I know, it's great, Mark, you should try it, LOL! From what I gather, OP bought the system mainly for the Y-pipe. Since the Y-pipe on the X is a different design to clear the xfer case, it's pretty similar to the HR-Y, so that's what I thought you were (mistakenly) referring to. If not, my bad. The X sedan middy, OTOH, is not at all the same as the Z - it's like all other sedans so not a 'similar design' to the HR 350Z middy at all. The HR middy, as far as I can tell from the one I bought and sold recently, is like any other Z mid-pipe.

OP, hope that's not confusing to you...if so, ignore it!

 

So is that extension from mynismo.com posted earlier the correct one? I also saw that it would need major modifications on the muffler or am i mistaken?

 

This is the one I purchased and it fit perfectly

http://www.mynismo.com/products/?id=4404

 

My friend emailed me and he has a Mid pipe off of his hr 350z and I was wondering would I gain anything (sound and/or performance) by putting on this mid pipe plus the extension?

 

Simple answer, no.