I'm about to start tackling my exhaust system on my R1 indy and was wondering, are here any noise/emission benefits to be had depending on which side of the silencer the cat is fitted?
I would rather go for the set up that would assist the sound levels as I'm thinking the emissions can be delt with by playing with the mapping.
Any views?
Col

i doubt it makes much difference where the cat is for silencing,

BUT, for emissions cat's work best when hot, so before silencer is preferable.

Cats will not work far from the engine so you have no choice, as close to the block as possible, ie straight after the headers.

Ditto, just after headers, although pref hidden as they're pretty ugly and also a potential target for thieves. My sisters was sawn out when she parked in a supposedly secure all night carpark!

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Originally posted by tomprescott
Ditto, just after headers, although pref hidden as they're pretty ugly and also a potential target for thieves. My sisters was sawn out when she parked in a supposedly secure all night carpark!

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