Alright, made some calls and no one could help me so maybe you guys can. I replaced my stock cat with a Arospeed test pipe and I'm wanting to put on a Greddy Evo 2 catback system. I know the Evo 2 is 60-70mm but I'm not sure what the dia. is on the test pipe. I called Arospeed and the guy said it wouldn't work, but he sounded like an idiot. Is it that important to match the diameter of the two pieces? Will it work?
CC

 

Well, its important, but if your test pipe is 2.5" in diameter, and say the exhaust is 2.25", you should be fine or visa versa. I mean unless its like 3 and a 2 inch pipe, you have to get a coverter piece of pice that fits the two together.

 

Heres what I was thinking..... If the test pipe is made to fit factory and the Evo 2 is made to fit factory then why wouldn't it work. Correct me if I'm wrong but probably the best thing to do is measure the test pipe to get accurate measurement and see if it will work with Evo2.

 

Just to let you know that test pipe are not street legal in the 50 states but you might be in another country.