Can any mufflers pass 90 decibels ?
 

They are really crackin down here in Lake George.
I bought a decibel meter and have been testing
freinds boats. If the engine has any H.P at all
the are all coming in at around 94-95 Decibels.
So far one had CMI units,another had Hardin Marine
Units. My 35 EX with 496 ho's comes in at 89.7
with the silent choice turned on! I calibrated my
meter with a LGPC cop when he was testing my boat
and both of ours read exactly the same.

Re: Can any mufflers pass 90 decibels ?
 

What standards does New York use for testing? I am surprised you were at the threshold of 90 db with your captains call on. SAE J2005 test is specific as to the conditions and distances of testing procedures. The only mufflers I have heard passed did so with water injection into the mufflers also. Do you have water or run dry? One friend here in West MI has Borla's on his Cig. It passes now and he runs dry. I do know we need to do more. They keep modifying the laws to make things more restrictive here also. I know both my old boats pass SAE J2005 but neither will pass SAE J34 which is currently being proposed. The new one won't pass either law! Let me know what you find out on the law.

Re: Can any mufflers pass 90 decibels ?
 

The test is 1 meter off the transom. I believe in my case there
is some leakage thru the hull even with the silent choice
turned on. It is still kinda of lumping sounding even when on.
Also its a Fountian. I think the platform tend to amplify the low
tones. Its 90 decibels on the "A" scale,wind under 12 mph,
with the meter set on slow response.

Re: Can any mufflers pass 90 decibels ?
 

Rick,

I think we need to test run a set of CMI sound elimination mufflers. I have had a few people tell me they are the best noise reduction with no back pressure issues.Maybe we can get them to send up a trial pair for people to try and have tested while on the water.My mufflers are slip on,so at the next meeting I can let people try them to see if there boat can pass with them as well as other brands that maybe other members can bring with them.Let me know what your thoughts are.


Nordic95 (detainee) aka seaswirl 16

Re: Can any mufflers pass 90 decibels ?
 

I put livorsi/northstars on a pair of 540's, they will pass the test, work the same as the cmi's.

Re: Can any mufflers pass 90 decibels ?
 

I was tested at 68db w/o mufflers !!

Re: Can any mufflers pass 90 decibels ?
 

or should I say ..... muffler

Re: Can any mufflers pass 90 decibels ?
 

I tested a Formula with Silent Thunder, single engine. It was between 89 and 90, with the drain plugs IN. With the drain plug out it was 91-92

Test is 1 meter off the transom, and 1 meter off the water, so if you have exhaust that exit under a fiberglass swim platform, it "should" help. The way I read the SAE standard, is transom. If they have a boat with built in swim platform, and they use the back of the swim platform it lowers the db a lot. Just by moving back 1 foot, the boot I tested dropped to 85db.

I guess EVERY Hacker on LG, needs to get a noise ticket, becasue none of them can pass 90db

Re: Can any mufflers pass 90 decibels ?
 

Not with 1100's :mad:

Re: Can any mufflers pass 90 decibels ?
 

Here is most of SAE J2500 testing procedures. It actually doesn't say transom, it says vertical projection. Does the NY law say SAE J2500 or 1 meter/1 meter? There is a huge difference when in court or testing under a strict set of rules set up by SAE Engineers.

Excerpt from SAE J2500
(copied and pasted from pdf)

4. Procedure

4.1 Measurement Site—A suitable site is a body of water free of large obstructions or reflective surfaces such as
buildings, boats other than those involved in this procedure, large embankments or breakwaters, etc. for a
minimum distance of 8 m (25 ft) from the boat being measured. The boat being tested shall either be moored
to a dock or lashed to another boat. If moored to a dock, the dock shall be of open construction so that it
presents a minimum of reflecting surfaces. If the measurement is made in open water, the boat being
evaluated shall be lashed to the measurement boat to prevent relative motion and to allow positioning of the
microphone in the prescribed location. The measurement boat shall be positioned to minimize reflected
sound.

4.2 Boat Operation—The engine shall be operated at low idle speed within the engine manufacturer's
recommended operating range, in neutral gear if so equipped. For motorboats without a neutral gear, the
engine shall be operated at its lowest operational speed. The engine shall be operated for a sufficient amount
of time to allow water to flow through the exhaust system before taking measurements.

