How to Quiet a 50cc Gasser? Help!
09-12-2010, 05:05 PM
#26
RE: How to Quiet a 50cc Gasser? Help!
Success!
I have been successful in reducing the noise level of my engine from 104db to 97db by inserting baffling material into the muffler. Thanks to all those who offered advice. Hopefully others can benefit from my experience.
In the first picture, you will see the two different types of materials I used purchased from a local hardware store: 1) steel scouring pad material and 2) lint trap material.
Putting scouring pad material into the main chamber of the pitts muffler reduced the noise by about 3db. As pointed out by one of the posters, it has to be held in by something or it will eventually blow out. Putting a small roll of lint trap material into each of the two exhaust pipes reduced the noise by about 2db, but with less of a performance penalty. Using both the steel scouring pad material and the lint trap material, I was able to reduce the noise level to 95db. That’s a 9db decrease! But, the performance penalty was about 900 rpm. By removing some of the scouring pad material, I was able to reduce the noise level to about 97 to 97.5 db, just under the 98db limit, with a performance penalty of 300db. So, it’s just a matter of finding out how much material is needed to obtain a particular noise level, recognizing that the more material is used, the worse the performance.
After the engine breaks in a little more I may try a Menz S 21x12 or perhaps a 22x10. In my situation prop noise was not really the issue. The tone or "bark" of the engine could be heard even at low rpm and was very apparent in the mid range.
-Ed B.
I have been successful in reducing the noise level of my engine from 104db to 97db by inserting baffling material into the muffler. Thanks to all those who offered advice. Hopefully others can benefit from my experience.
In the first picture, you will see the two different types of materials I used purchased from a local hardware store: 1) steel scouring pad material and 2) lint trap material.
Putting scouring pad material into the main chamber of the pitts muffler reduced the noise by about 3db. As pointed out by one of the posters, it has to be held in by something or it will eventually blow out. Putting a small roll of lint trap material into each of the two exhaust pipes reduced the noise by about 2db, but with less of a performance penalty. Using both the steel scouring pad material and the lint trap material, I was able to reduce the noise level to 95db. That’s a 9db decrease! But, the performance penalty was about 900 rpm. By removing some of the scouring pad material, I was able to reduce the noise level to about 97 to 97.5 db, just under the 98db limit, with a performance penalty of 300db. So, it’s just a matter of finding out how much material is needed to obtain a particular noise level, recognizing that the more material is used, the worse the performance.
After the engine breaks in a little more I may try a Menz S 21x12 or perhaps a 22x10. In my situation prop noise was not really the issue. The tone or "bark" of the engine could be heard even at low rpm and was very apparent in the mid range.
-Ed B.
