Suggestions on making a muffler. Design, materials, fasteners

[ShaggyZ]

I might make one for my Z, but I've actually started this thread because I fully intend to build dual mufflers for my motorcycle, a 2003 Suzuki SV650. Mufflers for motorcycles typically cost $300+ and I'm not interested in spending that; there is a really cheap muffler that recently appeared for the SV650, Delkevic, that is only $150 shipped. Still, I'm shooting for an undertail, dual exhaust.

 

The outer cans of many motorcycle mufflers are aluminum but I don't know about the inner, perforated pipe. The design I'm going for is a straight-thru type with a perforated (probably just drilled) pipe surrounded by steel wool; the space between the outside of the inner pipe and the inside of the outer piece will likely be .5"-1.0" and the steel wool will fill that gap. The outer diameter of the outside pipe will be 3"-4", but hopefully 3" will provide enough packing material to provide a good tone.

 

The mufflers will each probably have 1.75"-2" inner diameter and a length of 18", not including whatever type of tip I may include. They will run the length of most of the tail and will be within a couple inches of the tail plastic so I'm going for as little heat radiation as possible; I'd like to avoid additional heat shielding or exhaust wrap. Carbon fiber would be an ideal muffler material for this but it's not an option.

 

Really, I would be okay with some thin sheet metal that can handle the heat well enough, which will be just about any metal. The inner pipe can be thin steel tubing. I'm not sure what type of steel wool is best or if I should consider another readily available material.

 

Ultimately, I don't have to make the perfect muffler because I'm kinda thinking this will be just a prototype from which I'll learn some lessons. Keep in mind these mufflers are totally exposed so they need to be somewhat aesthetically pleasing, as opposed to most car mufflers.

 

I don't mind being directed to another thread I didn't find or a website on muffler making.

[turborust]

Instead of steel wool I would go with fiberglass mat used for rebuilding mufflers, and its cheap.

 

http://www.amazon.com/Moose-Racing-Fiberglass-Muffler-Packing/dp/B001DDBK7U

 

As far a making a muffler I think the biggest obstacle will be the end caps. The side that will connect to the exhaust manifold, a transition with whatever style exhaust flange would be an easy option. Or if you can find some thing off another muffler with similar dimensions that you are after and use it for the end caps.

 

http://www.mandrel-bends.com/catalog/transitions-forms-45/transition-cones-63/1-75-to-2-00-transition-cone-696.html

http://www.burnsstainless.com/cgi-bin/order.py?action=add&part_number=RD-138-200-16-MS-S

http://www.mandrel-bends.com/catalog/flanges-v-bands-36/universal-exhaust-flanges-52/2-25-mild-2-bolt-universal-exhaust-flange-1001.html

 

And a easy way to secure whatever you come up with for the end caps would be rivets that you can drill out for repacking.

 

Appearance will depend on what you can afford. Hi temp manifold spray paint or Hi temp powered coating depends on what is left of your budget.

[dan5138]

+1 on not using steel wool. This stuff catches fire pretty darn easily.