ATV Exhaust Decibel Guide

As you probably know, most riding areas are really cracking down on the allowable noise limit. In many cases it's because there are houses and communities around our riding areas. Most of us like to ride at night, but the people in the houses are trying to sleep then. They then complain to the Forest Service or whoever manages the riding area and then we have sound decibel restrictions.

Every area that you ride in will probably have a different restriction, especially state to state. Even within a state, you will find different limitations. For example, Sand Lake Recreation Area in Oregon limits your allowable decibels to 97. However, just miles away in the Oregon Dunes Recreational Area, you may not exceed 93 decibels. On most California and Maine Public Lands where riding is allowed, the max is 96 decibels; at Silver Lake Michigan, it's 92. Special use areas may have other allowances - the Goldendale MX track in Washington state has a 99 decibel allowance. Higher, but not easy to stay within if you are prepping a quad for MX competition. Your public riding area probably does have a limit - it may not have been easy to find out or even aggressively enforced in the past, but you can count on enforcement increasing in the coming years, and those limits are already dropping.

This is why we have put together this guide. We have included at least one exhaust by a couple of manufactures for most of the sport ATV's, all between 90 and 100 decibels. Prices range from $200 to almost $600, and the amount of dollars you spend doesn't necessarily translate to the amount of "quiet" you get. Since more power is generally what you are looking for when you are shopping for an aftermarket pipe, remember the effect quieting that pipe down has - we are being forced to accept that trade off. There are more options coming out though, and soon you shouldn't have to sacrafice as much "umph" to get your "shh".

To be fair and give you as many options as possible, we repeatedly contacted over a dozen different after-market exhaust manufacturers. Included in this listing are those that were willing or able to provide a stated decibel level for their pipes. We would have liked to have given you many more, for all makes and models, but found it nearly impossible to get some manufacturers to even call us back. So we appreciate the vendors that cooperated and had the information readily available.

Testing

The official way of testing DB limits is defined by “SAE J1287”. To do it the approved way as set forth by the Society of Automotive Engineers, you need a sound level meter and calibrator, a sound level meter windscreen, a tachometer, and a tape measure. It is possible to do this basic sound test on your own though. It really isn't that hard to figure out what DB your exhaust measures out to. It will cost you about $60, but that is way cheaper than the fine in an area if you are too loud.

The first thing you are going to need is a sound level reader. You can get an adequate one for about $35 at Radio Shack. The next thing you will need is a tachometer. This should cost you about $20. To get the correct DB, there is a certain RPM you need to test it at. If you have a four-stroke, you divide the stroke (in mm) by 250,000, for a two-stroke you divide it by 200,000. (We have also heard you can just divide your total RPM's in half, but don't know if this always works out correctly.)

Get a friend to hold the tachometer on the handle bars, and rev the engine up to the right RPM. You need to be holding you sound level reader exactly 20 inches from the exhaust at a 45 degree angle. Now you have your DB rating for your ATV.

Know it, and know the limitation for where you wish to ride. If you are looking to upgrade your ATV with an aftermarket exhaust, be aware of the sound level you may be buying into. Noise level infractions are one of the greatest weapons enemies of public riding have in their arsenal to shut down our public riding areas – don't contribute to the problem!

See related Press Release from American Honda Motor Co.