Exhaust sound testing

[sunsationdave]

Hello Codeman671
Back in 2001 I had to take a drive by test the mp were 50 ft away
Had to pass 2 times . I was 80 decables 82 was the limit . when the mp first caught me I had no mufflers on a single 496mag ho . they gave me 7 days
to take the test .I put mufflers on and passed at 80dbl one mp was in my boat and the other one was in the mp boat 50ft away. this is what they did to my friend last year .
my 2 sunsations
288 and/32ss both had mufflers and never had a problems with the mp
my new formula 310ss has 2/ 496mags with mufflers and captians call exhaust
it is below 82 either way.It was passed this year switchable exhaust as long as it is under 82 on newer boats. last weekend I noticed a GF boat at your dock. Yep thats me flying by with the blue 310ss formula hitting the air horn
anyways good luck with the GF boat . if the speed limit goes away I will have a new 36SSR with 700s

[BroadHopper]

MP thought my Liberator 211 was loud. I had an appointment over by Timber Island for testing. One MP was in the boat with me. Another in an p-boat. They would take measurement at idle. Then I made a pass and a return pass at full throttle while being measured. Since I had an 1985, I has 2 decibel below the maximum. The law then was to measure at full throttle.

My grandfather/father's old vintage boat is wicked loud. No mufflers. They were never pulled over.

[Skip]

Saf-C 403.23 Noise Level Testing Procedure.



(a) This section shall set forth the procedure to be used to measure marine engine noise levels, pursuant to RSA 270:36-40.



(b) The following instruments shall be used to measure decibel levels of marine engines and motors:



(1) A precision sound level meter that conforms to the specifications of ANSI S1.4-1983; and



(2) An external field test, such as a sound level calibrator.



(c) The test site shall be located in a calm body of water that is large enough to allow full speed pass-bys, as designated by the division.



(d) The area around the test site, for a minimum distance of 100 feet, shall be free of large obstructions, such as buildings, boats, hills, large piers, and breakwater walls.



(e) The test course shall consist of 3 small buoys, in a straight line.



(f) The test boat shall be positioned parallel to the test course, at a distance of 50 feet from the center buoy of the course. The bow and stern of a test boat shall be secured to moorings.



(g) There shall be a marine patrol officer on board each boat tested. The marine patrol officer shall stay on board each boat tested to verify that the boat was operated at maximum speed, pursuant to (k) below, for 2 of the pass-bys, during the noise level test.



(h) Calibration shall be as follows:



(1) The sound level meter used for the purpose of making measurements under this section shall be calibrated using an external field test;



(2) Field calibration of the sound level meter shall be made immediately before and after each test sequence;



(3) A notation of successful completion of the field calibration shall be made, by the person performing the calibration, on a noise test report form;



(4) An external standard calibration test shall be conducted annually on the sound level meter, and the external field test; and



(5) A copy of the external calibration test forms, filled out by the person(s) who performed the last external standard calibration, shall be evidence that the sound level meter and external field test were properly calibrated at the time of the noise level test.



(i) The ambient sound level, including wind effects, due to noise sources other than the vessel being tested, shall be measured immediately prior to the test sequence of the vessel to be tested. The value shall be recorded.



(j) The temperature, humidity, and windspeed shall be recorded. They shall be the current values available and reported by the National Weather Service at the nearest observation station to the site.



(k) The test shall consist of 4 passes along the test course of 3 buoys, at a distance of 1 to 3 feet from the buoys. The direction of travel shall be reversed between each run. The first 2 runs shall be at the boat's half throttle cruising speed, and the other 2 runs shall be at full throttle.



(l) During each test, all radio equipment shall be switched off. An officer shall hold the sound level meter 5 to 6 feet above the water with the microphone inclined approximately 70 degrees off horizontal, facing the center buoy of the test course. The results of each run shall be recorded by a marine patrol officer in the test boat.



(m) Each meter reading shall be obtained as the boat is within the boundaries of the test course, at the highest sound level for each speed.



