i no they look different but which one makes more gains? sounds best? weighs least?whays the real difference? thanks

 

Yeah your right Vqracer. Zippin, you must mean aftermarket catalytic converter, or high flow cat.

 

You guys missed the question. He already knows that. He wants to know if a catback or a y pipe will show overall bigger gains, which is more of a weight factor, and which one contributed more to a tone/volume change.

 

All of the "catback" systems for the Z are after the y-pipe with the exception of the dual systems (stillen/Borla) and do not include the y-pipe which is bolted to the back of the catbacks.

For the best improvements you should buy a catback system and a y-pipe, I have a Fujitsubo system and a Japtrix Y-pipe.