Help with passing Noise restricted areas.

[spl170_btc]

Hello,
Anyone out there know any tips, and tricks on how to pass noise restricted riding areas? I ride a 99 CR250 with FMF pipe and silencer. Packing the silencer should help some but the dB limit is at about 94 in Florence OR I think and that is way to low for 2 wheel 2 strokes. Any advice or tricks would be greatly appreciated.

Thank you

 

[David Trustrum]

Sorry but the news is not great.

The std pipe will be quieter. Thin pipes ring along their entire length. The noise is created by the sound pressure wave created when the exhaust port is first opened.

The wave energy is constant but the pressure diminishes as it travels into the larger dwell section of the pipe. Unfortunately it increases again as it travels into the thin stinger. Funny as it sounds you can block up the baffle cone & reposition the stinger to the larger dwell area. This will quieten the outlet noise substantially. This is not a new idea.

Sadly the thin after-market pipe will still ring.

In the real world make sure you run any airbox lid or funnels fitted std as the intake noise can be substantial. A decent muffler which has a couple of reversals will be quieter. Repack the muffler regularly. Use a decent packing like Daytona or similar.