I got a 97 GSR and am looking into an 01 ITR catback. I was told that the GSR piping is ~1.8" and the ITR is 2.25". Can anyone confirm this? Anyone with this setup? Satisfied w/ it? Also, will the 01 ITR cat back bolt straight onto my cat and line up correctly with the hangers? Are the dimensions the same or do i need to do some sawing and welding. Let me know whats up .. thanks in advance.

 

i dunn0 if i heard right or not...but i heard ITR full catback exhaust system is different than a GSR

 

yes...it won't bolt on to a '94-'99 GS-R. you will need to have it modified to fit.
it will bolt on to an '00-'01 GS-R, though.

 

I was thinking about getting an ITR catback too. However I have an LS. I was told that the ITR catback would be a direct bolt on for my LS. Also, are there any differences btw the JDM and USDM ITR catbacks?

 

yes...it will bolt on to the LS.
as far as difference between USDM and JDM ITR catbacks...I'm not sure...but I don't think so.