I bought my db8 gsr used from the original owner. He installed a comptech cat back on it around 65k. The car has 195k on it and i bought it when it had 180. The owner kept all the paper work and receipts for everything that was done to the car. From looking at the pipe i'm guessing 2.25 but i am not 100% sure, since it bolts to the stock cat that is a another reason i think it is 2.25 but who knows. I have the receipt from comptech for a b-pipe part# 240-122 and says "b-pipe s/s, gsr 4 door", but no size. I'm looking for the size because i Am putting a header on and want to know if i will need a 2.5 to 2.25 test pipe to bolt to the comptech catback. I love the sound of it and never will get rid of it so i really want to figure out how to do this and make it work. Thanks!

 

2.36" same as most carb eo headers for gsr/ls/gsr/itr's.

 

^^ Wrong, He's asking for catback.

http://www.team-integra.net/sections...?ArticleID=451

it's stated that it's a 2.25" piping. Only cause it's a straight through design. Get a 2.25" vibrant resonator and some flanges, make your test pipe with those if you want you car to sound good with out a cat.

 

I got that. The cat-back is the same as the header collector. I guess the header collector is 2.5 inner diameter then.

 

my problem is if i get a header with a 2.5in collector, a test pipe that is 2.5 on both sides will not bolt to the comptech catback since it is 2.25 correct? Being that the comptech is a stright through design, will ditching the cat cause it to get raspy?? I am going to see if kteller makes a test pipe that has a 2.5 inlet and has a 2.25 outlet.

 

Just make a custom test pipe out of a resonator.

I have a ITR jdm 4-1 which has a 2.5" collector. i my guy used a 2.5" resonator with a 2.5" flange on one side and 2.25" flange to my ITR catback. alittle back pressure is always good.