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100 cell cat, how much restriction???
MK9R - 20/1/09 at 09:35 AM

If i put a 100cell cat in my exhaust system, how restrictive are these?? My car (zx9r) has been jetted and set up with current (catless) system, jut wondered how detrimental the cat would be.

progers - 20/1/09 at 09:50 AM

Very little if your punch a 2" hole through the middle of it

- Paul

procomp - 20/1/09 at 09:57 AM

Hi

Won't pass the visual inspection then though.

At a guess given that a 100 cell dose not realy effect the power of the engine on the dyno tests etc. And assuming it is of a large enough Dia to not restrict on surface area it should not make that much difference. But i would certinally still want to have it checked after fitting the cat.

Cheers Matt

MK9R - 20/1/09 at 10:07 AM

quote:
Originally posted by progers
Very little if your punch a 2" hole through the middle of it

- Paul


LOL! The supplier will supply a catless cat for £10 less

I was planning on doing this so i donlt have to modify the manifold:-


Trouble is how will anyone know its even in there, so is there any point?? Or i could do as Neil has.

MK9R - 20/1/09 at 10:09 AM

quote:
Originally posted by procomp


Won't pass the visual inspection then though.


fair point, but i have a 90 deg bend in the end of my can (like most), so how on earth are they going to see it without dismantling the system/can.

This is all so bloody stupid and adding cost for no reason! GRRRRR!!!

aka Keith - 20/1/09 at 10:27 AM

Austen, whay are you looking to add a Cat, is your engine year not exempt?
cheers
Craig

andylancaster3000 - 20/1/09 at 10:39 AM

quote:
Originally posted by aka Keith
Austen, whay are you looking to add a Cat, is your engine year not exempt?
cheers
Craig


For racing in this country next year, the MSA has decree that all saloons and sports cars must run a cat if they were built since 1999. I think thats the rule anyway, the 750MC are making all competitors in the cat-classes run them though if I've skim-read the rules correctly!



[Edited on 20/1/09 by andylancaster3000]

MK9R - 20/1/09 at 10:49 AM

quote:
Originally posted by andylancaster3000
quote:
Originally posted by aka Keith
Austen, whay are you looking to add a Cat, is your engine year not exempt?
cheers
Craig


For racing in this country next year, the MSA has decree that all saloons and sports cars must run a cat if they were built since 1999. I think thats the rule anyway, the 750MC are making all competitors in the cat-classes run them though if I've skim-read the rules correctly!



[Edited on 20/1/09 by andylancaster3000]


yep, all cars manufactured after 1999, what ever engine they run (even a 30 year old xflow) have to have a cat fitted, bloody stupid!

procomp - 20/1/09 at 11:06 AM

Hi

Yep a 90 deg bend on the end. But when asked to remove silencer they will be wanting to see the internals of the cat.

At the moment no one is 100% sure of how the MSA scrutineers are going to go about all this rubbish. From what i am hearing in certain ( non 750 ) championships visual inspections will take place just ensure that there is no unfair advantage gained by not having the internals fitted. Of course they are not concerned if they work but no advantage must be gained especially in one make type classes.

Cheers Matt

MK9R - 20/1/09 at 11:24 AM

if the can has got to come off to see it, then i'm thinking put my R1 can back on, with one of these cats welded on the front. It won't be pretty but will visually look correct. If i have noise issues on trackdays slip it off and put my nice big shiney one back on