Quiet muffler

[Smally]

I'm in the assembly stage on my Super Bronc. What are my options to obtain the quietest sounds coming out of my HM100. I don't want folks hearing me coming from two blocks away. Think stealth. Thanks.

 

[jeep2003]

Generator mufflers are the quietest youll find but they are usually pretty big. I put a hotdog muffler after the stock muffler on mine. its quiet but probably restictive

 

[MolonLabe420]

So what is everyone's thoughts on the best way to make a performance exhaust quiet?
I'm thinking you would have to adapt a car's cat or something... like from a Honda or even a Geo Metro maybe... big enough to flow a single cyl, but restrictive enough to muffle the noise....

 

[joebiodiesel]

Try a stock Predator one. So many folks take them off to put headers on, I'm sure you could get one for a song. They're even cheap if you had to buy a new one.

Joe

 

[MJL]

Aside from the muffler, keep the RPMs down, and easy on the throttle. Setup your clutch or TAV for lower engagement RPMs with light springs. You'll lose performance, but if stealth is your goal...

 

[TheDullCarbide]

Are you looking for bolt-on, jerry-rig, or home-made?

 

[Smally]

Looks like I have bigger issues. My carb installs straight off head. Former owner had straight 3/4 npt header that just touched the air cleaner housing. No muffler will clear the air cleaner. When looking at the Heald build drawing, they show a short muffler that angles away from the flange, thus clearing the air filter. I have never seen this available. So, I will have to buy the intake manifold that drops the carb off the engine and turns is 90 degrees. I have the pulse fuel pump that I just rebuilt. Since the carb is now dropped lower, I guess I do not require the fuel pump anymore? Thoughts? Does anyone out there fab custom headers that have a 3/4 NPT female end on?

 

[FOMOGO]

Use a 3/4 pipe thread street elbow that has a 45 degree angle to turn the muffler away from the carb. Lowes or Home Depot has them on the shelf.

 

[Smally]

Sometimes the best ideas are right in front of us. Thanks FOMOGO.

 

[Harquebus]

...Does anyone out there fab custom headers that have a 3/4 NPT female end on?

The 45° 3/4" elbows are definitely what I went for. Less restriction, you know.

There's a seller on fleabay making all manner of Honda/Predator/Clone headers or exhaust pipes and he was willing to accommodate me by adding a 3/4" NPT coupler on any style he makes for a sausage muffler.

I think he might be inclined to go "all custom" if we were to plant the seed in his ear... JTW Fabrication...

https://www.ebay.com/usr/jtwfabrication?_trksid=p2047675.l2559

 

[lostinbaja]

I made one that looked like an OE Nelson muffler, from a John Deere lawn tractor Nelson muffler. This is what I started with:

 

[MolonLabe420]

How well does that John Deere muffler breathe?

 

[lostinbaja]

It's a Nelson muffler and it came off a 10hp Kohler and looks almost like the OEM Nelson muffler that Heald sold for their bikes and it works great on my bike. You tell me?

 

[Smally]

Great idea. Let me shake the bushes. I'll report back. Thanks.

 

[miniminibike]

https://www.oldminibikes.com/forum/mini-bike-discussion/138633-home-super-bronc-muffler.html

 

[ruppmanbob]

just surfing around for a while today. Finally rode my 70 Enduro with a predator 212 the other day. wheelie machine.

 

[65ShelbyClone]

Eh, wrong thread?

So what is everyone's thoughts on the best way to make a performance exhaust quiet?

Assuming that spark arresting is not needed, a long perforated-core muffler usually offers the best compromise between flow and sound attenuation. Quiet doesn't have to be restrictive.

Looks like I have bigger issues. My carb installs straight off head. Former owner had straight 3/4 npt header that just touched the air cleaner housing. No muffler will clear the air cleaner. When looking at the Heald build drawing, they show a short muffler that angles away from the flange, thus clearing the air filter. I have never seen this available. So, I will have to buy the intake manifold that drops the carb off the engine and turns is 90 degrees. I have the pulse fuel pump that I just rebuilt. Since the carb is now dropped lower, I guess I do not require the fuel pump anymore? Thoughts? Does anyone out there fab custom headers that have a 3/4 NPT female end on?

If at all possible, I would recommend using a bolt-on flange if you hang a pipe and muffler off of the block. If the pipe has any play at all in the block, it will eventually pull the threads out.