Lets play name why the muffler was loud
 

I bought a trashed project car and the exhaust was so loud that it rattled every window in the neighborhood when I unloaded it. I was told it had a fairly new greddy racing exhaust on it. I dropped the muffler to replace it with a racing beat twin I picked up and look at what I found. The first picture is just as it was when I dropped it out, the second is when I pulled at the edges of the holes to take a look. On inspection, the bottom of this muffler had a couple of small holes that had been jb welded and then was rattle canned with chrome/ silver paint. The shell of the muffler is 2 layers. The inner layer is metal the thickness of a coke can and the outer layer is very thin sheet metal like an old coffee can but feels almost like some kind of plastic. There is no name or numbers on the muffler. For such a crappy muffler the exhaust tip is very heavy with dual walled construction that weighs almost as much as the muffler and the muffler is fed by a very heavy, thick walled steel pipe.