'd done it sooner

Dunx

P.S. CEL came on as cat is different to a std set-up, just ignored it

 

if your only replaceing the centre section back then you will stil have the cat on the downpipe so a remap wouldnt be very necessery at first as it wont do a great deal performance wise. if you are having a decat downpipe aswell making it a full decat system then you will not have the same back pressure as you would have with the cat. this may cause your car to back fire a little and put extra strain on your turbo as it wont know why it has suddenly lost pressure that the cat was building up.

i would fit the exhaust and see how it runs. if not to much back fire you should be ok for a while but you may be putting alot of extra strain on the turbo and would advice a remap pretty soon.

 

I though there was a cat before the downpipe Looking at the picture

http://www.scoobyworld.co.uk/catalog...0557fbf59acbb1

I want to get a new back box, centre section then the cat pipe, and leave the downpipe as it is. How much difference would changing this 'cat pipe' make???


Cheers

 

Thats the exhaust layout on a new age IIRC.

I ran for a year with a Racebox rear box and silenced afterburner center section for 1 year without a remap.

I now run a full 3inch decat from Revolution with a H&S decat downpipe. It is about the same volume even though it removes all cats, sounds better, improves spool and frees up BHP.

I liked the race box but love the Revolution.

Damo

 

I've decated my 03 wrx ppp down pipe but i left the up pipe cat in until i get closer to my mapping

 

so have you left the cat after the downpipe?

 

it depends on what exhaust you buy as to what sections you have i think. and what model car you have. i know on my wrx 93 there is a downpipe with cat, then a centre section with silencer then the back box.

the exhaust in this link is split up into 4 sections when normally it is 3.

if you dont replace the downpipe as well you will not gain any extra bhp and just make more noise. you can get some pretty good kits on ebay that dont cost that much and normally with the downpipe doesnt cost much more anyway.

 

Just realised you are driving a new age...how stupid do I feel.

Damo

 

Pretty....I ould guess!

Changing the up-pipe on a 04WRX is more benefit than changing the downpipe...

Simon

 

No that was replaced with the ppp package

 

i dont have PPP

 

I run a UK 02 WRX. I've got a panel filter decatt down pipe then straight through to the back box - all Magnex. Been like that for 18 mths no remap and I run it on Tesco's unleaded.
You'll get lots of horror stories on here I take them with a pinch of salt.
My car runs sweet and I drive how it was meant to be driven

 

How do you find the Magnex middle section and back box? They seem reasonable enough pricewise. I haven't heard any reports on them though.


Damien

 

Sorry for the delay replying. Fitted the center section and backbox first and they fitted well and were reasonable at £225. Sound was good without being too noisy in the cab.
Once the downpipe was added it sounds even better much more aggressive but again without being too boomy. Lots of people comment on the fact it sounds really good and better than other Scoobies they have heard.
I'd recommend them

 

What bore is the Magnex? 2.5" ? And another stupid newbie question... what difference is there in a 2.5 and 3" system (apart from half an inch!) Is it model specific or power related?


Cheers

Damien

 

AFAIK a newage WRX has a cat in the up pipe, a cat in the downpipe, a centre cat, resonated centre section and back box. An STi has the same but no up pipe cat.

You'd be ok fitting a centre decat pipe, a performance centre section and back box with out a remap.

I see some people above have said it's ok to decat the lot without a remap but I wouldn't, be on the safe side.

Allan

Look for Gus The Bus on the scottish section, he has good deals on centre decat and centre section.

 

Here you go,
Cat Delete For New Age - Subaru Impreza Drivers Club

 

not sure of bore size but mine is a 2.5" which I think is bore size. The Magnex center fitted straght onto the standard downpipe. The decat down pipe is massive !!! but fits the center section also.