strange exhaust combo???

[drginger]

Stock back box, custom 3" straight pipe to aftermarket y pipe.

Anyone done this and know if it's any louder than stock??

 

I understand its probably not great for flow, just putting it out there!

[SteveM]

its generally accepted that the stock box is actually pretty good and its the CATs that restrict the flow.... i would imagine it would be a bit louder but its still going to have the weak spot where it joins the mid pips at teh back box end... this weak ness is the main reason most end up replacing with a new box

[14N]

Not done this (your combo) exactly, but here's what I did have (as it may help answer you query in part)

 

Initially a Japspeed K2 backbox, standard/OEM mid pipe and Y pipe.

 

I wanted more volume so I had a 3 inch diameter straight through mid pipe made (OEM is 2.25 inch). It didn't give me massive increases in volume, but it did give a much nicer, deeper and ever-so-slightly louder sound.

 

It was explained (and dumbed down to me) by the exhaust fella. My K2 was a chanbered backbox, so the gases (and sound) had to pass through various chambers before exiting the system. The OEM backbox (I imagine) is a similar design/construction.

 

Couple of pics here: http://www.350z-uk.com/topic/67814-me-and-my-zed-update-110813-engine-bay-tangod/page__st__120

 

My quest for more volume inevitably resulted in me finding and fitting a K1.

 

I still have the custom 3 inch mid section if you're interested

Edited September 18, 2013 by 14N

[AliveBoy]

I had japspeed decats, standard y pipe with a standard mid pipe with the mid box removed and then the standard back box, it sounded pretty nice, until I swapped it for a K2 box and then it sounded a bit naff