Here is what I am trying to do. Right now, I have resonated test pipes going into the stock OEM exhaust: oem y-pipe, into oem midpipe, into oem muffler.

What i would like to do is get an aftermarket y-pipe and midpipe (with wider inner diameters than the stock parts), and keep the OEM muffler. Is this possible? I think the only issue would be finding an aftermarket midpipe that will bolt up to the stock muffler, as most midpipes I have seen as part of an aftermarket exhaust have a completely different design than OEM and wouldn't bolt up.

Can anyone tell me of a midpipe to make this work?

 

Looks like the Japtrix midpipe would work, but I believe it is for the 350z so it's shorter.. I'd need an extension as well.