As Ram Air (literally ram air ) are referred to motor vehicles the intake ports are arranged so that a forced induction and thus an increase in performance is achieved by the dynamic pressure of the relative wind engine intake systems.
At high speed, the combustion chambers is supplied more air for combustion by ram-air systems, whereby more fuel may be burned, resulting in an increase in performance.
However, in addition to the necessary cooling air openings Ram -air openings can also worsen the drag coefficient of the vehicle. This puts the effect in so far as the greater air resistance increases quadratically with the speed, the performance gain by the ram air effect but only linearly. This is related to the desired effect particularly important, since this is only significant at high speeds, so in that very area where aerodynamics plays an increasingly important role. To increase the speed of 300 km / h to 400 km / h, a significantly higher increase in power is required, as for an increase of 200 km / h to 300 km / h This effect can not be achieved through ram-air effects alone, so ram-air systems do not replace other measures of performance increase, but can only supplement.
In modern bikes with Ram Air systems, intakes are generally low resistance attached to the front side of the front panel. Ram air in some systems, the air is supplied via issued Ansaughutzen which is aerodynamically less efficient.
In prototype racing series such as Formula 1 cars are often designed with large, forward-facing intake ports that use the ram-air effect. Especially in Formula 1 perforation of the airbox was prescribed to limit the power of the vehicles in the 1990s by the regulations.