OzVMX Forum
Clubroom => Tech Talk => Topic started by: Stewart Allen on August 01, 2013, 06:45:28 pm
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Trying to quieten down my CR125M, it has a '76 pipe on it, I cut the end of the pipe (original is welded) & made up a cap so I could repack. Repacked with fibreglass from Torpedo 7, but really not much quieter. Does anyone know if using steel wool or another medium is going to be quieter than fibreglass ?
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One of the few effective ways to make a muffler work better is to make it longer. Its pretty hard to shut up an exhaust if the gases are out the end before the sound energy can be absorbed. Also, don't pack the muffler too tightly.
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I alus uses steel wool.... bad hangover from the 80's and I hate fibreglass. you have to repack a bit more than with fibre glass. if there is a perforated tube, make sure its clean and the holes are clear and can let the sound waves through to the packing.. you can get coarse medium or fine steel wool.
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Trying to quieten down my CR125M, it has a '76 pipe on it, I cut the end of the pipe (original is welded) & made up a cap so I could repack. Repacked with fibreglass from Torpedo 7, but really not much quieter. Does anyone know if using steel wool or another medium is going to be quieter than fibreglass ?
Also dont pack it real tight or it will be noisy.
(my son used to race ktm50s and that was a real difference)
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Who told you that Paul
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Who told you that Paul
:)
(http://i1290.photobucket.com/albums/b525/TFR555/29e10ac241142ece69f6f1b43a39a566_zps520130bd.jpg)
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Who told you that Paul
:)
(http://i1290.photobucket.com/albums/b525/TFR555/29e10ac241142ece69f6f1b43a39a566_zps520130bd.jpg)
Well, that sorted that out! ;)
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Hi All,
Thanks, I may have packed it too tight, I'll try that first & see how it goes. Bit of a worry when you come past the flaggies & they have their fingers in their ears.
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The DEP stringy stuff from ballards is good
About 10 bucks a bag
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A trick I learnt very recently when repacking the muffler on the Team TART RM80 in preparation for the Classic (thanks Foxy) was to "bend" the perforations in the muffler tube so they face into the exhaust gas flow. Along with not packing the muffler too tightly (already mentioned here), I found this to be the best single thing I did to the massive 8 inch muffler. It really worked.
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For the most effective dB reducer is make a end spout that faces the ground, then extending th stinger tube down into the rear cone of the pipe. The sound pressure level is highest at the end of the baffle cone.
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A little video you guys might find interesting
www.boykoracing.com
Hit on : Muffler packing instructions
Quote. " Get this thing as tight as you can get it "
Also google. HONDA CR 500 BY BOYKO RACING
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A trick I learnt very recently when repacking the muffler on the Team TART RM80 in preparation for the Classic (thanks Foxy) was to "bend" the perforations in the muffler tube so they face into the exhaust gas flow. Along with not packing the muffler too tightly (already mentioned here), I found this to be the best single thing I did to the massive 8 inch muffler. It really worked.
I don’t consider that advisable.
Curling the perforations into the flow will only force the exhaust gases into the muffler packing part of the muffler.
As the gases find a way out again they will take a little bit of packing with it eventually blowing all the packing out making the bike louder and giving a drop in performance.
Once the perforated tube is wrapped with packing it simulates a ‘normal’ tube which gives the best performance.
Once the packing starts to disappear the gases find their way into the packing area and out again creating turbulence in the exhaust gases as it tries to leave the muffler, I believe this is why a power drop is experienced and why it is recommended to keep the muffler packed.
I normally wrap my mufflers moderately tight.
You don’t want the packing so loose that the exhaust gases can start to filter through the perforated tube as it starts the process of blowing the packing out.
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Well, that sorted that out ;)
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Things that you should not use as packing.
Asbestos containing products.
Housing insulation fibreglass.
Flyscreens metal or fibre woven.
Your current Manual of Motorcycle sport rulebook.
Steel wool pads with soap.
Tobacco legal or otherwise..
Sushi (upsets the Japanese)
Whale blubber (upsets everyone else 'cept maybe the Norwegians..)
Japanese and Norwegians
Old dry cow dung. Confess to having tried that when much younger ......
Fresh steaming wet cow dung To much of a prick to pack tight in muffler...
C4 plastic explosive Military grade, OK any f*****g grade...
Ya neighbours tomcat that pisses on ya back doorstep! Well yes use the %*&# just try not to get caught..
Ladies sexy lingerie ... The sweet little items melt and stick to the sides ... Um oops how the f**k do I know that!!!!