cat converter

[patrix]

just a quick question for a mate of mine, he has a vl turbo calais and recently bought it off sum dude in canberra, as it appears the exhaust has been modded, its 3" from the turbo back and runs to a hotdog and out to a rear muffler, no cat converter unless the hotdog is not a hotdog and is a cat but it doesnt have the holes in the bottom like my vn had but anyways, he wants to know is there anything wrong with getting a vn cat converter and putting two 3" to 2 1/4" reducers on the cat converter and then welding that up to the 3 "exhaust? he is worried the exhaust goin from a 3" into the 2 1/4" cat and then out to the 3" exhaust might be fair bad for it. any1 got any help or advice they can give him ? i told him to go buy a 3" cat but he is convinced into puttin the cat off the commodore if it wont cause a problem, another one of those money saving ideas anyways lataz

 

[camvyss]

2 choices.

1. Leave it as is, the cat has most likely been 'gutted'.

2. Get a 'hi-flow' 3-4" cat. But don't make the exhaust different sizes. You ideally want 3" straight through.

From a legal standpoint you must have a cat, but performance wise you don't. So if he wants performance no cat, if he wants legal go option 2.

 

[vinnywelsh]

Just remember, if he is caught running a car without a cat, the fines are pretty damn hefty

 

[patrix]

so if he did put the vn cat on, and has the exhaust goin from a 3 " to a reducer into a 2 1/4" cat and then out into a reducer again back to the 3" exhaust will that cause any noticable problems long term or short term, even tho its only like 250 mm long ?????

 

[camvyss]

You shouldn't make your exhaust different sizes no. Yes it can cause problems.

Noone has asked the question, why? Why does he want to use a Cat off a VN?

If he wants to save money, just get a cheap Cat that is of a matching size. Just try to steer clear of mixing pipe sizes through the exhaust.

 

[Bax]

Just tell him to save.. Having a 2 1/4 cat kinda gets rid of the purpose of having a 3" exhaust in the first place.

And yes, the fine for not having a cat is huge, I'd tell him to hurry up and get it asap.

 

[patrix]

lol he wants to use a vn cat just coz he has one lying around, but i have told him everything all you guys have told me and he said he will go get a high flow cat, he said to thank you all for your help