Bonneville America Forums Forums Technical Forums Exhaust How to make thunderbike's quieter according to....

What he is saying is that your exhaust sound waves are not able to diffuse into enough of the packing material to quiet the sound effitiently. In order to let more exhaust reach the packing material you have to drill more holes(perforations) to let more of the exhaust sound waves escape into the packing material.....Be sure to wrap the newly drilled holes with packing material.......Angelis