![1987AudiSportQuattroS1PikesPeak](https://upload.wikimedia.org/wikipedia/commons/0/09/1987AudiSportQuattroS1PikesPeak.jpg)
A spoiler is an
automotive aerodynamic device whose intended design function is to 'spoil' unfavorable air movement across a body of a vehicle in motion, usually described as
turbulence
In fluid dynamics, turbulence or turbulent flow is fluid motion characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow, which occurs when a fluid flows in parallel layers, with no disruption between ...
or drag. Spoilers on the front of a vehicle are often called air dams. Spoilers are often fitted to
race
Race, RACE or "The Race" may refer to:
* Race (biology), an informal taxonomic classification within a species, generally within a sub-species
* Race (human categorization), classification of humans into groups based on physical traits, and/or s ...
and high-performance
sports cars
A sports car is a car designed with an emphasis on dynamic performance, such as handling, acceleration, top speed, the thrill of driving and racing capability. Sports cars originated in Europe in the early 1900s and are currently produced by ...
, although they have become common on passenger vehicles as well. Some spoilers are added to cars primarily for styling purposes and have either little aerodynamic benefit or even make the aerodynamics worse.
The term "spoiler" is often mistakenly used interchangeably with "wing". An automotive wing is a device whose intended design is to generate
downforce
Downforce is a downwards lift force created by the aerodynamic features of a vehicle. If the vehicle is a car, the purpose of downforce is to allow the car to travel faster by increasing the vertical force on the tires, thus creating more grip. ...
as air passes around it, not simply disrupt existing airflow patterns. As such, rather than decreasing drag, automotive wings actually increase drag.
Operation
![Chrysler Crossfire fastback blue rear](https://upload.wikimedia.org/wikipedia/commons/f/fc/Chrysler_Crossfire_fastback_blue_rear.jpg)
Since spoiler is a term describing an application, the operation of a spoiler varies depending on the particular effect it is trying to spoil. Most common spoiler functions include disrupting some type of airflow passing over and around a moving vehicle. A common spoiler diffuses air by increasing amounts of turbulence flowing over the shape, "spoiling" the
laminar flow and providing a cushion for the laminar boundary layer. However, other types of airflow may require the spoiler to operate differently and take on vastly different physical characteristics.
In racing cars
While a mass is traveling at increasing speeds, the air of the environment affects its movement. Spoilers in racing are used in combination with other features on the body or chassis of race cars to change the handling characteristics that are affected by the air of the environment.
Often, these devices are designed to be highly adjustable to suit the needs of racing on a given track or to suit the talents of a particular driver, with the overall goal of reaching faster times.
Passenger vehicles
![Toyota mr2 sw20 rear left](https://upload.wikimedia.org/wikipedia/commons/9/95/Toyota_mr2_sw20_rear_left.jpg)
The goal of many spoilers used in passenger vehicles is to reduce drag and increase
fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, wh ...
.
Passenger
A passenger (also abbreviated as pax) is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. The ...
vehicles
A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wate ...
can be equipped with front and rear spoilers. Front spoilers, found beneath the bumper, are mainly used to decrease the amount of air going underneath the vehicle to reduce the
drag coefficient
In fluid dynamics, the drag coefficient (commonly denoted as: c_\mathrm, c_x or c_) is a dimensionless quantity that is used to quantify the drag or resistance of an object in a fluid environment, such as air or water. It is used in the drag e ...
and lift.
Sports cars are most commonly seen with front and rear spoilers. Even though these vehicles typically have a more rigid chassis and a stiffer suspension to aid in high-speed maneuverability, a spoiler can still be beneficial. This is because many vehicles have a fairly steep downward angle going from the rear edge of the roof down to the trunk or tail of the car which may cause airflow separation. The flow of air becomes turbulent and a low-pressure zone is created, increasing drag and instability (see
Bernoulli effect
In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy. The principle is named after the Swiss mathemat ...
). Adding a rear spoiler could be considered to make the air "see" a longer, gentler
slope
In mathematics, the slope or gradient of a line is a number that describes both the ''direction'' and the ''steepness'' of the line. Slope is often denoted by the letter ''m''; there is no clear answer to the question why the letter ''m'' is use ...
from the
roof
A roof ( : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of te ...
to the spoiler, which helps to delay flow separation and the higher pressure in front of the spoiler can help reduce the lift on the car by creating downforce . This may reduce drag in certain instances and will generally increase high-speed stability due to the reduced rear lift.
Due to their association with racing, spoilers are often viewed as "sporty" by consumers. However, "the spoilers that feature on more upmarket models rarely provide further aerodynamic benefit."
