zedf

Hi i have a my93 wrx import i was wondering how much bhp would increase by fitting a decat i have been told it has 2 cats on it is this right?????

Should i change both?????

Also how hard is it to fit???????

And does anyone have any pics of one?????

What is the downsides in having it on a car????????

Thanx.

scoobfan

Yes, it should have 2 cats

The increase varies - I have seen quotes of 40BHP but I'm not sure

Should I change both? - For maximum gains yes

How hard is it to fit - It's a garage job

Any pics of one - No !

Downsides - you will fail an emmisions test with a full decat, but that said..
your car is an early import so may not be recorded.

Rob

The rookie

iTrader: (1)

A 93 import car will only need to meet the non-cat CO test (4.5%) if it can't pass that without a cat its scrap anyway!

Simon

Stephen Pope

I thought it was only the UK cars that had 2 cats? I have pictures of the standard mid section if you want. I am unable to post them on here - too much of a spaz to use photobucket!!!

stephen.pope30@ntlworld.com if you want some pics.

hamyam

hi ive decated my centre section and planing on doing the down pipe tomorrow if my heat wrap comes in the post .I can take pics of the original pipes if you want

rmtypeR

As I understand it, the japanese classic imprezas only have 1 cat and that's in the downpipe. The bulge in the centre pipe is a silencer, not a cat.

The main power gains come from de-cating the downpipe.

In theory it's simple to fit - just 5 bolts to undo. In reality, the bolts are likely rusted on and I've heard can be a complete nightmare to undo. I'm going to pay Hayward and Scott £75 to fit mine.

bhp increase - without a remap I don't think you'll see that much - I'd say 10-15bhp for a full decat. I've got a Type R and I'd expect if I got a full decat AND remap I'd gain 30-40bhp - most of which would come from the remap, not the decat.

scoobfan

I'm sure that's only applicable to JDM wagons, but don't quote me on that

Rob

kingofturds

iTrader: (1)

Try it yourself and the when the nuts start shearing off take it to a garage

hamyam

ive got a 96 sti ra and have 2 cats one in the downpipe and on in the centre section

zedf

Email sent to Stephen Pope.

hamyam can you get the pics for me mate.

So some people are saying the wrx jap imports have 2 cats and some say 1 can someone confirm this who has either changed both or seen both.

Also does the cats make a difference to the sound of the car does it get louder?????

Thanx.

scoobfan

Yes, not only do the cats reduce emmisions they also act as resonators, so
the noise will increase.

You'll notice more of a burble and it may even spit flames, nice !!

Rob

Stephen Pope

More applicable to removing the 'main' front pipe. I did not notice any difference when removing my center one, the front one on the other hand.........it is worth it for the increased spool up noise alone!!!

pslewis

It will make it louder

Car has been mapped for CATS in place

Doubt if it gives much extra BHP - its a placebo effect

Pete

hamyam

cant wait lol

zedf

Sounds good are all the cats the same or does the name of the cat make a difference???????

hamyam

mines called pepsi

sharpydoo

i spent 4 hours trying to decat MY00 today and still have to finish it in the morning ffs. Would def not recomend this to a novice. Took hours just to get the heat guard off the turbo. Only sheared off 1 nut but managed to cut my arms to pieces in the engine bay. Lots of swear words to!!!

hamyam

cant wait lol

scoobfan

That's why a remap is essential after fitting Pete, to make the most of the gains.

Rob

StiX

iTrader: (4)

When I bought my MY00 a month ago, came with a dyno printout for 215.5bhp - standard apart from Magnex backbox and resonated centre decat.

I replaced the front downpipe with a Ninja Sports Cat, and changed the filter to a JR panel filter.

Powerstation last Saturday for remap:

before - 230bhp

after - 272bhp.

So the downpipe and filter released 15bhp (but the previous dyno sheet from a different place, so not an accurate comparison just approximate).

Remap released another 42bhp (Tek3).

Also, from looking at the dyno results on Scoobynet, Powerstation seem to have lower results than everywhere else. So either they are more accurate, or more conservative than the others - who knows.

sharpydoo

i finished decating MY00 today, car is now VERY loud with afterburner vortex. Also there is a faint burning smell (plasticy) could this be anything to worry about?

StiX

iTrader: (4)

Afterburner are perhaps one of the loudest - are you saying you think its unnaturally loud, as if something is wrong, or just you are surprised as to the difference?

My last subaru was a MY95 with full Ninja, and that was a fair bit louder than the Magnex I have now.

Not sure about the smell though?

sharpydoo

its not unnaturally loud, but im now going to be more worried about been pulled over and fined, whats the worst that can happen for loud exhaust?

The smell came into the car after about a mile of driving, then the smell went after a few mins, when i stopped the car i popped the bonnet and could smell like a plactic burning smell. I had to modify the heat sheild to get it to fit over the new pipe, hope this hasnt caused a prob :S

V4JDMSTi

iTrader: (2)

you always get a funny smell from fitting a new exhaust part. just had mine done as well and it lasted a couple of miles when at full temp then went away.

am considering putting the standard dv back on to reduce the risk of popping flames. don't want any wanted attention from mr policeman!!!