Sorry for the noob question, but this is something i've been wondering about.

What is the diameter of the stock pipes from the cat to the mufflers? And what are the diameter's of the pipes on aftermarket exhaust systems such as those by Fujitsubo, DC, or Tanabe?
I'm curious about this because if the diameter's of the stock pipes and aftermarket pipes are the same, wouldn't it then be more practical to just replace the mufflers? I'd understand if the diameter of aftermarket exhaust systems were larger, but the same size? I dunno..

Hope someone can clear this up for me...

Thanks in advance,

-S

 

(copy and paste) http://sohc.vtec.net/article_files/117652/u13.jpg

See the Fujitsubo thread below... The stock sizes look like 2.5" spliting into 2.25"?
The aftermarket is listed as 60.5mm (2.38" inside diameter?), with a nice 'Y' weld. It also replaces the res.