Editing Restrictor plate (section)

{{short description|Device installed at the intake of an engine to limit its power}}
{{refimprove|date=August 2010}}
[[Image:Restrictor-Plate-Rendering.png|right|thumb|Artist rendering of a NASCAR restrictor plate]]
A '''restrictor plate''' or '''air restrictor''' is a device installed at the [[intake]] of an engine to limit its power. This kind of system is occasionally used in road vehicles (e.g., motorcycles) for insurance purposes, but mainly in [[automobile racing]], to limit top speed to provide [[Balance of performance|equal level of competition]], and to lower costs; insurance purposes have also factored in for [[Motorsport|motorsports]].