(n) All values for (m) above shall be recorded, however, the sound level shall be the average of the 2 readings, rounded down to the nearest whole number.



(o) The officers conducting the noise level tests shall maintain a log sheet that records the following information:



(1) Name and address of owner of the boat;



(2) Date of birth of boat owner;



(3) The document that the officer checked for proof of identification of the boat operator;



(4) Names of officers conducting the test;



(5) Date and time of test;



(6) Location of test site;



(7) Weather conditions;



(8) Water conditions;



(9) Color of the boat being tested;



(10) Make and model number of boat being tested;



(11) Length of boat;



(12) Boat registration number;



(13) Hull number;



(14) Names or distinguishing marking on the boat;



(15) The result of the field test of the sound level meter;



(16) Direction of the test pass, either left or right; and



(17) Results of each test.

[tis]

Originally Posted by BroadHopper

MP thought my Liberator 211 was loud. I had an appointment over by Timber Island for testing. One MP was in the boat with me. Another in an p-boat. They would take measurement at idle. Then I made a pass and a return pass at full throttle while being measured. Since I had an 1985, I has 2 decibel below the maximum. The law then was to measure at full throttle.

My grandfather/father's old vintage boat is wicked loud. No mufflers. They were never pulled over.

Someone had said it has changed but that is the way it used to be. You get stopped, they "invite" you to go to Timber Island. The boat is not allowed to be used until the test is taken. THe MP boat is moored close to the island and one MP goes with the driver to make the passes. If you aren't less than the 82 decibels, then again you are not allowed to use your boat. You are allowed to go to the marina for the work. THe marina said we would pass the first time, but we didn't. Nor the second. I can't remember but it was three or four times before we finally got it quiet enough. And a lot of money too.

[Paugus Bay Resident]

I had to go through the Timber Island drill a few years ago with a 33 Baja with HP500s and stock exhaust. Failed the first test at 84. Schedule the second test for a week later, but MP cancelled it due to fog and its effects on measurements. Still can't use the boat. Final test (and I'm not condoning this ), I stuffed my tips with steel wool. Had to do 3 passes. First was at 78, second was at 80 and third was at 84. Average 82 and a pass. Voila, no more steel wool, or should I say evidence. Only risk is creating too much back pressure, so it took a little trial and error.

BTW, saw your post on OSO. Great boat, great deal.

[tis]

Originally Posted by Paugus Bay Resident

I had to go through the Timber Island drill a few years ago with a 33 Baja with HP500s and stock exhaust. Failed the first test at 84. Schedule the second test for a week later, but MP cancelled it due to fog and its effects on measurements. Still can't use the boat. Final test (and I'm not condoning this ), I stuffed my tips with steel wool. Had to do 3 passes. First was at 78, second was at 80 and third was at 84. Average 82 and a pass. Voila, no more steel wool, or should I say evidence. Only risk is creating too much back pressure, so it took a little trial and error.

BTW, saw your post on OSO. Great boat, great deal.

Wow, why didn't we think of that? Would have been a lot cheaper. Course then, we would have been stopped again and invited to test again..

[codeman671]

Originally Posted by sunsationdave

Hello Codeman671
my 2 sunsations
288 and/32ss both had mufflers and never had a problems with the mp
my new formula 310ss has 2/ 496mags with mufflers and captians call exhaust
it is below 82 either way.It was passed this year switchable exhaust as long as it is under 82 on newer boats. last weekend I noticed a GF boat at your dock. Yep thats me flying by with the blue 310ss formula hitting the air horn
anyways good luck with the GF boat . if the speed limit goes away I will have a new 36SSR with 700s

Ahh, so you are the mystery formula that keeps beeping. I had no idea who it was. The 36SSR is sweet. I was looking to go Sunny this time but the Sonic was a great deal, even with the work it needed it complete it. I am hoping to launch it again tomorrow. We went with Hardin mufflers which quieted it down a lot. It had a nasty bark before.