Difference between Straigh through muffler and none?

[CLennerton]

What is the difference between a straight through muffler and a muffler that is not a straight through? Which is better, or does it matter?

[03GT]

http://www.svt4u2try.com/Mystuff/Mustang_FAQ/exhaust.htm

exhaust write up..

[jobzombi]

Stright thru isnormally foudn in the cylindrical types of mufflers and none straight thru in the more rectangular type. None muffles the sound better as it directs the exhuast flow, and noise, around bends with walls wells outside the perforated tubing that absorbs noise, thus muffling it better. Sound travels in waves, duh, but due to muffler shapes sound can travel straight or bounce of the sidewalls of the tubing, straight through mostly muffles the sounds that bounce not those that traveler fairly straight through, thuis decreasing its ability to cancel sounds. Again the twists in the none version also cancels out the straight traveling sounds as on the bend it hits the wall.

[Silentwolf]

An oval, offset, straight-thru works wonders.

[CLennerton]

is there a performance difference between the two? Like from what I have read it seems that the chamber ones will be more quiet than a straight through, and thats about it....

[03GT]

varies from muffler to muffler. most of the newer chambered stuff is designed so well the differences in performance is negligable.

http://www.andersonfordmotorsport.com/media/rumble5.jpg

[kylemorg]

The chambered ones usually are a bit quieter since they block the direct path of the center of the exhaust flow and cause the noise to reverberate in the chambers. And like 03GT said, the good ones don't add much back pressure. You actually want a small amount of back pressure anyway for the engine to generate low end torque.