I would like to decat my down pipe but think for MOT etc the easy option is to go the sports cat route.

Firstly do you get almost the same gain as a decate pipe? Is it still worth it especially if you looking to remap? (I know not quite as good)

Secondly I have already a Nur Spec middle and back section would a Scoobybits Downpipe with Sports Cat, Ninja downpipe with fast flow cat, Tornado downpipe with sports cat or Revolution Hi-flow Cat be the best? Are there any others around the £300 mark that would be better?

Can someone explain what’s the difference between 100 and 200 Cells are and how many you would need to be MOT friendly.

Cheers

 

I have a Ninja sportscat downpipe. Sailed through Mot, no CEL light and car was quite a bit more rev happy !

 

Ive just put a 100 cell sports cat on(not a big name), the performance is a little bit less (after hayward & scott decat) as in the turbo doesn't pick up as quick, the subaru burble is clearer (big +)) and it flew through mot

 

Fewer cells means less resistance to flow of exhaust....

Mine loved losing the standard cats.... then after two years of CEL, I got a re-map and WOW !

Dunx

 

I have the Thundercat on my 03 WRX. Have had it on for 3/4 years and have not had any problems getting my MOT done. I cannot compare it as i never had a decat, i wanted mine road legal from the first mods.
And as a comparison, when i bought my Thundercat they were 595 plus vat!
LOL to that.

 

So its not quite as much of a gain compared to if I go full decat but still well worth it. Especially if I’m going for a remap later?

Just working out which to go for now, I have read some people have the Ninja one but not sure much about the quality etc?

Scoobybits Downpipe with Sports Cat
Ninja downpipe with fast flow cat
Tornado downpipe with sports cat
Revolution Hi-flow Cat
or
Other

 

I am running the H&S 3" DP with the 100 cells cat and I am more than satisfied. I had the same worries before I got it and you do feel a little diffenrence in lag, the turbo spools a little slower, but can't really feel any difference in power.

 

This thread on 22b.com is worth a read: 22B Bulletin Board: Prodrive Sports Cat D/P vs 'others'

 

LOL at your 2 years of CEL
I'm up to year and half, map due after xmas

 

A decat looks to be the ideal then but what about MOT's? Is it literally a case of putting the cat back on for the MOT?

If so once its been remapped with the decat pipe once the cat goes back on for the MOT does it not run badly?

At the moment the Ninja downpipe with fast flow 100 cell cat is the option im leaning towards so i dont have to keep removing it but if its that noticable maybe a decat would be best... Stuck now.

My center and bb are both 3" (NUR SPEC) and I have been told before that i would be best going for decat downpipe and putting the center cat back in if i want one. (jollygreenmonster i think said this) but would t pass MOT's with the middle cat and NOT the front?

 

Someone on 22B had a centre section made with two cats (sequential) in it. Though maybe it was a standard centre with an extra cat....

Dunno what the feeling was about power or emissions or WTF but it could be a way to go....

One "pipe" = £60.
2x Magnaflow cats = £200-£300 ?
Plus a decat downpipe @ £120ish

J.

 

Was looking at selling my NUR Spec back two sections which although nice are very loud and then going full H&S system Turbo back...

Decat downpipe, Centre pipe with cat and then back box... All depends if that would pass MOT and be legal? (is it only one cat for uk MOTs)

 

Ok sounds like the centre cat wont pass MOT so its back to H&S centre and back if i can swap my NUR SPEC and then just working out which would be the best downpipe and flow MOT friendly cat to go for?

 

My old wagon very nearly passed the mot on NO cats (we swapped over a mid section from an STi which didn't have a cat in it, but we thought it did at the time )

Couple of us gave our UK centre sections to Ken who got a mate to chop them and make a double cat'd centre which did the trick perfectly. Only issue I had with it was that it rubbed ever so slightly on the tunnel (which wasn't as tight on Ken's STi).

I reckon that mine would have passed with a single cat'd section, but I guess a lot depends on the engine in your car anyway (they're all slightly different anyway).

This time round I'm planning a sports cat 'cos I simply CBA fookin' about with swapping exhausts over from one to the other at MOT time.

I did wonder how easy it would be to build a centre section with sports cat plus a bypass pipe so you could switch it from cat'd to non-cat'd at the flick of a switch (copyrighted idea of mine in case anyone makes a mint off making these BTW )