Saw this on You Tube...home made Flowmaster...
https://youtu.be/svtrd_PzaEo
https://youtu.be/svtrd_PzaEo
Building a quiet muffler...
- Thread starter gumpit
- Start date
- Tags building muffler... quiet
I'm about to make a custom exhaust for my Rupp because it's got a Honda GC160 swapped in and has a functional but junky setup. Being a V8 car guy, I also was thinking about making a small scale version of a flowmaster as well as trying to keep volume down to avoid being a nuisance. Not sure how loud it would be with a standard chambered design without any packing. I thought it would be hilarious though.
There's plenty of room under mine to stick something rectangular but maybe not so much on the small wheel bikes. It should be pretty stinking easy to make. I picked up one of those cheap 8hp 3/4 npt Briggs style cans to possibly use but I don't like the look and was thinking of welding a stainless tip around it. I had thoughts about dual tips with one coming out either side under the frame but haven't decided anything for sure yet. I thought that maybe running dual briggs cans could also result in reduction in volume without restricting
There's plenty of room under mine to stick something rectangular but maybe not so much on the small wheel bikes. It should be pretty stinking easy to make. I picked up one of those cheap 8hp 3/4 npt Briggs style cans to possibly use but I don't like the look and was thinking of welding a stainless tip around it. I had thoughts about dual tips with one coming out either side under the frame but haven't decided anything for sure yet. I thought that maybe running dual briggs cans could also result in reduction in volume without restricting
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The intake can make as much noise as the exhaust because it pulses also. Fortunately you can make an intake muffler (airbox) out of plastic so fabrication is easier. With both intake and exhaust you are trying to slow down the pulse without restricting the flow, especially at high RPM's.
I have made muffler cores out of electrical conduit by pinching the end shut for the engine side and then drilling a bunch of small holes in the pipe. It then slides in through the muffler outlet hole and gets a screw to hold it into place. They are not at all restrictive at lower RPM's.
I have made muffler cores out of electrical conduit by pinching the end shut for the engine side and then drilling a bunch of small holes in the pipe. It then slides in through the muffler outlet hole and gets a screw to hold it into place. They are not at all restrictive at lower RPM's.
Watched that home made flowmaster video and it doesn't look like it's very quiet from what I could tell and it was pretty large. That's kind of what I was worried would be the result. So far the best SOUND improvement I saw on YouTube was like a 4" fire extinguisher body that lowered the tone a bit. That ends up eating a lot of space though. Made it sound less like a lawn mower though which I like
if you have the room on your bike? i have seen two different style mufflers that are very quiet. nelson round muffler on a super bronc and the flat spark arrestor muffler on a super bronc. i believe markG was telling me this summer he could notes the difference in power from flat style spark arrestor to a standard thread on unversal thread on muffler. so there could be some loss power when getting into the quiet mufflers,but not all.
here is something i have done in the pass if a person does not have the room for a muffler,but still wants his bike to be little quiter then straight pipe.
took some washers and split them up into a curly Q)))) use a bolt for my jeg.......:thumbsup: you can tig it together or wire feed it together.
place it into your pipe
drill couple holes in your pipe where you want it and weld it in.
grind the weld down and your finish.
you can see on this bike there is no real good place for a muffler and on this bike it would probably not look good with a big muffler hanging on it..:doah:
i find that the thick over size washers work the best to make a header flange. just lightly grind off the plating before welding.
finish bike the pipe was put on.
here is something i have done in the pass if a person does not have the room for a muffler,but still wants his bike to be little quiter then straight pipe.
took some washers and split them up into a curly Q)))) use a bolt for my jeg.......:thumbsup: you can tig it together or wire feed it together.
place it into your pipe
drill couple holes in your pipe where you want it and weld it in.
grind the weld down and your finish.
you can see on this bike there is no real good place for a muffler and on this bike it would probably not look good with a big muffler hanging on it..:doah:
i find that the thick over size washers work the best to make a header flange. just lightly grind off the plating before welding.
finish bike the pipe was put on.
danford1
sorry i don't, for my application it keeps the noise down on a stock 5hp motor. not sure how well it would keep the noise down on a built high compression clone engine.......:shrug:
that also may depend on how long you make your baffle and how long your pipe will be and if it has any bends in it....
that also may depend on how long you make your baffle and how long your pipe will be and if it has any bends in it....
over the winter months i would like to build a muffler something like a nelson muffler that came on the super bronc's , but make it more rounded on the ends. going to use some of my dies from my gas tanks i make and also make some new dies and create a new muffler and also design the insides like a flow master muffler. so it is non-restrictive.
one of the steps i will leave out would be the concave for the filler neck and i would use a smaller material to make the muffler out off. i would use a 3 inch round material. pictures posted here are made out off 3.5 inch material
here is something how the exhaust ends would look without the concave. muffler ends would come straight out.
everything would have to be tig welded and not solder welded like my tanks are.
one of the steps i will leave out would be the concave for the filler neck and i would use a smaller material to make the muffler out off. i would use a 3 inch round material. pictures posted here are made out off 3.5 inch material
here is something how the exhaust ends would look without the concave. muffler ends would come straight out.
everything would have to be tig welded and not solder welded like my tanks are.
Here are a few pictures of my home made super bronc vt8-12 muffler. I made it out of 3 inch exhaust tubing and 3/4 inch tubing for the inlet and exit pipes. I cut out and welded 2 discs into the inside of the exhaust tubing with holes drilled randomly throughout to equal the volume of the 3/4 inlet pipe.. I then shaped 2 ends and welded in place.. The exhaust is quieter than the engine except at wide open throttle. It is slightly smaller in diameter than the Nelson muffler but it is the same length. Took about 2 hours to build.
