Aftermarket Catback Exhaust Piping
 

I was looking to gather more information about the available catback exhausts before making my purchase, but I found that the exhaust piping was a little harder to find as it appeared the manuafacturers does not like to advertise it in their descriptions. I finally found all the common brands and made a list. I'm sure this information would help others in finding the exhaust to fit their needs. Owners of specific exhausts, feel free to correct any mistakes.

Stock OEM:
57mm or 2.25"

NISMO:
62mm or 2.44"

Invidia Gemini:
60mm or 2.36"

Fast Intentions:
65mm or 2.55"

Ark:
65mm or 2.55"

Berk:
65mm or 2.55"

HKS:
60mm or 2.36"

Tanabe:
70mm or 2.75"

Greddy:
60mm or 2.36"

Stillen:
65mm or 2.55"

the Greddy SE is 60mm and the Greddy Turbo Ti-C is 70mm

Stock and nismo (of the nismo Z anyway) bottleneck in the y-pipe/h-pipe though. i think to around 1.5 inches... i think.

OEM y pipe is 2". Your list is incomplete because piping inlets and outlets can differ at different parts of the exhaust. Also, I believe its already been mentioned that GREDDY ti-c is 2.75" and very loud.

Let's make this list accurate and more complete.