Posted January 9, 2007

How to choose or test an exhaust for ATVA competition

With the announcement that Pro racers will be held to 99db at the AMA Pro ATV events, and armatures at the ITP-Moose Racing ATVA National Motocross series will also be tested, you need to know: Does your exhaust measure up?

If you are thinking about purchasing a new muffler or exhaust system, the first thing you should do is ask the supplier, "What is the db limit of this pipe?"

Every exhaust manufacturer knows the db limit of their pipes and can help you with your decision.

How does your current system measure up?

The new rule uses the Society of Automotive Engineers J-1287 test standard. The test is performed with a sound meter 20 inches from the exhaust, with the engine running a designated RPM. For example, all current 450cc ATVs test at 3,750 rpm.

If you want complete details about how to perform the test, request a copy of the Stationary Sound Test Manual, produced by the Motorcycle Industry Council and available free from the ATVA. Just send an e-mail to Cathy Brown at the ATVA/AMA.

The booklet provides complete instructions on performing the test and lists the rpms at which the test should be performed for various models of ATVs and motorcycles.

© 2007, All Terrain Vehicle Association