Material types
![BMW M8 GTE spoiler](https://upload.wikimedia.org/wikipedia/commons/4/4a/BMW_M8_GTE_spoiler.jpg)
Spoilers are usually made of lightweight polymer-based materials, including:
*
ABS plastic: Most
original equipment manufacturer
An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...
s produce spoilers by casting
ABS plastic with various admixtures, typically granular fillers, which introduce stiffness to this inexpensive material. Frailness is the main disadvantage of
plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
, which increases with product age and is caused by the evaporation of volatile
phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
s.
*
Fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...
: Used in car parts production due to the low cost of the materials. Fiberglass spoilers consist of
fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth ...
cloth infiltrated with a thermosetting resin, such as
epoxy
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also coll ...
. Fiberglass is sufficiently durable and workable, but has become unprofitable for large-scale production because of the labor involved.
*
Silicone: More recently, many auto accessory manufacturers are using silicon-organic polymers. The main benefit of this material is its phenomenal plasticity. Silicone possesses extra high thermal characteristics and provides a longer product lifetime.
*
Carbon fiber
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...
: Carbon fiber is lightweight and durable but also expensive. Due to a large amount of manual labor, large-scale production cannot widely use carbon fiber in automobile parts currently.
Other common spoiler types
* Front spoilers: A front spoiler (air dam) is positioned under or integrated with the front
bumper
Bumper or Bumpers may refer to:
People
* Betty Bumpers (1925-2018), American activist, First Lady of Arkansas, wife of Dale Bumpers
* Dale Bumpers (1925–2016), American politician, governor of Arkansas and senator
* Bumper Robinson (born 197 ...
. In racing, this spoiler is used to control the dynamics of handling related to the air in front of the vehicle. This can be to improve the drag coefficient of the body of the vehicle at speed or to generate downforce. In passenger vehicles, the focus shifts more to directing the airflow into the engine bay for cooling purposes.
*
Pickup truck
A pickup truck or pickup is a light-duty truck that has an enclosed cabin, and a back end made up of a cargo bed that is enclosed by three low walls with no roof (this cargo bed back end sometimes consists of a tailgate and removable covering) ...
bed spoiler: This attaches only to the top of the
truck bed rails near the rear. Used with a bed cover, this spoiler is intended to reduce the air profile of the steep drop-off from the tailgate.
* Pickup truck cab spoiler: This is purposed the same as above, except focusing on the drop-off from the cab of the truck to the cargo bed.
Active spoilers
An active spoiler is one that dynamically adjusts while the vehicle is in operation based on conditions presented, changing the spoiling effect, intensity, or other performance attributes. Found most often on sports cars and other passenger cars, the most common form is a rear spoiler that retracts and hides partially or entirely into the rear of the vehicle, then extends upwards when the vehicle exceeds a specific speed, such as the active spoiler in the
Bugatti Veyron
The Bugatti Veyron EB 16.4 is a mid-engine sports car, designed and developed in Germany by the Volkswagen Group and Bugatti and manufactured in Molsheim, France, by French automobile manufacturer Bugatti. It was named after the racing driver P ...
. Active front spoilers have been implemented on certain models as well, in which the front spoiler or air dam extends further toward the road below to reduce drag at high speed. In most cases, the deployment of the spoiler is achieved with an electric motor controlled automatically by the onboard computer or other electronics, usually based on vehicle speed, driver setting, or other inputs. Often the driver can manually deploy the spoiler if desired, but may not be able to retract the spoiler above a certain speed because doing so could dangerously diminish the high-speed handling qualities of the vehicle.
Active spoilers can offer additional benefits over fixed spoilers. Cosmetically, they can allow a cleaner or less cluttered appearance when the vehicle is parked or traveling at low speeds when it is most likely to be observed. A spoiler that hides may be appealing to vehicle designers who are seeking to improve high-speed aerodynamics (for example the
Porsche 911
The Porsche 911 (pronounced ''Nine Eleven'' or in german: Neunelfer) is a two-door 2+2 high performance rear-engined sports car introduced in September 1964 by Porsche AG of Stuttgart, Germany. It has a rear-mounted flat-six engine and origin ...
or
Audi TT), without drastically changing its appearance. Hiding a spoiler at low speeds can improve aerodynamics as well. At low speeds, a fixed spoiler may actually increase drag, but does little to improve the handling of the vehicle due to having little airflow over it. A retractable front spoiler can reduce the scraping of the car on curbs or other road imperfections, while still reducing drag at high speeds.
Powered fans, such as in the
Chaparral 2J
Chaparral Cars was a pioneering American automobile racing team and race car developer that engineered, built, and raced cars from 1963 through 1970. Founded in 1962 by American Formula One racers Hap Sharp and Jim Hall, it was named after the ro ...
