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Has anyone made a custom exhaust for their car? I have planned what i want to make for mine, and i want to know if i can exclude the cat convertor, the South African R31's dont have cats, and they have more power due to this, so... i dont care for legality really, the permits will come later, i want to do the work while i can over Easter. Any help would be much appreciated.

Thanks

Nate =o)

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My oh my... must be something with newer cars then, i dunno what the hell a cat does, cep for make it lose power, and filter more crap thru, but its worth keepin it on there then. I made a very nice setup for my old 202 a while back with two - piece extractors joining to one with a single muffler before the diff curve, and a big hotdog at the back. Fully ricey, but the 202 was worked, so i didnt really care. :) 17" rims too...NOO!!! I Miss em :'(

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Yea, it doesnt say you have to have a cat, just that u have to comply with emission laws, and that the exhaust shouldnt exceed the volume of the std one by a noticeable amount... I dont know how some cars get over the pits... Ive done nearly all my work to my car this holidays :D Gotta get the permits now before i can drive it anywhere though :D

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Nate - a cat converts the exhaust fumes from being very poisonous to be being less harmful fumes. It reduces the carbon monoxide and hydrocarbons from being "emitted" from your exhaust. I think it is mainly for the environment. wow I remembered something from chemistry hahaha

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whats wrong with your curren kakimoto catback? i'd only replace it with a custom, if it was less than 3" or rusted out. if you're lookin for a full custom system, its gonna be $1000 at least. if you want to get the rest of the exhaust done (cat - turbo) just get that custom made, should be well under $400. custom exhaust just means its custom made, to how u want it, not an off-the-shelf item.

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bad idea.

If it aint broke don't fix it. Get the dump/front pipe done in stainless (should cost you no more than $450 for both fitted).

If you are evil, then have the old cat removed and stick a matchng 3 inch stainless pipe through the middle of it, so it looks like a fully functional cat from the outside.

BTW, the cat stops working once you use fuel additives (like toluene) and run non-factory fuel mistures. They die remarkably quickly on performance vehicles.

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Oh well, i dunno about the cat, but im fitting a custom exhaust, cat back...and so far... ive spent... $45 on 2.5" and 3" piping. :O But this is cost price, as im doing all the labour myself. Also, im getting the bends done at my dads work, they use an oxy torch or somethin the rather, with sand or something in the pipe.. to bend it and keep the same diameter right the way thru! Dunno how mandrel bends work, but this is basically the same thing, (maybe is :) iunno)

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Also, another good thing, is that marlows is asking for $40 for the adapter that goes between the air pod and the air flow meter. The bad thing with the marlows one, is the intake is SQUARE!!! This reduces the flow of the intake, because the square is smaller than the circular channel. Im gettin this done for nothin too :) just a plate with 3" exhaust pipe stuck on it. EZ! Next problem... heat shield...

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But then you run into droning issues when driving which will get pretty irritating. I have a kakimoto myself and they flow really well...thats all u need, if u want more noise just ditch the turbo-cat assembly, get a new dump and screamer pipe made up and ur set dude.

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