i'm wondering which is better...dual muffler exhaust system or single?

 

Dual exit looks a lot better on the FCs in my opinion. However, single exit has a higher HP potential(only about 3-5more hp though)...

 

why is that? I mean, wouldn't true duals be the least restrictive? I don't understand how a single could provide more hp...please explain, I'm confused.

 

Well, a dual requires that at least one of the pipes be routed across the body, meaning longer trip, more bends, and the hassle of dealing with the tranny and undercarriage. A single could be routed more directly.

Also, since a dual is basically 1 pipe per 650cc rotor, the piping would have to be pretty small, it's probably harder and more expensive to make an exhaust line of high enough quality out if 30mm piping that a simgle out of 50-60mm piping (have you ever seen "Performance Exhaust Tube, 1 inch diameter"???)



Finally, you're looking at more than twice the price (two lengths of piping, two expensive mufflers, more hangers, more of everything).



The only time a dual works better than an single is when the engine has headers on two sides (a V engine), then it's easier and smoother to route a pipe out of each header, along each framerail.



I've always thought that it was pretty silly for the Mazda gurus to run a dual output on a small displacement, single-side output engine. The FD design is much better and cleaner.

 

True duals, yes, but you would have to have a header that split off each rotor and ran all the way back. Really what you have with the rx-7 "dual" exhaust is a single exhaust that uses a y pipe after the cat to go to two mufflers.



so 3 inches, y pipe splits off to two pipes 2.5 inches. You would get more out of one single 3 inch pipe all the way back.



If you had a y pipe that was two 3 inch pipes it would be a negligable difference between the strait pipe (i guess).



So the answer is correct or false or all the same. I don't know of any "Dual Exhaust" kits for the rx-7 that use 2 pipes all the way back, all I have seen are "dual exit" exhaust systems for the rx-7 which share one pipe off the header and a cat.

 

I know a shop that could run piping all the way back from a race header (pipe for each rotor). Would this show power gains? I don't need a cat.