Muffler silencing
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r97
Measure twice cut once
don't put steel wool near your muffler. i have made a fire with in seconds using a magnifying glass and steel wool
migel101
New member
how is it that no one has simply thought of sticking another muffler in front of the first
how is it that no one has simply thought of sticking another muffler in front of the first
Way too little flow. The current mufflers really choke out the motors as they come.
robbie
New member
Just to be clear, but not beat a dead horse, check out the stainless steel wool you can buy to scrub pots in your kitchen. It's pretty heavy duty stuff, and it won't burn in a muffler. If you use just enough to break up sound waves but not enough to pack the muffler, it would cause a significant decrease in noise. I wouldn't use normal fine steel wool myself.
Doc Sprocket
*********
Y'know, it never would've occurred to me that steel wool could burn. It's steel! I understand that it will glow or whatever when voltage is applied. That's yer basic lightbulb. But burn? Wow. I have some #0000 steel wool I use for cleaning fretboards. I gotta go try something..
EDIT- Well, that was interesting. I smelled something oily as it burnt. I suspect the reason it burns is because it's treated with something to prevent rust. Also, after it went out, I tried to re-ignite it and it didn't work, making me think that once the coating was burnt off, now its just steel... Perhaps you can pack a muffler with this stuff? Maybe put the torch to it before installation to roast off the offending shmegma before it matters?
EDIT- Well, that was interesting. I smelled something oily as it burnt. I suspect the reason it burns is because it's treated with something to prevent rust. Also, after it went out, I tried to re-ignite it and it didn't work, making me think that once the coating was burnt off, now its just steel... Perhaps you can pack a muffler with this stuff? Maybe put the torch to it before installation to roast off the offending shmegma before it matters?
robbie
New member
Super fine steel wool really does burn. It turns into iron oxide.
I'd prefer to use other methods such as dimpled pipe walls, or orienting the inlet pipe into a muffler cylinder on a tangent so as to make the gases swirl. This is a common trick in RC airplane engines, and it seems to work pretty well.
I'm thinking of using both of these features in the same muffler for my next kart. I may get started on it this winter. I'll let you guys know how it turns out.
I'd prefer to use other methods such as dimpled pipe walls, or orienting the inlet pipe into a muffler cylinder on a tangent so as to make the gases swirl. This is a common trick in RC airplane engines, and it seems to work pretty well.
I'm thinking of using both of these features in the same muffler for my next kart. I may get started on it this winter. I'll let you guys know how it turns out.
devino246
Official DIYGK Chem Nerd
I believe its called "coarse steel wool"
Doc Sprocket
*********
"Hello there, Mister local hardware store proprietor dude-guy! I would like to purchase some super heavy duty woven rat's nest steel wool." 
Sorry, man- I had to!
Sorry, man- I had to!
I had no idea if it had a specific name. I was just talking to my grandpa tonight about his time in the navy and he said he had an old pick up on base and his mechanic buddies chopped off his muffler and straight piped it for him and he was threatened by someone of authority cause it was so loud. He told me they stuffed the pipe with heavy duty steel wool and that killed the sound but they could easily pull it out when they got off base. I guys it actually works! As he was talking I just couldn't believe what he was saying cause it was so similar to this.
robbie
New member
Watch out for the word "pack". If you try it you want to allow the gases to flow easily.
If I were to build a muffler with steel wool in it, I'd put a pad of it on one side of the chamber with the inlet across from it on the other side, so the inlet pipe points right at the steel wool. This might break up the sound waves without any obstruction to flow. Imagine a tin can with a pipe coming into the side of the can near the top. Directly opposite is a steel wool pillow, not more than an inch thick. The outlet is at the bottom of the can. That would definitely cut some decibels, but I'm not sure how much. Creating a spiral flow would probably do just as good a job, if not better.
If I were to build a muffler with steel wool in it, I'd put a pad of it on one side of the chamber with the inlet across from it on the other side, so the inlet pipe points right at the steel wool. This might break up the sound waves without any obstruction to flow. Imagine a tin can with a pipe coming into the side of the can near the top. Directly opposite is a steel wool pillow, not more than an inch thick. The outlet is at the bottom of the can. That would definitely cut some decibels, but I'm not sure how much. Creating a spiral flow would probably do just as good a job, if not better.
crazyman
New member
What about stepping the pipe up to 1" then back down to 3/4" with two bushings and a nipple? That should slow the sound waves down some...
(Hi. Newbie.. 1st post.)
(Hi. Newbie.. 1st post.)
devino246
Official DIYGK Chem Nerd
Thats essentially the way the mufflers toystory and I made work. A piece of pipe runs into a larger chamber. The pipe has holes drilled in it and a piece of steel in the middle. This way, exhaust gasses are forced out though the holes, into the larger chamber, and back into the other side of the pipe. Its a very simple concept thats used in nearly all small engine mufflers. The difference is, my muffler is about 5 times the normal size, allowing much better flow and a deeper sound. BTW, welcome to the forums.
robbie
New member
That's how it's done in RC airplane engines. 4 stroke engines have a pipe leading into a cylinder, with a smaller outlet on the end. There's no baffling or packing. They work remarkably well, considering that it's just a pipe and a small cylinder.
2 stroke mufflers are a bit more complex, but not much. They have a bigger chamber with the inlet at a tangent on one end of the cylinder to create a spiral flow, and a small outlet on the other end. Some have baffles in the middle, but even the ones that don't are quite effective.
Using different sizes of pipe is a good idea, but 1" isn't a very big expansion chamber. 3/4" pipe leading to a chamber made from 3" car exhaust with a very short 1/2" outlet would work better.
You guys really have me going now. I need to build one of these just to see how quiet I can make it, with the least back pressure.
r97
Measure twice cut once
be kinda cool if someone could figure out a way to do this on a kart, lol.
http://www.youtube.com/watch?v=XoB2zhgcQqY&feature=related
http://www.youtube.com/watch?v=XoB2zhgcQqY&feature=related
Doc Sprocket
*********
Please do. I think it would be very beneficial for our brothers in residential-type areas to have a solid designed plan for a hi-po quiet muffler that's feasible for Joe Fabguy to toss together...
Do you have a means of measuring sound levels in order to gauge your progress? Perhaps look around for a low-priced decibel meter?
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