Ok, before I begin I would like to state a couple of things up front that I am assuming as fact, namely: There's no compelling reason to modify the factory exhaust system, doing so will result in no improvement in engine performance, loud exhausts are mostly just annoying, and removing or defeating emission control equipment is both illegal and bad for the environment.
With that disclaimer out of the way, I was able to acquire a complete used 1100 exhaust, from the headers to the muffler for a measly 100 bucks, so partly just to satisfy my curiosity and with a view toward possibly building a straight pipe system up to the stock muffler for off road use :| I commenced cutting it apart yesterday. What I saw I found interesting and figured I would share in case anyone was ever curious what was inside there.
I assumed that the exhaust first flows through what looks to be a fairly large catalytic converter, through a muffler and then out the tailpipe. What I found is that there are actually three separate chambers with a fairly complex path for the exhaust to get from A to B. Some photos for visual reference:
First exploratory cut:
Looking toward the catalyst chamber. The perforated pipe dead ends there.
The same two pipes in what I'm calling the intermediate chamber:
This is the catalyst itself - it's actually pretty small.
This is the inlet side of the muffler:
So the exhaust enters through the catalyst into the open cat chamber, then into a pipe which goes into the open chamber of the muffler (bypassing the second chamber) through the pipe on the upper right of the last photo. It then filters through a perforated pipe backward out the port (on the left above) into the intermediate chamber, where it filters into a smaller perforated pipe (seen in the first two photos) which send its 180 degrees back again, not into but through the muffler (lower, smaller diameter pipe above) and direct to the outlet. There is no sound deadening material at all that I could see. I'm not an expert in acoustics or fluid dynamics or, well anything really, but I assume all this is to reduce the velocity and/or pressure as well as to create areas where some wave interference can tune out or dampen certain frequencies (?)
Anyway, all this is just offered as a curiosity mostly. I will probably run my inlet pipe from where the cat used to be and add a section to the body of the muffler to create a chamber where the exhaust can loop back from the inlet tube to the outlet tube. Again, all this is just an experiment; if I like the way it runs and sounds I may leave it (for off road use) and if not I still will have my original, entire unmolested exhaust system that I can swap back on in ten minutes or so.
With that disclaimer out of the way, I was able to acquire a complete used 1100 exhaust, from the headers to the muffler for a measly 100 bucks, so partly just to satisfy my curiosity and with a view toward possibly building a straight pipe system up to the stock muffler for off road use :| I commenced cutting it apart yesterday. What I saw I found interesting and figured I would share in case anyone was ever curious what was inside there.
I assumed that the exhaust first flows through what looks to be a fairly large catalytic converter, through a muffler and then out the tailpipe. What I found is that there are actually three separate chambers with a fairly complex path for the exhaust to get from A to B. Some photos for visual reference:
First exploratory cut:
Looking toward the catalyst chamber. The perforated pipe dead ends there.
The same two pipes in what I'm calling the intermediate chamber:
This is the catalyst itself - it's actually pretty small.
This is the inlet side of the muffler:
So the exhaust enters through the catalyst into the open cat chamber, then into a pipe which goes into the open chamber of the muffler (bypassing the second chamber) through the pipe on the upper right of the last photo. It then filters through a perforated pipe backward out the port (on the left above) into the intermediate chamber, where it filters into a smaller perforated pipe (seen in the first two photos) which send its 180 degrees back again, not into but through the muffler (lower, smaller diameter pipe above) and direct to the outlet. There is no sound deadening material at all that I could see. I'm not an expert in acoustics or fluid dynamics or, well anything really, but I assume all this is to reduce the velocity and/or pressure as well as to create areas where some wave interference can tune out or dampen certain frequencies (?)
Anyway, all this is just offered as a curiosity mostly. I will probably run my inlet pipe from where the cat used to be and add a section to the body of the muffler to create a chamber where the exhaust can loop back from the inlet tube to the outlet tube. Again, all this is just an experiment; if I like the way it runs and sounds I may leave it (for off road use) and if not I still will have my original, entire unmolested exhaust system that I can swap back on in ten minutes or so.
D) , has a bolt-together exhaust system which allows for individual replacement of the header, the cat, and the twin muffler assembly.
