Spoiler (automotive)

With spoiler, a vehicle attachment part of a car or truck is called, whose central feature is to change the Fahrzeugumströmung.

Distinction between

The terms spoilers and wings are used in common parlance often used interchangeably. The term to is derived from the English usage spoil and literally means " ( something ) destroy, damage ". The spoiler is flowing on one side only. As part of the vehicle it interferes with the air flow, and thereby affects the aerodynamics. So its function is primarily that of an air deflector or air deflector and must be considered in conjunction with the aerodynamics of the vehicle body.

From a leaf is called a rule, when both upper and underside of the component are overflowing. A wing is driven, so contact pressure for better traction produce, and is able to work independently or aerodynamically additional effects in interaction with the body aerodynamics.

Operation of a spoiler

In a car, especially in sports and racing cars, spoilers are rigid components in plastic, rare metal or carbon, which with the aim to reduce air flows around while driving the buoyancy of a body. They are thus air deflector or air deflector. The reduction of the buoyancy force enhances the transmission of forces on the ground and thus the handling characteristics, especially the lateral acceleration and therefore cornering speed, the driving stability and braking distance at high speeds.

However, the reduction in the lift forces is usually with an increase in the air resistance associated (see polar ). Under efficient spoiler is understood in the automotive aerodynamic a component which reduces the lift and thereby the air resistance increases as little as possible, or even reduced, in the ideal case.

Contrary to popular notion, the reducing buoyancy force often does not act directly on the spoiler itself, but is caused by the change in pressure distribution on the body of the vehicle. In front of a vehicle on a top superscript spoiler ( see adjacent picture of Lancia Thema ) upstream increases the local pressure on the surface. The perpendicular to the road acting on the surface downward force, the product of pressure and area, thereby also increases, thus ensuring the desired buoyancy reduction.

At the same time, the flows can be there but disturb very effective with little effort and little additional resistance. This is precisely the purpose of the spoiler: the front, the air is to the side rather than up over the hood distracted behind the air is deflected up or totally blocked as the first Audi TT and some series Porsche. If the air is directed from the front spoiler sent to the extra-wide front wheels, the total resistance can even reduce. But this is only the case if the spoiler takes components with very high air resistance of the flow. But then the term aerodynamic fairing attached. In general, the total resistance increases by a spoiler.

Designs

We can distinguish the following categories mainly:

• Spoiler or front spoiler, which lower the lift on the front axle. In good design of the air resistance can be additionally reduced, and the supply of cooling air for the motor and brake can be improved (see aerodynamics)
• Rear spoiler, which lower the lift on the rear axle
• Spoilers, part of the front and / or rear wheel to improve Radanströmung
• Side spoilers or side skirt panel to the side of vehicles, even at the front corner of a truck to improve the dirt kept free of the door area

Formation

The first spoiler, the firm Kamei ago in 1953. The so-called " depth control " should address the significant lift on the front axle of the VW Beetle, but then found no favor. Some years later, a measurement in the wind tunnel that the sweeping design the buoyancy reduced by 16%.

In the 1960s, Chaparral led a spoiler in racing.

Current regulations in Germany

Since November 2004, wide sweeping rear spoiler made ​​of aluminum are no longer admitted by the traffic regulations. It was this generally is particularly massive, sharp-edged spoiler, which were inspired as a fad among other things, by the The Fast and the Furious film series. In crash tests, especially during simulated collisions with pedestrians, a greatly increased risk of injury was found.

All spoilers must be registered, provided they have no general operating permit (ABE), that is, the holder of the vehicle is required, the spoiler and the assembly with a licensed expert and to be approved. Buyer of spoilers should be taken to ensure that accompanies either ABE or parts certificate § 19.3 (vehicle specific ). An entry in the vehicle documents with a material certificate / confirmation of a material should no longer be possible.

Criticism

Hobby Tuner bring spoiler ( frits bar ) often in the dead water area of ​​the vehicle (for example, the VW Golf at the lower edge of the rear window ), where the desired aerodynamic effect physically no longer can occur. The component is then only the appearance is seen fluidly but ineffective.

In addition, one also frequently sees rear spoiler designs which have very large (negative ) angle of attack, which makes for a very uneven distribution of front- and Hinterachsauftriebskraft and may even adversely affect the handling characteristics of the vehicle.

Generally speaking, the basic idea of the hobby tuner is already problematic: how and whether a spoiler works at all, is without extensive measurements hardly predict, so that the effect subsequently fitted spoiler without a properly conducted wind tunnel measurement or flow simulation is unknown.