Will a high flow cat make a difference?

[someguy360]

Hi Guys

Just had my new exhaust system installed Pacemakers through to a 2.5" single high flow muffler system and it sounds great.

Just wondering if it would be worth replacing the stock cat converter with something like this
SS304 2.5" High Flow Metal Cat/Catalytic Converter 100C | eBay

Would be nice to make the exhaust a little louder than it currently is and would help with flow/power a little?

Just wondering if I will get any power/sound gains by doing this

Thanks

[RIDE:42]

If you are going to run a cat put one on thats legal that is a pre cat Cheap way out put one on that is off a manual v8 (auto ones 2.25 m6 2.5)

[wraith]

100CPI is illegal due to emissions. 200CPI is legal. Sus out ballistic racing their cats are top notch. 8's and 6's have the same cats. You think Holden would bother spending the money on two different ones (talking VS here)

[TI3VOM]

If your cat has never been changed there should be a gain/restore in power as it will be blocked with built up carbon deposits, cats are meant to be replaced at around 50,000Km's supposedly.

[Crazy_C]

My VS 3.8 Ecotec has no cat in it, and it is glorious to drive, but it's an import here so the regulations are a bit more lenient.

[QldKev]

I'm not 100% sure of the info for a VS V6; but I can tell you for a LS1 setup which I assume would be the same.

The stock one has 400 cells per square inch. Both 200 and 100 are illegal. From my research a 100 cpsi will fail an emission test; but generally 200cpsi will often come in close on the limit. Also 100cpsi you will smell fumes from it, and I know a few guys who have swapped them out for 200cpsi.

On the LS1, a big restriction is not necessary the cat, it is the pipe heading into it. It is only 2.25inch but has a really bad crush bend in front of it; making it as good as a 2inch pipe, the VS may be the same.

The less CPSI the better the cat will flow. By changing you will get more hp and a louder sound. Don't expect to find a lot of power thou, unless your current cat is blocked up the shit.

QldKev



QldKev

[tosue]

piss on the bck wheel

[Not_An_Abba_Fan]

Only some 200 CPSI cats are legal, not all of them. I do the MagnaFlow steel 200CPSI cat, and it is legal. It is one of the few that come in under the EPA emissions limit.