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jhwentworth

Snowmobile exhaust systems

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HB 591 has been signed into law, and some changes were made to the snowmobiles  rules around exhaust systems. It appears that a different SAE standard will be used, and all sleds must comply with that standard.

No person shall sell, offer to sell, or operate in this state a snowmobile which produces total vehicle noise of more than 82 decibels sound pressure on the "A" scale as measured using the Society of Automotive Engineers (SAE) J2567 standard.

No person shall modify any snowmobile in any manner that shall amplify or otherwise increase total vehicle noise above that emitted by the snowmobile as originally manufactured with the original muffler nor shall any person operate any such snowmobile.  The provisions of this paragraph shall not apply to snowmobiles operated at permitted snowmobile events as defined in the department's administrative rules, FIS 1501.01(d).

No person shall operate a snowmobile manufactured after February 1, 2007 that does not display on its exhaust system's critical components the letters “SSCC Certified,” a visible and unaltered certification marking issued by an independent organization, the Snowmobile Safety and Certification Committee (SSCC), that certifies snowmobiles for uniformity of safety features and noise levels.  The letters shall be legible and have a minimum height of 4 millimeters.  The marking shall be on the exhaust silencer, visible and legible to an observer by lifting a snowmobile hood and without detaching or dismantling any component parts.  The markings shall be embossed and pressed or attached in a similarly durable manner to the outer surface of the exhaust silencer assembly, and shall be resistant to alteration.  The markings shall be so affixed that it shall be difficult to remove, replace, or alter without detection.

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That seems to clear the whole 'I can modify my sled as long as it meets the sound requirements' problem better than a flat out 'must have factory exhaust'. Problem is, I don't think any of the aftermarket companies get their parts certified. If they go to the expense of doing that now, riders may have the option of a lighter exhaust system that is legal. Seems like a good thing to me. 

 

Note - I will be leaving my factory system on either way...

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5d437bf347311_DSCN1727(Small).JPG.9ebb17f8d9af434605568e08390f897b.JPGI'm glad the new law excludes vintage sleds " No person shall operate a snowmobile manufactured after February 1, 2007 " otherwise my old Rupp Nitros with "rams horn" exhaust would not comply with DB numbers for sure.  I can feel a confrontation  with F@G is in my future, as soon as they hear me coming.  Very few of them know what constitutes "stock" from that far back...

The new law is a good thing and needed, by what I hear around Young's on weekends.  Some aftermarket pipes are ridiculous and can irritate the heck out of land owners who are keystones of lots of trail systems in the state...

pathB)finder

Edited by pathfinder

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2 hours ago, pathfinder said:

I'm glad the new law excludes vintage sleds " No person shall operate a snowmobile manufactured after February 1, 2007 " otherwise my old Rupp Nitros with "rams horn" exhaust would not comply with DB numbers for sure.  I can feel a confrontation  with F@G is in my future, as soon as they hear me coming.  Very few of them know what constitutes "stock" from that far back...

 

pathB)finder

The first part of the new reg would seem to include all snowmobiles, including vintage: No person shall sell, offer to sell, or operate in this state a snowmobile which produces total vehicle noise of more than 82 decibels sound pressure on the "A" scale as measured using the Society of Automotive Engineers (SAE) J2567 standard.

Back in the 1975 the regs called for a max of no more than 78 dB(A) from a distance of 50 feet while traveling at full throttle when tested under the Society of Automotive Engineers (SAE) J192 procedures.

The new regs max of 82 db uses SAE J2567 which measures noise while the sled is stationary and at 4000 rpm and the microphone about 13 feet from the sled.This standard seems designed to simplify the work of law enforcement in measuring sound after a stop. Here's something from the IASA: http://www.snowiasa.org/wp-content/uploads/2015/06/2015-IASA-Sound-Test-Presentation.pdf

6.0 Procedure
6.1 The snowmobile shall be parked at the test site with an operator seated in the normal operating position, and
the forward traveling path of the snowmobile clear of obstructions as required in 5.1.
6.2 The brake shall be set throughout the test.
6.3 The engine shall be started and run until reaching normal operating temperature range, as specified by the
manufacturer.
6.4 The operator shall slowly open the throttle until a steady 4 000 rpm ± 250 rpm engine speed is achieved, while
holding the snowmobile stationary by applying the brakes.

