Muffler "back pressure".

[Fernando Mendes]

"The muffler is designed for straight through exhaust to MINIMIZE BACK PRESSURE".Would like to see an explain about this.Thanks.

[greg g]

High performance mufflers are designed to optimize exhaust flow. Engines are air pumps, the more air they pump the more efficient they are so freeing up intake or exhaust has a potential to increase performace. The other side of the equation is that some engines need back pressure to operate effectively. Since our engines are not high performance, high compression engines, both the pressence of or the lack of back pressure isn't much of a concern. Mufflers work by bouncing noise around inside, each bounce lessens the sound that will exit, high performance mufflers, eliminate the boucning around and as such much of the noise lessening. They use a straight through design so they do make for a less restrictive exit fo exhaust gasses, there for less back pressure. Unless you have raised you compression ration to above 10 to 1, I wouldn't worry about any effects except for more exhaust noise.

I am running a single exhaust with a Dynomax turbo flow muffler. This is not a straight through as it bends the exhaust gasses around a couple of times. It is not a quiet as the stock muffler, but is not as loud as Cherry bombs, Smithies, or other straight through designs. Just a matter of personal preference as to whether you want to listen to exhaust as you drive.

Rumble vs, Whoosh, your engine likely will not care a bit.

[Fernando Mendes]

Ok Greg g,congratulations for your explanation.Let's see if more and more of the PH forum members can give other ideas about this subject.Regards.