Here's a great little piece of animation work.
Although it is intended to illustrate how a muffler, or silencer works, the same technology applies to reducing the intake sounds on our Bikes, just reversed!
It shows how the AirBox "
Resonator" functions. The Resonator is the plastic piece with a center opening inside the airbox that so many incorrectly call a
restrictor, not really knowing what it is, or innocently repeating what countless others have incorrectly stated.
HowStuffWorks "How Mufflers Work"
The resonator works by throwing sound waves back at incoming waves, cancelling out vibration, hence noise. These became required due to EPA and other "noise" legislation requirements.
Removing it will increase the intake noise coming out of the airbox, or in some cases a simple air filter enclosure. In some applications, it may increase airflow, but usually when someone removes one of these mysterious plastic devices, they also change to a freer flowing filter element, so the benefit is clouded.
Was it the filter element that eventually provided the increased airflow? Or did removing the
Resonator allow more air in? Is it practical to take wholesale advice from someone who incorrectly states the name and function of am OEM part?
Probably a little of each.
Ride Safe!
Bob
Re: Airbox Eruditions... 