4.3 Measurements

4.3.1 The microphone shall be placed at a distance of 1.2 to 1.5 m (4 to 5 ft) above the water and no closer than
1m (3.3 ft) from the vertical projection of any part of the boat in the area adjacent to the exhaust outlet(s).

4.3.2 The meter shall be set for slow response and the A-weighting network.

4.3.3 The observer reading the meter shall not be closer than arm's length from the microphone to minimize sound
reflections.

4.3.4 The applicable reading shall be the average sound level measured during a period when the background
sound level is at least 10 dB lower than the measured sound level. Background sound level includes wind effects, noise from boats other than the one being measured, wave action, boat wakes, and other extraneous
noises.
Peak readings of intermittent sound levels created by wave slaps or changes in sound level due to
wave action and/or engine speed variation shall not be included in the applicable reading.

4.3.5 The observer shall record the applicable reading and the background sound levels taken immediately before
and immediately after the applicable reading.

5. General Requirements

5.1 The measurements shall be conducted only by persons qualified by training to perform these measurements.

5.2 Proper use of all test instrumentation is essential to obtain valid measurements. Operating manuals or other
literature furnished by the instrument manufacturer should be consulted for both recommended operation of
the instrument, and precautions to be observed.

5.3 Proper acoustical calibration shall comprise the complete measurement system including extension cables,
etc. Field calibration shall be performed immediately before and after each test sequence.

5.4 A measurement shall be invalid if changes in the background sound level affect the applicable reading.

5.5 The use of the word "shall" in the procedure is to be understood to be mandatory, while the word "should" is to
be understood as advisory.

PREPARED BY THE SAE MARINE SOUND LEVEL SUBCOMMITTEE OF THE SAE MARINE TECHNICAL COMMITTEE AND THE SAE SPECIALIZED VEHICLE AND EQUIPMENT SOUND LEVEL COMMITTEE

Re: Can any mufflers pass 90 decibels ?
 

had my boat tested after a ticket. and the gil switchalbes did not past read a 96. so i set up some down pipes to pass.
todd

Re: Can any mufflers pass 90 decibels ?
 

Seems to me if you took pictures or video of the LEO conducting one of these tests you'd be able to find enough mistakes to beat the ticket in court. I don't see how they can accurately perform the test with so many procedures and variables.

Re: Can any mufflers pass 90 decibels ?
 

Funny thing is that I had this test done twice and tried a third time in three days.I read the rules and I cant find anything SHE did to be wrong,damn I hate when they are right.But I cheated and made it the second time after I received a ticket for the first voluntary sound check.

Nordic95

Re: Can any mufflers pass 90 decibels ?
 

My Seaswirl 16' passed to,but you dont see me rubbing it in. :mad:

Nordic95

Re: Can any mufflers pass 90 decibels ?
 

BENNINGTON !!

Re: Can any mufflers pass 90 decibels ?
 

We use the exact same meter the cops use out there.

Re: Can any mufflers pass 90 decibels ?
 

They use 2005

from the web site
http://www.nysparks.com/boating/enforcement.asp

What is test 1970? I've never heard of it.

I always thought that 2005 said transom. My bad. But that could be an interesting loop hole on a boat like a Formula with silent thunder. Where is the exhaust "really" coming out? The transom outlets, or the silent thunder outlets. 1 meter of transom compared to 1 meter off teh silent thunder is 12-15" further back, which I would think would cut out a lot of noise.

Re: Can any mufflers pass 90 decibels ?
 

Do I understand the part where the background noise must be 10 db BELOW the engine? So if the engine reads 95, and the background reads 86, it is NOT a valid test?

Re: Can any mufflers pass 90 decibels ?
 

Duke, It is the test from shore. Also unenforceable under the current rules. They try to make it as if you are driving by shore and a water policeman with a DB meter gets a reading and you are hit with a big ticket. And yes, the 10 DB rule you have correctly interpreted. I currently believe Wisconsin has the most restrictive rules. Soon to be passed by Michigan (next year?)if they have their way.


