Gut Factory Muffler

[Offroad]

Is it this easy? or is that baffle attached on the inside?
https://www.youtube.com/watch?v=5Nr62-8nHuU
Or does the inside look like this? See frame 0:38 seconds in...that would be a nightmare!



https://www.youtube.com/watch?feature=pl...H-9V6sg3Zc

[Tortuga_imp]

Offroad,

I think Red Mist touched on the resonator aspects of mufflers a little bit somewhere on here. As a racer he seems pretty familiar with backpressure, cyl. scavageing, and all that. I think Red Mist might be Kevin Cameron...

Everyone here knows that Red Mist is Freddie Spencer.

[Offroad]

OK, I know this is kind of a hack job, but I bought a used muffler to experiment on.
I've learned some things....the baffle is attached BOTH at the front and down inside the muffler.
[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100/pipeshortened2_zps5ca1fc64.jpg.html]
[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100/holesawcutcompleted2_zpsfe48c9d4.jpg.html]
[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100/vcutsshown2_zps3569f0d9.jpg.html]
[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100/showinginterierpipes2_zps53f167b8.jpg.html]
[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100/halfcutaway2_zps5d738302.jpg.html]

[CB4ME_imp]

Blazing the trail. Thanks for the pictures!!

[mininsx_imp]

Now all we need is a sound clip!

[Offroad]

I tried to get a sound clip with my phone, but it doesn't do it justice....maybe I'll try my little digital camera.

[Offroad]

I updated my cut away on the factory muffler...I know it's a "hack job", I'm no professional and only have common tools to work with, but I plan to either cover it back up with the bezel get a real machinist to smooth it up some more.

To get rid of that center pipe, I'm thinking I need an inside pipe cutter, but most I've seen are for PVC, I need a metal one about 5-6 inches deep. Any suggestions?

The cutters I've found are so expensive I thought about seeking out a plumber to cut it for me.

My main problem is IT SOUNDS SO GOOD, I DON'T WANT TO PUT THE CAP BACK ON! I think there is something about the "megaphone" design that a cap just ruins. And I LOVE THE BACK FIRING, I don't know why, I just do.

So I'm toying with the thought of cutting the cap mounting tabs off, cutting that center pipe back and I would almost have that uncapped 4-1 Kerker header on the Kawasaki Z1 900 I keep remembering as being the sweetest sound I've ever heard out of any motorcycle. I'm thinking with the tabs off, the pipe will soot back up quickly, and most will only see a flat black hole?

Or on that primary input pipe, daylight can be seen when the muffler is off. With the muffler off you can see there is another perforated baffle that could be cut way from the front of the muffler. Maybe then I will be satisfied with the sound with the cap back on.

Bottom line, I know it looks bad, but it sounds good, so I'm following the Engineering Creed - Function over Form ;-)

PS: I'm only doing this because I bought this used to experiment on, I have my original muffler safely packed away in case I ever need it.

http://www.esm.psu.edu/courses/emch13/de...rocess.pdf

[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100%20Muffler%20Cut%20Away%201a_zpsndy8phxt.jpg.html]

[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100%20Muffler%20Cut%20Away_zpsyx2btmbs.jpg.html]

[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100%20Muffler%20Cut%20Away%201_zpsydyvtvzg.jpg.html]

[url=http://s1280.photobucket.com/user/offroadfx4/media/CB1100%20Muffler%20Cut%20Away%202_zpstk9ejuri.jpg.html]

[ChipBeck_imp]

Gentlemen,

The exhaust passing through the standard CB11 muffler makes two complete changes in direction. The inside of that muffler looks like this.

[url=http://s288.photobucket.com/user/chipbeck/media/Mobile%20Uploads/image.jpg.html]

Cheers.

Chip

[mininsx_imp]

I was looking at this yesterday and I was wondering if a few small "louvers" cut just inside the exhaust pipe would make it a bit louder. A cutting stone on a Dremel might do the trick. And no, I haven't tried it yet.

[Offroad]

The center pipe is relatively soft thin metal, I did shorten mine with a dremel...the problem is getting a long enough shaft to reach deep enough to get past that big baffle plate.

I'm assuming they don't make an extra long dremel cutter because it can't take the side loads, at least if they do I haven't seen one.

If I could get a dremel cutter 5 inches long, I could shorten the center pipe now, since nothing is flowing through it, it's kind of useless.

I have wondered about cutting the bezel hole bigger, but I need it to be a very clean even cut since it will be exposed....any suggestions on how to cut it?

I thought about grinding along a ridge, what I think really need is a big fancy laser cutter?