Topic: Exhaust fiberglass?

[brett_bike]

I currently have a Mac 4 into 1 exhaust on my '73 CB500 and (like many others) I don't much care for the tin can sound.  I was wondering if anyone has ever done any sort of fiberglass wrap around the baffles and what sort of complications this may cause.  I want the bike to have more of a deep roar than a hollow tin can sound.  Also, does back pressure come into play with this sort of modification?  Any thoughts?

[Don R]

I wrapped the baffle on mine with some pink owens corning from Lowes, they sell a small roll for a few dollars. Toned it right down, I like it. Runs fine but don't get it over the end of the pipe and plug it like my bikes PO did.

[Steve F]

Go to the dollar store and get some of the small stainless steel scouring pads. They are round with a hole in the middle. Pack them onto your baffle...the tighter the more baffling the noise. Will never blow out. Lasts forever.
Steve

That's a cool idea......

[brett_bike]

Thanks Don R and Swoop, those are both cool ideas.  I think I will check out the dollar store idea today after I figure out how to remove my baffle from the Mac.

[Gordon]

Go to the dollar store and get some of the small stainless steel scouring pads. They are round with a hole in the middle. Pack them onto your baffle...the tighter the more baffling the noise. Will never blow out. Lasts forever.
Steve

I tried that once on my CB360.  After one decent ride the steel wool had almost completely burned away. 

[the technological J]

i have used the steel wool remidey also with no luck and want to use fiberglass but didnt know if any fiberglass is acceptable or if theres special stuff.... i have also heard bad things about steelwool

[Haoleman]

regular steel wool will burn up/rust and rot. Brillo pads (the course ones ) or better known as grill scrubbing pads available at restaurant supply stores that are made out of stainless steel should work fine.  Try em and let us know the results.  I guess it's the particular sound that is appealing.  Like in cars, I like the sound of Borla (has sort of a tinny sound vs the crap sound of a Cherry Bomb which does like they say in their ad "disturb the peace".

[Gordon]

I bought a small roll of yellow fiberglass insulation at Home Depot and wrapped it around the baffles with some steel wire and it held up well.  

[HawaiiMike]

The regular pink fiberglass works fine.  I used to use that in my RD400's.  Much cheaper than buying fiberglass packing from a motorcycle parts shop.

[brett_bike]

Well, never made it to the dollar store today.  I had to go to my bike shop and build some wheels for a customer.  I guess that's not a bad thing by the sounds of Haolman's post.

HawaiiMike, how much of the pink fiberglass did you use?  How tightly did you pack/wrap your baffle?

Thanks again for all the idea's fellas.

[Don R]

I just wrapped it around twice and spiraled some duct wire around it. Twisted the ends good to go. Got a couple hundred miles so far. No change.

[KB02]

If you've got a MAC exhaust, check out this thread:
http://forums.sohc4.net/index.php?topic=32177.0

[brett_bike]

Thanks KB02

That gives me an idea.  I may pull the baffle out, take some measurements,  and try to weld something up to press back in place.  Something like a stainless pipe with multiple holes drilled into it, then weld two outer plates that will press into the can like the original baffle.

[KB02]

You can also check out this site for parts.   
http://www.coneeng.com/mufflers.html

[Kframe]

i have used the steel wool remidey also with no luck and want to use fiberglass but didnt know if any fiberglass is acceptable or if theres special stuff.... i have also heard bad things about steelwool

No, use this stuff:
Stainless steel scouring pad


Not this:
Carbon steel wool


-K

[HawaiiMike]

HawaiiMike, how much of the pink fiberglass did you use?  How tightly did you pack/wrap your baffle?

Thanks again for all the idea's fellas.

I just had a couple of feet, you don't need much.  I packed it pretty tightly and then used masking tape to hold the fiberglass in place as it was inserted back into the muffler.  By the way, I once tried steel wool too and it blew out very quickly.  The stainless steel scouring pads look like a great idea!

[coneeng]

You can also check out this site for parts.   
http://www.coneeng.com/mufflers.html

Try stainless steel wool, 3/8" thickness.  Wrap it around your baffle once with a little overlap.  It can be spotwelded in place or a home remedy is to take SS MIG wire tightly wrap it around the steel wool and tack it on the ends. 

Steel wool won't absorb sound but it will absorb sound but it does lower the tone and takes out the tinny sound mentioned earlier.  Fiberglass home insulation has a low temp melting point and will get solid and hard quickly which will make the pipe louder by not allowing the exhaust pulse to expand out of the baffle and into the muffler body.

[ColinMc]

I went to my local motorcycle shop and bought fiberglass meant for repacking mufflers. Works great and is meant for it. I think Moose made it?! It was for dirt bike mufflers.