, do the equivalent of spoilers and increase the downforce and hence traction and handling of the vehicle. Research continues on the use of fans to alter the aerodynamics of vehicles.
Other vehicles
Heavy trucks, like
long haul tractors, may also have a spoiler on the top of the cab in order to lessen drag caused by air resistance from the trailer it is towing, which may be taller than the cab and reduce the aerodynamics of the vehicle dramatically without the use of this spoiler. The trailers they pull can also be fitted with under-side spoilers that angle outward to deflect passing air away from the rear axle's wheels.
Trains may use spoilers to induce drag (like an air brake). A prototype
Japanese high-speed train, the
Fastech 360
Fastech 360 is the name given to a pair of former experimental high-speed EMU trainsets developed by East Japan Railway Company (JR East) to test technology for the next-generation Shinkansen rolling stock. The name is a portmanteau of Fast, Techn ...
, is designed to reach speeds of . Its nose is specifically designed to spoil a wind effect associated with passing through tunnels, and it can deploy 'ears' that act to slow the train in case of emergency by increasing its drag.
Some modern race cars employ a passive situational spoiler called a
roof flap
A roof flap is an aerodynamic feature on race cars, mainly stock cars, which functions as an emergency spoiler to prevent the vehicle from lifting off the ground. The flaps are stowed during normal vehicle operation; however, in certain situation ...
. The body of the car is designed to generate downforce while driving forward. These roof flaps deploy when the body of the car is rotated so it is traveling in reverse, a condition where the body instead generates lift. The roof flaps deploy because they are recessed into a pocket in the roof. The low pressure above this pocket will cause the flaps to deploy, and counteract some of the lift generated by the car, making it more resistant to coming out of contact with the ground. These devices were introduced in 1994 in
NASCAR
The National Association for Stock Car Auto Racing, LLC (NASCAR) is an American auto racing sanctioning and operating company that is best known for stock car racing. The privately owned company was founded by Bill France Sr. in 1948, and hi ...
following
Rusty Wallace's crash at
Talladega.
Whale tail
![Porsche Carrera hl white](https://upload.wikimedia.org/wikipedia/commons/4/4f/Porsche_Carrera_hl_white.jpg)
When the
Porsche 911 Turbo
The Porsche 911 (pronounced ''Nine Eleven'' or in german: Neunelfer) is a two-door 2+2 high performance rear-engined sports car introduced in September 1964 by Porsche AG of Stuttgart, Germany. It has a rear-mounted flat-six engine and ori ...
debuted in August 1974, with large, flared, rear spoilers, they were immediately dubbed whale tails.
Designed to reduce rear-end lift and so keep the car from
oversteer
Understeer and oversteer are vehicle dynamics terms used to describe the sensitivity of a vehicle to steering. Oversteer is what occurs when a car turns (steers) by more than the amount commanded by the driver. Conversely, understeer is what occ ...
ing at high speeds, the rubber edges of the whale tail spoilers were thought to be "pedestrian friendly". The Turbo with its whale tail was popular. It also became one of the world's most recognizable sports cars,
remaining in production for the next two decades in one form or another, with more than 23,000 sold by 1989. From 1978, the rear spoiler was redesigned and dubbed 'teatray' on account of its raised sides.
The
Porsche 911
The Porsche 911 (pronounced ''Nine Eleven'' or in german: Neunelfer) is a two-door 2+2 high performance rear-engined sports car introduced in September 1964 by Porsche AG of Stuttgart, Germany. It has a rear-mounted flat-six engine and origin ...
whale tails were used in conjunction with a chin spoiler attached to the front valence panel, which, according to some sources, did not enhance
aerodynamic
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
stability.
It has been found to be less effective in multiplying
downforce
Downforce is a downwards lift force created by the aerodynamic features of a vehicle. If the vehicle is a car, the purpose of downforce is to allow the car to travel faster by increasing the vertical force on the tires, thus creating more grip. ...
than newer technologies like an
airfoil
An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine.
...
, "rear wing running across the base of the tailgate window", or "an electronically controlled wing that deploys at about 50 mph" (80 km/h).
History
![Porsche Carrera RS white - blue](https://upload.wikimedia.org/wikipedia/commons/f/fd/Porsche_Carrera_RS_white_-_blue.jpg)
The whale tail came on the heels of the 1973 "duck tail" or ''Bürzel'' in German (as a part of the
E-program), a smaller and less flared rear-spoiler fitted to 911 Carrera RS (meaning ''Rennsport'' or race sport in German), optional outside Germany.
