I’m buying a g3 gsr header off of a member, but what size cat do I need to get it to fit up. He also has a 15.25" cat for sale too. I have a ls/vtec with b18c1 head…which shouldn’t matter to the question. What size would I need for it to match up with the correct length. I’ve searched a few sites like summit and JcWhitney but all their cats are different lengths. I do know that the g3 gsr header is shorter than the g2’s. Anyone have an Idea? If i really do have to make an extention I will, don’t really feel like it but i’m sure I can pick up some scrap stainless from work
what year? 94-99 and 00-01 use two completely different exhausts.
94-99…sorry thought I put that
you need a custom cat then. i think any production cat is around 4", maybe 6" short. i tried the whole 94 gsr header mod… then i realized it was short so i went back to stock.
I have the same set-up as you with a JDM GSR Exhaust Manifold off a JDM B18C…for now I am just using the stock cat with the 4" flanged pipe that connects to the exhaust manifold, but I had to drill new holes in the manifold flange in order to bolt up the cat…
Most exhaust shops won’t make this for you b/c they know what you’re up to and it’s “illegal,” but if I were you I’d but a megan racing or something test pipe for a G2 integra and cut it to take about 2" off, then weld it back together. I dunno what else to do b/c I’m going to buy a new header anyway, this is just temp. so I’m not gonna go all out with it you know?
hope that helps…
an extension shouldn’t be to much of a problem, i’m working at a machine shop right now, just waiting for a good scrap pipe…but I would rather use the cat he has if it’s long enough than go through that hassle…he didn’t have the header on his car, he’s selling it for a friend