Sij

I've just come into this and was wondering if anyone has this setup, rather than the usual sports cat in the downpipe and decatted centre?

Does it get through emissions and is it overall less restrictive that having the sports cat in the downpipe (assuming its a 100 cell)?

L.J.F

iTrader: (31)

What year car is it on mate?

Sij

Newage, 2002

Stevesbluewrx

iTrader: (4)

Hmm,

I was toying with the idea a little while ago where I was going to run a full decat but get a custom made back box to run my sports cat in the rear.

This is the same set up on a WRC Focus hence why you see it glowing at the rear etc.

But was told by someone it would be a pointless excercise due to gas built up etc and back pressure could be affected so went against it.

To be honest mate I just passed my MOT with Sports Cat and I am running 453bhp.

Steve

Sij

I was just wondering whether the positioning of the sports cat would make a difference and if so, in what way?

Stevesbluewrx

iTrader: (4)

Not sure really mate.

From factory on a WRX your have the cat in the up-pipe making that three in total. In the STi you have two in total.

Can only suggest pre and post turbo readings with the lambda etc? So in your case would you want to put the cat pre or post second lambda?

Steve

Sij

Managed to find on another board regarding these cats, that they aid turbo spool up with the cat being further away from the turbo, but also that they do not get as hot, so maybe an issue come MOT, although this may not be the case with a 200 cell ones. I guess it would just have to be stick it on and check the emissions.

I'm still a bit unclear as to say for example having a ninja 100 cell cat in the downpipe would be better for performance gains than having a 200 cell in the centre pipe. With the other pipes straight through, vice-versa.

VinceW

my RS2K had the cat roughly where the middle cat on the scooby is. I had all the emission crap taken out of the manifold to aid flow and it was running high lift cams. Come mot time the emissions started high but as the cat got warmer they started to drop, then fell like a stone when the cat was up to temp. The cat has to be hot to work so the car needed to be run at reasonable revs for a couple of minutes to generate the temperature. For emissions nearer the ehxaust port is better as the cat gets hotter quicker.