as above is there alot of diffrence ? cheers

 

Depends what car. Its always more noticable on turbos.

 

on a classic wrx

 

yes, will make quite a bit of difference, although it only has the one cat un like the UK models that have two.

 

seen as though it restricts the hell out of the car then erm...yep

good for nigh on another 40hp. You might need map looking at or tweaking to get it running optimumly though.

 

ive not long bought the car and had a look underneath today, it looks like a pipe straight from the front to a back box. no other boxes in between . cheers

 

The downpipe, the curved one from the turbo is the standard cat on yours. Should be able to tell if its a cat, as its normally got heatshields on it. If you can see that is the regular thickness pipe, then you do'y have the cat.

 

its just a thick chrome pipe from memory. i just had a look at a receipt i have here. it says "classic impreza open mouth downpipe £164,25" . which was bought 4 month ago. ill have a another look tomorrow but im sure it is a decat

 

thought my00 had 3, uppipe, downpipe, and centre

 

Good for around 10bhp, not a hope of 40, but there will be quicker spool up.

Tony

 

as above, i hardly noticed anything when i decatted my classic wrx (apart from noise) untill i had a power fc fitted. then i noticed a hell of a difference

 

Yes dirk, you have a nice shiny stainless steel decat bellmouth downpipe in place from a previous owner! ... At that price it sounds like an ebay special, but no bother: still just a mandel-bent bit of T304-grade s.s.

Best to get it mapped for, to realise optimum spool, performance, safety...

 

what about m.o.t times ?

 

It will invariably fail.

I personally take mine to Zen who have a OEM catted downpipe, pre-bolted up to a quiet system, that they just swap out for the MOT (using Ford RapidFit right opposite their premises, over the road!)

Okay, it costs about £40 extra every year for the labour to swap in and back out again, but is a small price to pay IMO for extra performance and spool from a mapped decat downpipe.

 

just looked at it , and it is a de-cat. as for the mot time ive got that covered so don`t need to get a cat. spoke to a mate of mines who is a mot tester and said he would pass it for me if its the only problem. cheers

 

The best of all worlds

 

So how do you get a standard sti from 265 to around 320 then?

de-cat inc downpipe etc
fuel pump
remap

Genuine question.

On my mates Evo his downpipe being removed and replaced gave him an extra 30hp or therabouts.

 

With a remap you would still get 300 plus with a cat on.

 

The imports have two aswel matey

 

Mine ran quite well with the sports cat on up to 360.....when the 400 upgrade was carried out we found that the very same sports cat began to suffocate the car. As soon as the sports cat was removed and running on full decat, my scoob became a different animal! Ofcourse the sound of the exhaust was a tad louder!

 

Not sure of MY97-00 cars, but pre-Sep.96 MY93-96 cars only have the downpipe cat IIRC. The centre just has a resonator (which looks a bit like a cat housing)... I think!

 

had a few classics now pre 97 and they've had the 2 cats mate

 

Really? Is the centre-section's 'bulgey' bit a cat, then?

 

My99 only has 1 cat. Centre is just a resonator.

 

LOL, I got the MY's round the wrong way

 

im not to sure on the 97's onwards but the pre's have the cats, Although the K and L plates dont need them for the MOT

 

mines a 97wrx on a R reg. Jap import. Should it have 2 or 1.

Ive managed to source an old Magnex 6x4 with a decat, and wouldnt mind it.

I hear they do and dont pass mot without the centre cat on, someone said to take it for a long run before mot get it nice and hot, but im prepared to have it fitted for mot to be honest, not the end of the world is it.

 

normally i would of said its got the two cats but im not 100% sure now from the previous posts.

 

My version 5 passes mot with just a sports cat downpipe.

 

hey folks!! yeah i bought my 95 import wrx with no cat and it failed at mot time so i just welded one in. but there is a fair difference in power and spool up with one in. so mines is coming straight back out lol