I am making a custom exhaust system for my ITR and the question is what size of the pipe i should use, 2,5" or 3"?. My car is NA and almost stock except the intake . I am only going to buy the exhaust manifold, race cat and muffler. The rest i am going to make out of stainless steel pipe. The other question is how thick the pipe walls should be for optimal weight?

 

Anything bigger than 2.5" on a mildly built setup will end up causing more harm than good. Stick with 2.5", you won't be dissapointed.

The wall thickness should be whatever you are comfortable with. The thinner the wall, obvioulsy, the more risk you run of denting the pipe, or even puncturing a hole for that matter.

 

With the amount of companies out there that make exhaust kits for the Integra, I bet it would save you money and hassle to just buy one.

 

I dunno rob. I know someone who has their own fab shop who could make me one cheaper. The things I would be looking at is the fact that the manufactures out there have proven products. They have R&D behind their products and dyno sheets to prove it. But one of these days for curiosity sake I may have them make me one and compare on a dyno.

 

If I told you how much I paid for the BCIII in mint condition, You would be surprised.
If the classifieds are searched well enough I bet he could find a exhaust system for a really good price, mint condition and pretty easy to get/shipping.

Fabbin up an exhaust if you don't have the stuff in your own garage will be and can be a PIA. As for a pre-made system like Kteller- I still think it would be better then 'homemade'

 

I'd be curious how easily the SMS system could be reproduced because aren't those built to order?