Decat Up-pipe on WRX
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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
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
#3
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 ?
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 ?
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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
also yes it does aid spool, the efficiency to which it increases is dependant of the other mods along with the up-pipe though
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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
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
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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.
Last edited by bluenose172; 08 November 2010 at 09:04 PM.
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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
#9
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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.
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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.
Jura
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Here are Harvey prices for Up-Pipe
https://www.scoobynet.com/trader-ann...t-uppipes.html
Jura
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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 . I'm lucky though i have an MOT friend
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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.
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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
also yes it does aid spool, the efficiency to which it increases is dependant of the other mods along with the up-pipe though
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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.
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.
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