[ The whaletail was originally designed for ]Porsche 930
The Porsche 930 is a sports car manufactured by German automobile manufacturer Porsche between 1975 and 1989, known to the public as the 911 Turbo. It was the maker's top-of-the-range 911 model for its entire production duration and, at the ti ...
and Porsche 935
The Porsche 935 was a race car developed and manufactured by German automaker Porsche. Introduced in 1976 as the factory racing version of the Porsche 930, 911 (930) Turbo and prepared for Fédération Internationale de l'Automobile, FIA-Group 5 ( ...
race cars in 1973, and introduced to the Turbo in 1974 (as a part of the H-program); it was also an option on non-turbo Carreras from 1975. Both types of spoilers were designed while Dr. Ernst Fuhrmann was serving as the Technical Director of Porsche AG
Dr. Ing. h.c. F. Porsche AG, usually shortened to Porsche (; see #Pronunciation, below), is a German automobile manufacturer specializing in high-performance sports cars, SUVs and sedans, headquartered in Stuttgart, Baden-Württemberg, Germany ...
. In 1976, a rubber front chin spoiler was also introduced to offset the more effective spoiler.[ By 1978, Porsche introduced another design for the rear spoiler, the "teatray", a boxier enclosure which accommodated the intercooler, and was also an option for the 911SC.][
]
Other vehicles
The whale tail car spoilers of the Porsche 911 caught on as a fashion statement, and the term has been used to refer to large rear spoilers on a number of automobiles, including Ford Sierra RS, Focus
Focus, or its plural form foci may refer to:
Arts
* Focus or Focus Festival, former name of the Adelaide Fringe arts festival in South Australia Film
*''Focus'', a 1962 TV film starring James Whitmore
* ''Focus'' (2001 film), a 2001 film based ...
, Chevrolet Camaro
The Chevrolet Camaro is a mid-size American automobile manufactured by Chevrolet, classified as a pony car. It first went on sale on September 29, 1966, for the 1967 model year and was designed to compete with the Ford Mustang. The Camaro ...
, and Saab 900
The Saab 900 is a mid-sized automobile which was produced by Saab from 1978 until 1998 in two generations; the first from 1978 to 1993, and the second from 1994 to 1998.
The first-generation car was based on the Saab 99 chassis, though with a ...
. Whale tail spoilers also appear at the rear of tricycle
A tricycle, sometimes abbreviated to trike, is a human-powered (or gasoline or electric motor powered or assisted, or gravity powered) three-wheeled vehicle.
Some tricycles, such as cycle rickshaws (for passenger transport) and freight trikes ...
s, trucks, boats, and other vehicles.
Gallery
File:1987 ford sierra rs500.jpg, This Ford Sierra RS Cosworth
The Ford Sierra RS Cosworth is a high-performance version of the Ford Sierra that was built by Ford Europe from 1986 to 1992. It was the result of a Ford Motorsport project with the purpose of producing an outright winner for Group A racing in ...
has a factory-installed rear spoiler
File:Mitsubishi Lancer Evolution aftermarket spoiler.JPG, Mitsubishi Lancer Evolution
The Mitsubishi Lancer Evolution, popularly referred to as the 'Evo', is a sports sedan and rally car based on the Lancer that was manufactured by Japanese manufacturer Mitsubishi Motors from 1992 until 2016. There have been ten official versio ...
spoiler
File:Mercedes CLK GTR Crop.jpg, Mercedes-Benz CLK GTR
The Mercedes-Benz CLK GTR (C297) is a GT1 sports car built and produced by Mercedes-Benz in conjunction with their then motorsport partner AMG. Intended for racing in the new FIA GT Championship series in 1997, the CLK GTR was designed primar ...
File:Porsche GT3 at Europort (9293407781).jpg, Porsche 996 GT3
The Porsche 911 GT3 is a high-performance homologation model of the Porsche 911 sports car. It is a line of high-performance models, which began with the 1973 911 Carrera RS.
The GT3 has had a successful racing career in the one-make national ...
File:Bugatti veyron2.jpg, Retractable Spoiler on a Bugatti Veyron
File:Kurt Busch 2008 Miller Lite Dodge Charger.jpg, NASCAR Dodge Charger
See also
* Aerofoil
An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine.
...
* Car tailfin
* Diffuser
Diffuser may refer to:
Aerodynamics
* Diffuser (automotive), a shaped section of a car's underbody which improves the car's aerodynamic properties
* Part of a jet engine air intake, especially when operated at supersonic speeds
* The channel bet ...
* Gurney flap
The Gurney flap (or wickerbill) is a small tab projecting from the trailing edge of a wing. Typically it is set at a right angle to the pressure-side surface of the airfoil
and projects 1% to 2% of the wing chord.
This trailing edge device can i ...
References
{{DEFAULTSORT:Spoiler (Automotive)
Automotive accessories
Automotive body parts
Automotive styling features
Automotive technologies
Motorsport terminology
German inventions