So just in case I was thinking of upgrades for my car

[iain85]

Would a Sti sports cat and a Wms Decat up pipe from a blob eye be any good for future upgrades for my 04 wrx.? Also been offered a pro drive back box for 45 quid.
Are these any good for future upgrades?

[SpecB]

As far as I know the STi cats are the same as the WRX unless it's a PPP downpipe with sports cat. the up-Pipe could be a good move as it'll decat but beware some are too large a bore and actually adversely affect spool. Prodrive box is a nice piece of kit, free flowing but quiet and subtle.

[iain85]

Cheers,
Is £45 a good price for a back box?

[Steve_PPP]

£45 is a good price for a prodrive backbox, yes.

Are you sure your uppipe has a cat in it? I'm sure some of the blobeye wrx's ended up getting straight through pipes like the STIs but i think it was only the later cars. All of the bug wrx's certainly had cats in their uppipes, but worth checking. As Nick says, don't get an aftermarket one with a bigger bore - worth looking for a genuine STI one as bigger isn't better for an uppipe....

And in terms of sports cat - if its off a STI PPP, then its a good upgrade but will require a remap. If its a standard STI cat, then there's no difference over the WRX one you'll have already (assuming your car is standard).

[iain85]

Hi steve,

I have no idea about my up pipe tbh. Is it something easily checked?

So there's little difference over the wrx cat then? Il ask and see if it's a ppp model.

Here is the link to the ones I'm looking at

http://bbs.scoobynet.com/subaru-part...at-uppipe.html

[Steve_PPP]

Sorry, just realised my post didn't make sense but yes, the standard Subaru cat on the wrx and sti are the same unless the sti had the PPP sports cat fitted.

From that Scoobynet link - its definitely a sports cat so would be a good upgrade for you. The second pipe its bolted to with the heatshields looks like a standard centre-cat, but it could actually have a straight through pipe under the heatshields - also fitted as part of the PPP (which would effectively remove both the downpipe cat and centre cat from your car). Remap definitely needed.....

Re: uppipe, that WMS one looks pretty fat. The bigger the pipe, the slower the exhaust gases have to flow through it and the longer it takes to spool the turbo. I'd personally avoid and look for a genuine STi or Harvey uppipe.

[iain85]

So should I ask the seller if the centre cat has a straight through pipe fitted? If not is it still worth buying?

So assuming I found a standard Sti up pipe and got the pro drive back box/panel filterI'd be good to go for a remap ?

Thanks steve

[SpecB]

The downpipe is worth getting, decat link pipes are cheap enough new tbh. I'd get an up-pipe from Alyn (Harvey Smith spec) or a standard STI one. The other option s to 'de-cat your up-pipe.

[iain85]

Ok Ta, il see if he's up for posting it.