What Size High Flow Cat On Near Stock Exhaust?

[BaysideBlue]

Sorry for the newbie question. My mate has a N/A R34 (2.5ltr) manual, he wants to get a high flow cat and a muffler. What size cat should he get? Same diameter as exhaust or bigger? The current exhaust I think is 2 1/4", not sure if its factory or aftermarket. So 2 1/4" or 2 1/2" or 3" cat? The less cell the better yeah? Thanks for any help.

Edited March 2, 2009 by BaysideBlue

[Eug]

you would go for the same diameter cat as your exhaust.

[BaysideBlue]

you would go for the same diameter cat as your exhaust.

Thx. What do you guys think of this cat? Good price or should I spend less since it's only a N/A?

http://cgi.ebay.com.au/magnaflow-2-1-2-inc...A1%7C240%3A1318

[N-DAWG]

Sounds about right... my cat Magnaflow hi flow metal cat was around $249 in addition to my cat-back system.

[dori34]

as eug said, get it the same as exhaust size.