Rear Exhaust Noise Levels

[mrstaffo]

Hi everyone,

I have a VXR with a RIVA rear exhaust kit and it is quite loud. While I love the performance gains and badass sound, I worry that I may be over the legal limit as far as noise levels. The law here in Michigan states your boat should be no louder than 90 decibels at idle from 3 ft away and 5 ft above (or something like that) and no louder than 75 decibels measured from the shore (or 50 ft away). The latter is a little vague--is that measurement also taken while idle? I'm not sure. Anyway, I just so happen to have a sound meter, so I did a test at close range with my ski out of the water and got a rating of 88 decibels. I'm assuming in the water it would be even quieter. So, according to that test I'm good with a little bit of cushion. Has anyone ever been slapped with a noise citation for their exhaust kits? Do you know of any removable baffles that would be compatible with the RIVA exhaust kits? Just something to take the edge off maybe. Or am I stressing too much? lol I'm sure there are power boats out there with much louder exhausts stock. Any input would be much appreciated!

[mrstaffo]

And actually, I'm reading now that the Michigan law enforcement officials uses the dB(A) scale and not the dB(C) scale when taking sound meter measurements. The dB(C) scale is for lower frequencies, which is what I used to measure my exhaust noise. I don't recall the exact measurement I got for dB(A), but it was at least 10 decibels lower than the dB(C) measurement. In that case, I should be good.

[Tiny]

The noise levels for the 50 feet away is taken at WFO and someone on the beach or dock pointing a decibel meter at the back of your ski.

The IJSBA use to make a big deal of this back in the old days of the loud triple pipe GRP's, they could be stupid loud!!!! Guys were mounting pieces of rubber off the backs of their skis to deflect the noise to the sides instead of out the back for this....LOL!!!

[mjh3ides]

The rear exhaust on my SHO was a little too noisy for me, so I installed one of these resonators in it. It didn't quiet it down a whole lot but made it more bearable. Most noticeable was it gave it a deeper exhaust note & got rid of the raspy sound it had before. Simple install...cut a section out of the Riva tube & install this with some silicone couplers & clamps. If you're close to the legal limit, & it's enforced, this might quiet it down just enough to give you a little cushion.

http://www.amazon.com/Vibrant-1796-S...s=vibrant+1796