7. Measurements
7.1 The sound level meter shall be set for A-weighting network and slow dynamic response.
7.2 The sound level meter shall be calibrated and adjusted, if necessary, so that the meter reads within 0.1 dB of the true level at the microphone.
7.3 The microphone shall be located on the side of the snowmobile towards which the exhaust outlet(s) is (are) directed. This is generally on the right side. The longitudinal axis of the microphone shall be in a plane parallel to the ground plane. There shall be no physical attachment between the snowmobile and the microphone/sound level meter.
7.4 The microphone shall be located at a distance of 4.00 m / 157.5 in from the longitudinal plane of symmetry and 1.22 m / 48.0 in above the ground plane in line with the exhaust outlet. If there is more than one exhaust outlet.

 

I'd guess that a lot of the real old stuff won't pass the 82 db limit, but we won't know until tests are done on the trail.

 

Edited by jhwentworth

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When was the last time you met up with a F@G crew with all the gear necessary to make a judgement?  Or even understand all the steps in making the test?

It's basically a subjective decision of the officer on scene. Most times it is influenced by the mood and conversation that is carried on with the officer, and how "in control" the offender deals with the officer.

pathB)finder

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What I'm suggesting is that the new regs simplify the measuring process, I'm not saying that there isn't a good deal of discretion in the stop. The old regs called for a measurement process that wasn't possible in the field.

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The first part is to handle ''fade''. It is a comparable to the OHRV 96dB regulation. Stock exhaust tend to lose sound dampening ability over time, and when deemed beyond the maximum allowable dB limit need to be replaced. The exhaust ''stamp'' has various renditions going back to the mid 80s, and was not used by all manufacturers... sometimes even being a sticker that burned off. The exhaust engraving covers all manufacturers in 2007, and should be easily read for the life of the component. 

 

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I do not support loud pipes on any trail sled, but, IMO this allows for abuse and revenue generation via an angry agent. I worked at a bike shop for years doing inspections and that DB test would fail even the quietest stock bike when done to the letter. I discussed this with the state inspector and he acknowledged and only suggested using "your own discretion". 

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Well, when done to the letter the exhaust had to pass at the manufacturer for them to sell the machine. That ''bike'' one is 82dB at the factory. ''Fade'' to 96dB is specification by the AMA. NH simply adopted it.

 

 

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I hope this gets pushed for motorcycles as well. 

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13 hours ago, John Mercier said:

Off Road are the same. On Road is a different standard within NH statute.

 

I agree that on road and off road vehicles are treated very differently. One common thread though, is that the statutes defined a testing procedure that was very difficult for law enforcement to follow. That testing procedure was recently changed for the off road vehicles and law enforcement should be able to more easily comply with the law.

Here's the procedure for testing a street bike in the field.

New Hampshire law limits the volume of motorcycle exhaust noise at different levels, depending on speed and engine type.

  • 92 decibels when operating at idle speed
  • 100 decibels for 3 or 4 cylinder motorcycles when operating at 5,000 rpm or 75% of maximum engine speed
  • 96 decibels for all other motorcycles when operating at 2,000 rpm or 75% of maximum engine speed

State law is specific about how and where motorcycle noise should be measured: by a meter held at a 45-degree angle approximately 20 inches from the motorcycle’s exhaust pipe, in an open test area free of buildings, parked vehicles, signs or other sound-reflecting objects.

Fines for violations range from $100 to $300. There’s no exception for antique motorcycles.

https://www.citizenscount.org/issues/motorcycle-noise

The city of Portsmouth is attempting to work through the testing procedures.

We’re going to be paying attention and have the equipment to enforce the laws,” stated Captain Frank Warchol of the Portsmouth police department. “The initiative was put together because people were complaining,” he stated. The Portsmouth police department dispatched two officers to train with the New Hampshire state police to use new equipment for measuring noise levels from motorcycle exhaust pipes. Captain Warchol notes that the Portsmouth police department now has a decibel reader, an anemometer, and a “custom-made tool to take the sound readings at the 45-degree angle required for an accurate reading.”

Recent changes in laws/regulations have made noise violations easier to prosecute for off road vehicles and harder to prosecute for on road motorcycles.

 

 

 

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