Bypassing base exhaust Y pipe.

Originally Posted by POS VETT

Ok, color me curious.

I've been pondering over this trend among you guys, "Z people". Out there, when there is a V8 engine in a vehicle, usually of a domestic brand, the OEM exhaust tends to have a H-pipe (save for a few models). The aftermarket usually have X-pipe as an upgrade, or if the aftermarket company cared more, the crossover pipe is in the form of two nicely-siamesed pipes ala NASCAR which subscribes to the notion that this configuration is best at scavenging and equalizing exhaust gas flow-pressure-whatnots.

Now, the 370Z OEM configuration is in the form "double Y", perfect for merging pulses and maximizing scavenging effect. My NISMO S-Tune exhaust has this configuration while my DC Sport has very very nicely crafted, siamesed crossover pipes. From noise point of view, "true dual" and H configurations create an alternating pulse sequence between the tailpipes while the siamesed and X configurations create equal pulse sequence between the two due to blended and merged pulses from both banks.

So, what is the feature that becomes so popular with "true dual" exhausts in the world of Z cars? Is it the noise characteristics? Bragging rights? Popular belief? Please enlighten me.