For those of you who have replaced the stock resonator what is the inlet and outlet size. I plan on installing a Flowmaster Hushpower II series resonator. It has a 17" overall length and a couple of inlet/outlet size options. Is it safe to go with the 2.5" inlet and outlet when I order the flowmaster? I realize that the exhaust pipe on the Infiniti is metric and I will have to butt-weld the pipes to the resonator but I want to get close as possible. I know some of you have welded in aftermarket resonators so what did size did you guys get?

 

The oem midpipe internal diameters are just under 2.5", look up daveb's y pipe and midpipe threads, they include pictures of the internal diameter.

 

Thanks.