Ok I am going to be upgrading my header, cat, and exhaust system soon. Now I have a 2001 GSR and I was wondering if I am getting the JDM 4-1 will it make sense to buy the ITR carsound cat and ITR exhaust or will the GSR carsound cat and GSR exhaust work out better. Will the hangers on the ITR catback line up on my GSR? Thanks.

 

itr catback will bolt onto your car, no problem.

if you are getting the jdm itr 4-1 header, then yes, get a 2.5" carsound cat and then mate it to the itr bpipe. gsr exhaust system is crap - crush bent and tiny piping.

 

Thanks for the info. But also I didn't mean the stock ITR catback, I mean an aftermarket one. Most likely right now I'm either going to go Spoon N1 with T1R b-pipe or Apexi N1. I still haven't decided if its worth it to get the Spoon yet cause it cost a pretty penny more over the N1.

 

spoon n1 and t1r bpipe are 63mm and will flow well in conjunction with the jdm 4-1 and carsound cat. if you go with jdm 4-1 and carsound and apex n1, you're stepping down in terms of exhaust piping, which will restrict flow. if you plan to stop with those mods, i guess thats ok.. .but if you are going to modify your head then i would spend the $$ on spoon n1/t1r.

 

LOL you have just said what I have been thinkin all day, I think you just forced me to go the Spoon N1 route, because I do plan on doing my head in the future. Thanks for ripping a hole in my wallet, haha. j/k