Decat Up-pipe on WRX
 

Hi

Thinking of fitting a de-cat up pipe on my pretty standard UK 2001 WRX Wagon. Its got a 3" Japspeed cat back pipe and back box. Question is, will it still pass emissions tests? Looks like it would still have 2 other cats. What about CEL - any mods needed as current up-pipe has temp sensor in it.
cheers

Leave the uppipe alone, fit a sports cat downpipe and decat the rest from there back, then remap.

Hi,

Sorry to thread hi jack a bit, but Why not decat the up pipe ? I was under the impression by doing so would increase spool up of the turbo. I have an 03 WRX with decat centre pipe but standard cat in uppipe and downpipe, it has been remapped of course. The reason I asks is that I was toying with the idea of a harveys up pipe to help spool up of the turbo, not really for more power, but lower down torque.

Am I very wrong in my assumption ?

could you not just put an sti up-pipe on? they dont have the cat in place like the wrx up-pipes do...might be a cheaper option then aftermarket ones.

also yes it does aid spool, the efficiency to which it increases is dependant of the other mods along with the up-pipe though

I wouldn't leave the up-pipe alone. A de-cat uppipe will allow the turbo to spool slightly quicker but more importantly it will save turbo as the cats are known to break up and pass up through the turbo.

A de-catted/sports-cat down-pipe will give you more noticeable power increase over an up-pipe (after a remap) but you'll need to get a de-cat up-pipe also to be safe.

If you just de-cat the uppipe and center section the car should still pass MOT emissions, my bugeye did.

HTH

Ben

Even the STi decatted up-pipe may not gain you any spool over the stock pipe. Buying an ebay decat up-pipe will rob you of spool.

if you were to decat the centre cat, and leave the up-pipe and downpipe as standard, would u still need it to be remapped?

Thanks for replies and interest - clearly some divided opinions. May well leave alone for time being - didn't realise this would involve re-maps. Just wanted a "relatively" cheap up-grade and de-cat up-pipe looked A) Cheapish B) Easy to fit and as mentioned, would allow power to come in a bit earlier as the turbo spools quicker. Oh well:rolleyes:

Apparently the de-cat up-pipe is a massive job to fit and can take 1-2 days. I've been quoted nearly £500 today for it doing, I'm a few quid short of affording it and one Subaru forum is claiming it's imperative it's the first thing you should do to a WRX. The site also states a decent up-pipe will give 10bhp and spool from 500rpm earlier.

£500 for fitting up pipe,where in hell you are live matey,this cost average from £60-£100 top in Subaru Specialist.



Jura

Been to two very well respected local Subaru specialist today, I thought it would be £70 tops for a decent pipe and about 2 hours fitting £150 all in!

:(

Hi there no way £500 is too much,just have look here for recommended specialist not cowboys or contact here Harvey about the u pipe and will fit as well..


Jura

Just dropped him an email though I understand he's on his death bed :(

If he's in Darlington that's not too far.

But someone must work with him at garage..

Good luck matey.


Search here for people from your area,which tuners are good and which are just cowboys.


Jura

It's good mod. I've got the sti up pipe on mine currently as part of a big range I did at once. I'll be selling it in the next month or 2 aswell. Just a pain in the arse to get on and off.

Harvey Smith - £75 to fit an up-pipe! Just waiting on price of up-pipe now.

Harvey up-pipe is best out there and is proven...
Here are Harvey prices for Up-Pipe

https://www.scoobynet.com/trader-ann...t-uppipes.html



Jura

Pregnant wife lent me the money to get it and I wish I hadn't now.

how hard is it to get on and off the up pipe on a wrx

Not the easiest job to be honest, especially if the exhaust and turbo hasn't been off already. I replaced mine when I was changing the turbo so it wasn't too bad. Soak the bolts with wd40 before you start!

Hello mate its not a really hard job just undo the engine mount under the car and jack the engine up a bit and then it will come out with a bit of twisting. I fitted a cheap ebay Toyo sports full dacat system including up pipe around 8 months ago now had a remap by racedynamix making 278 bhp 310tq.There are a few other mods but paid £200 delived, sold the cats on ebay £160 thats £40 for full system :thumb:. I'm lucky though i have an MOT friend

I thought it was'nt that long ago you had a thread up, about your up pipe and the fitting of it ?:wonder:

STI, 2.5 WRXs or the up-pipe froma classic... all the same part number :)

This thread is 7 months old.

Do you need a remap if you fit an STI Up-pipe to a wrx? I still have the other Cats in place.

Yes you will need remap plus yours mapper must disable EGT CEL


Jura

i changed my uppipe for a sti uppipe on my03 wrx. it had to be mapped again for it.
from haveing the down pipe already decated it made no difference in spool up or power but i did loose 8bhp from 298 to 290, but it was mapped good first time round lol. the only benifit i get from a decat system is i can through a flame out lol.