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Muffler Anatomy 101

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I had to replace my muffler due to an annoying rattle after warm-up. I was curious about what might be rattling so I cut it apart to see what’s inside. I was also curious if there were any easy ways to improve sound, preferably reversible or adjustable. Here’s what’s inside:


If you cant tell from the picture, here’s what goes on in there: Exhaust gasses enter through the inlets and get strained, buffered and baffled inside the center three sections, and eventually migrate to the outer sections to where the outlet pipes are routed.

I can see that it would be quite easy to drill some bypass holes near the outer ends of the inlet pipes but making it reversible or adjustable would be complicated.

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People have put a tool into the inlet pipes and cut holes. Muffler does not need to be opened up like you did for this type of mod.

There is at least one German guy who cuts open the muffler like you did and something is done to the insides. http://www.renntech.org/forums/index.php?s...hl=frankenstein His name is Andreas Herrmann, and he would not tell me what he does. His modification is unique. He modifies the chambers. He adds bypass tubes, and those tubes have valves. This was at a time when Porsche was slow in coming out with a sport exhaust for 2003-2004.

Then there is the Oettle flavor, another German. http://www.renntech.org/forums/index.php?s...5&hl=bypass This is simply bypass tubes welded on. It mimics the old style factory sport exhaust, but is is not. The bypass pipes on the factory sport exhaust do not run from the inlet.



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I had to replace my muffler due to an annoying rattle after warm-up. I was curious about what might be rattling so I cut it apart to see what’s inside.

What is the thickness of the stainless outer shell? --Brian

It's a double layer of sheet metal, each about a millimeter thick.

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