Airbox

Older engines drew air directly from the surroundings into each individual carburetor.

[2] Since the 1990s, engine designers also sought to exploit the properties of oscillating gas to improve performance.

Many high-performance motorcycles have the airbox fed from funnels in the front of the bike, where increased pressure forces more air into the intake and thus improves power.

Examples of this ram-air intake construction are the SRAD models of the Suzuki GSX-R750, the Kawasaki Ninja ZX-6R or the BMW S1000RR.

The resonance is typically chosen to be at a medium speed where torque otherwise drops, caused by valve timing overlap.