Too Old

Joel,

Here's the information from Custom Marine's website.....


CMI Sound Elimination System™ mufflers are the next generation of sound reduction technology from CMI. These fully polished stainless steel mufflers enable boaters to operate their performance boats in stealth mode by reducing sound emissions to levels as low as 85 decibels (dB) -- below the most strict sound emission regulations. The mufflers are strategically engineered to reduce sound without restricting the exhaust or creating unwanted backpressure, which can inhibit the engine from reaching peak performance power. Mufflers can be installed on any exhaust system with tailpipes ranging from four to six-inches in diameter, which covers inboard or stern drivepowered recreational and performance boat applications up to 1200 horsepower. A superior design using 304 stainless steel results in fewer parts than competitive models, which will ensure long-lasting durability and reliability for marine applications.Clamp-on options include a 4-inch model to fit tip-style tailpipes by replacing transom tip to thru-transom version or simply clamp on existing tips; a 4.5-inch model to fit thru-transom tailpipes; and a 5-inch model for larger tailpipe diameters primarily used with CMI Big Tube Race Header Systems.

The 5-inch muffler can also be retro-fitted into 5- and 6-inch outside diameter tailpipes to accommodate larger horsepower applications. This option is available to OEM boat builders that order the muffler installed during the tailpipe manufacturing process for an inconspicuous appearance upon installation in the boat

GLH

Donkey Dicks at work once on plane, thought I would share for information purposes.

Lunatic Fringe

Ratickle,
What is the db limit for the fly by test in Wisconsin? Who is proposing the change to the legislation in Michigan so we can start fighting it NOW?

RonS

not sure what the flyby is but the only place that I ever really got hassled was Winnebago, and I have not heard of them doing fly bys. I actually have'nt heard of anyone getting hassled this year either, does'nt mean that they have'nt but I have'nt heard of anyone

epeek

I have a DB meter.So far I have tested 2 boats with the cmi
sound elimination system. One with 500 efis. One with 525's.
Neither will pass the 90 db at 1 meter requirment. Both tested
out at 91-92 DB's. Unfourtunatley,up here, they wont give you
1/10 of a DB over 90. Its "fix it or get it off the lake". My 35X
with 496's barely passes with the silent choice on!!!! 89.7 DB's

Too Old

Guess there's no need to bring test mufflers up for Columbus Day weekend then.......

otis311

I think Im good with my noise. I have passed many Patols and not one of them has attempted tp pull me over.. The day Rick checked me it was windy, there was alot of ambient noise and there were woods and a mountain directly behind me. Under true conditions. I will be real close.

Fred, We will check again while you are up here

el indio

Turn off 1 motor. they will think your broken or really trying to be quiet.........

Ratickle

Here is the current Wisconsin law. I edited it some because it is very long with a bunch of training and education requirements.

NR 5 .125(1)(b) ,An officer requesting a boat operator to submit to a noise test shall test the
boat using testing methods J34a, J1970 or J2005 .

SECTION 5. NR 5 .125(3)(b) is created to read :
NR 5 .125(4) CUTOUT MECHANISMS . No person may operate a boat t hat is equipped with a
muffler cut out, by-pass sw itch or similar device unless the operator of the boat can demonstrate at
the time of inspection that the boat cannot operate contrary to s . 30.62(2)(b),

NR 5.125,(3)(b) Operation standard. Noise level testing procedures J34a, J1970 or J2005
of the Society of Automotive Engineers shall be adhered to by boat operators when requested to
submit to one or more of them by officers conducting noise tests on boats operating in the state of
Wisconsin .

Ratickle

Here is the current Michigan law

6.10 Equipment Requirements

A. Misdemeanor—Equipment Requirements
MCL 324.80156 details the sound requirements for motorboat mufflers and
underwater exhaust systems. MCL 324.80156(1) states:
“Subject to subsection (2),* a person shall not operate a motorboat
on the waters of this state unless the motorboat is equipped and
maintained with an effective muffler or underwater exhaust
system that does not produce sound levels in excess of 90 dB(A)
when subjected to a stationary sound level test as prescribed by
SAE J2005 or a sound level in excess of 75 dB(A) when subjected
to a shoreline sound level measurement procedure as described by
SAE J1970. The operator of a motorboat shall present the
motorboat for a sound level test as prescribed by SAE J2005 upon
the request of a peace officer. If a motorboat is equipped with more
than 1 motor or engine, the test shall be performed with all motors
or engines operating. To determine whether a person is violating
this subsection, a peace officer may measure sound levels pursuant
to procedures prescribed in SAE J1970, issued 1991-92.”
A person who violates MCL 324.80156(1) is guilty of a misdemeanor
punishable by:
• imprisonment for not more than 90 days; and
• fine of not less than $100.00 or more than $500.00.
MCL 324.80156(6). In addition, the person must install a muffler or
underwater exhaust system that meets the act’s requirements before putting
the vessel back in use. Id.
Note: The DNR has promulgated 22 different rules dealing with
equipment requirements for vessels. R 281.1231 to 281.1252.

*MCL 324.80156(2) allows the DNR to establish rules for alternative sound level tests and maximum decibel levels.