The SAE J1970 standard Shoreline Sound Level Measurement Procedure and the SAE J2005
standard Stationary Sound Level Measurement Procedure for Pleasure Motorboats, were both
adopted in December 1991. These standards were the second and third boat noise measurement
standards created. SAE J1970 and J2005 were developed to provide alternative field procedures
for measuring sound level emitted from pleasure motorboats. Their development sought to
create a measurement standard directly emulating the 75 dBA shoreline noise limit in the Marine
Safety Act and to avoid the requirement of a pass-by course. The SAE J1970 and J2005 are the
only two boat noise standards currently specified by the Michigan Marine Safety Act.
The SAE J1970 Shoreline Sound Level Measurement Procedure, was adopted for
measurement of sound emitted by pleasure motorboats in operation on waterways where sound
level restrictions apply. The standard requires placing a sound level meter on the shore of a body
of water, a dock projecting out from the shore into the body of water, or a raft/boat moored to a
dock or anchored so that the sound level meter is not more than 6 meters from shore. The SPL
measurement is taken after the boat accelerates full throttle away from the measurement location
for 30 seconds to emulate the Michigan Marine Safety Act's requirement for a 300 foot offshore
distance to boats operating at full throttle. The sound level meter must to be placed 1.2 meters to
1.5 meters above the water and no less than 0.6 meters above the platform, or shore, surface
[SAE J1970]. The Michigan Marine Code sets a 75 dBA (fast) SPL maximum acceptable sound
level from this standard measurement procedure.

Re: Can any mufflers pass 90 decibels ?
 

WIGGLER4490 should know, he has tried everything!

Re: Can any mufflers pass 90 decibels ?
 

Went the Donkey Dick way up here works great.. doesn't look as bad as I tought either...

On the lake here it's 82 Dba at 50 ft.

Re: Can any mufflers pass 90 decibels ?
 

epeek,

Get yourself in the same rig otis is currenty in... you'll be fine. :D

BTW, where's my t shirt and all the fancy paper work for my $100.00 Lake George Boat Club membership????

Re: Can any mufflers pass 90 decibels ?
 

He went the Donkey Dick way and now they are cracking down on the noise level at speed I believe. Hopefully he will come on with an update. I am trying to find out everything I can because I only want to modify once.

Re: Can any mufflers pass 90 decibels ?
 

If anyone is interested in CMI Mufflers, give us a call. We'll cut you a decent deal.

Kirk
Ateco Engine and Dyno Shop

Re: Can any mufflers pass 90 decibels ?
 

Give me a shirt size and Ill get it to you

xxl ??

Re: Can any mufflers pass 90 decibels ?
 

Send me a PM when you work out the dry exhaust muffler deal.

Thanks,

Neil

Re: Can any mufflers pass 90 decibels ?
 

Hey Bob I was just rattling your chain bro... You guys put on an incredible run. Food, drinks, entertainment, etc. was incredible. I was more than happy to donate to your boat club.

Looking forward to having my boat at your next run.

Neil

Re: Can any mufflers pass 90 decibels ?
 

Last summer I was busted for being too loud. Twin 1400's. I even have a DB meter to test mufflers. 3 sets later I bought some CMI's mufflers and they tested at 90 DB my meter and passed the required test by the Sheriff's water patrol. Illinois is 90 db. Once you get a ticket you are not allowed on the water until you pass. THE CMI MUFFLERS DO WORK!

Re: Can any mufflers pass 90 decibels ?
 

Have you run any tests at speed? Currently Wisconsin law is 88 db stationary, 75 db at shoreline, and 86 db passby. The passby is at WOT under SAE J34. Michigan is threatening to pass the same as Wisconsin and legalize the "Noise Gun".

This is a clipped section from the current Ohio law and a similar proposal would be included in Michigan's. I believe CMI's and Shotgun's would not be legal under this rule. The guys in Ohio have mostly said they don't enforce it there unless they get a complaint.
No person shall operate or give permission for the operation of a powercraft on the waters in this state that is equipped with an altered muffler or muffler cutout, or operate or give permission for the operation of a powercraft on the waters in this state in any manner that bypassed or otherwise reduces or eliminates the effectiveness of any muffler or muffler system.