new cats for au xr8

[redauxr8]

Im eyeing off a couple of magnaflow cats on ebay... What size should i get? My mate also has an au 5 litre and is interested. He has stock exhaust, i have a 3 inch lukey..... Can we both get the same size cats? And wat size do u guys recommend?

Worth buying off ebay u reckon?

Cheers guys

[RG]

Originally Posted by redauxr8

Im eyeing off a couple of magnaflow cats on ebay... What size should i get? My mate also has an au 5 litre and is interested. He has stock exhaust, i have a 3 inch lukey..... Can we both get the same size cats? And wat size do u guys recommend?

Worth buying off ebay u reckon?

Cheers guys

Personally I wouldn't (and won't next time) go past the 100cpsi Ballistic Cats from Sureflo. They have a forum here as they are site sponsors and they are really well priced.

[redauxr8]

My bro has a 3 inch zaust and headers and i have a stock zaust... we both have au xr8's Anyway, can we both get the same size cats? Can i get a 3 inch cat for my stock zaust? im upgrading my zaust a bit later to 3 inch.... can i re use the cats?

[shazaam]

Originally Posted by redauxr8

My bro has a 3 inch zaust and headers and i have a stock zaust... we both have au xr8's Anyway, can we both get the same size cats? Can i get a 3 inch cat for my stock zaust? im upgrading my zaust a bit later to 3 inch.... can i re use the cats?

Not to get too off topic, but what does your bro think of the 3 inch exhaust? Is it a 3 inch single system? I've been contemplating one but thought maybe a single system on an 8 would be restrictive.

[redauxr8]

The single 3 inch on his car sounds awesome, apparently hes been told that 3 inch is to big... But he loves it, and compared to my stock xr8, (we have EXACTLY the same cars) it goes alot better. It has more "go" than my car throughout the rev range so even though people say u lose low down power with 3 inch, they are usually just comparing it to a twin 2 /12.... Im definatly getting 3 inch single... Lukey Growler!

He also has lukey headers and custom CAI... But hes giving me the lukey headers cos hes getting pacmakers

Cheers mate hope info was helpful

[AUbigfoot]

If you have the money to spend on a high flow cat and are pushing some power, its not a bad idea. From what I've read, sureflo seem popular (for a reason maybe). If they are a site sponsor, I would say it would be good to go through here rather than bother with ebay. Support those who support us!

Most of the time, a 3" isn't needed for most daily runners but 3" comes in handy for boost etc.. It may be different for an XR, but in my experiences it wasn't required and as a result I run a 2.5" single lukey and it sounds the goods.

**Bare in mind, I'm no car expert, only what I have learnt from recently coming into the car scene.**

[Cooper69S]

Originally Posted by redauxr8

My bro has a 3 inch zaust and headers and i have a stock zaust... we both have au xr8's Anyway, can we both get the same size cats? Can i get a 3 inch cat for my stock zaust? im upgrading my zaust a bit later to 3 inch.... can i re use the cats?

keep in mind that a 3" exhaust on a v8 will not need 3" cat converters. at most you'd get 2.5", and then you'd probably need to get a custom y piece made up to join the twin 2.5 into the 3".

you can usually also get the extractors modified to be close to 2.5" at the outlet so you get no restrictions all the way through.

Theoretically, a 2.5" single exhaust is enough for a stock 5L, but I used a 3" and the sound was great (used two mufflers, both straight through, so nice and quiet at idle or cruise but great note when it opens up - you can hear it in the video here). Also I picked up about 10-15rwkw right through the rev range going from 2.5" to 3". if you plan any major mods for the engine later, a 3" might be needed. Twin 2.5" is good too. different sound to a single system.