Cat Converters.

[one_and_only2004]

Righto, i've started looking at buying a new set of converters for my ute, and there's a lot of different sizes (2"/2.25"/2.5"/3"/etc.), So when i'm buying them what do i look for? I'm planning on running either a 2.25" maloo system, and if i can't find a second hand system i'll probably just buy a 2.5" twin and quieten the crap out of it.
Do i match the cats to the size of the extractors or the exhaust, or is bigger better? I understand the CPI part of the equation, it's just the size i'm confused about.

Thanks,
Julian.

[Not_An_Abba_Fan]

You just need to match the size to the rest of your exhaust.

People will tell you 100CPI are the best, but all they will do is make it louder, and they are illegal. The highest flowing legal cats in Australia at the moment are 200CPI. Magna Flow do them as well as some other brands. 200CPI cats flow up to 750 HP so they are more than adequate.

I can do you Magna FLow steel 200CPI cats at $198 each.

[GenReaper]

I run Balistic Cats on mine.

100CPI 2.5 inch in with 4 inch body, cant be more happy with them.

Sureflo Exhaust: Top Quality Custom Performance Exhaust Systems and LS1 Tuning

I believe they are about $216 each and they sound and flow awesome.

If you mention you saw the post at LS1.com you will get them cheaper.

If its only a 6 you probably wouldnt need 100CPI but thats up to you, yeah it will make it louder and flow more but hey put some good mufflers and a resinator on it and it will sound sweet.

[sweefu]

I thought that Ballistic Race Cats claim to be 100cpsi and legal?
Or are they hosting some false advertising?

[Not_An_Abba_Fan]

It doesn't say anywhere that they are legal.

[PRAVX II S]

Metal matrix are the best they are Australian made. Or redback again made in Australia.
I think your system is 2.25 from factory. So get the 2.25 unless your re-doing the whole system. And doing major upgrades to the motor.
Bigger is not better.

[sweefu]

It doesn't say anywhere that they are legal.

In a street commodores magazine it has their ad and then says australian legal, though maybe they are refering to the cat back system next to the cats haha sneaky sneaky

[one_and_only2004]

Yeah i wouldn't be bothering doing the exhaust again if i wasn't doing anything major. I've got a Raptor supercharger going on in about a month, and my stock cat is just short of rooted.
Thanks for all the info guys, I'll see how i go.