Building mufflers.

[Basement rat]

I might try it this winter. I have various metals as well as mild steel and aluminum, Ti, a shear, notcher, sheet metal roller, tig welder and other crap.

I have the tools and metals, but how do you build one?

 

[jay_kent]

When I put my headers back on my bike I thought that a shorter muffler would do the biz perfectly rather than the longer one. I've got nothing for you but I'd like to know the info as well.

Jay

 

[DrJ]

There's a guy in Toronto that makes custom mufflers. I've seen his work and it's excellent. He starts with flat sheets and rolls them into cylinders and welds the seam.

 

[Basement rat]

That makes a tube well enough, what about the insides?

 

[DrJ]

You can buy baffles, fill with packing and mount with a couple of bolts.

 

[Bobdot]

Couple of sites I've collected:

http://niskygarage.logical.net/CB350/project_cb350.html - Scroll down and click on anything with "exhaust" in the description (weeks 11-14b)

http://www.theflyingbanana.com/mufflers.htm

Hope that helps

bob.

 

[dielectric]

Hydroforming gets you a really pretty, sweeping exhaust:

http://www.eurospares.com/frame8.htm

 

[Bobdot]

^^^^ Holy crap thats cool.

 

[JRK5892]

i made my own for my TX500, just welded some flaired pipe on and dropped in some baffels from a harley set of pipes i had... took a bit of work but they sound wicked

i have also seen them made from cocktail shakers

 

[Basement rat]

Perfect!

I might be building four this winter...

 

[derant]

Download the Cone Layout software from http://pulserate.com and use it to create and create the flat patterns to transfer to your sheetmetal.

You have a ring roller, so forming the cone isn't an issue.
If you don't have a ring roller you can use a rubber mallet and a long enough length of pipe to accomlish the same thing.

Lay your sheetmetal blank across the pipe and use the mallet to hammer down the length of it. Move the sheetmetal over on the pipe a bit and repeat the hammer process. Done enough times, the sheetmetal will start to roll forming a cone.

This picture illustrates the process some.

 

[Basement rat]

Tooling aint a problem at all, but that would work for anyone without!

I'm up in the air right now if I want to use titanium or carbon fiber. If I go the CF rout, I will make a mold from some wood (probably a 4x4) and run it on a lathe with a taper attachment until I'm happy with my shape, seal it, wax it, make my lay ups and I have my shell. The inside would be easy now too since I know what it looks like.

I don't need any software to tell me what to cut out to make my template, I will just use some card board, roll it until I'm happy with the taper, mark it, cut it and I have a template.

This wont happen for a few months but its good to have the time to think it through before I start.

 

[teazer]

Or just buy some C/F tube in an appropriate size. When I had to rebuild a Yoshi muffler a couple of years back I found a metal store on line called something like online metals dot com and located a suitable aluminum tube and they cut me a piece exactly the right size. All I had to do was drill each end to fit on teh end caps and polish it.

Perforated cores are available off the shelf too if you search. All you need to make are the end caps

If you want to make megaphone or Gold Star shapes, that's a little more work and you can but cones from a couple of places on line. Aircone used to the the place. No idea if they are still around though. Or roll them yourself with a set of slip rolls. Then you'll want to dyno test and noise test them so that when the noise police bang on your door, you'll have the documentation you need.