Open-wheel car

Anopen-wheel caris a car with the wheels outside the car's main body, and usually having only one seat. Open-wheel cars contrast with street cars,sports cars,stock cars,andtouring cars,which have their wheels below the body or insidefenders.Open-wheel cars are built both forroad racingandoval track racing.Open-wheel cars licensed for use on public roads (street legal), such as theAriel Atom,are uncommon, as they are often impractical for everyday use.

Open-wheel car
2023Formula One car,McLaren MCL60,driven byLando Norris
Classification	Vehicle
Application	Recreation,sports
Fuel source	Gasoline,electric,hydrogen
Powered	Yes
Self-propelled	Yes
Wheels	4–6
Aerofoils	Optional
Axles	2–4
Inventor	Ray Harroun

History

American racecar driver and constructorRay Harrounwas an early pioneer of the concept of a lightweight single-seater, open-wheel "monoposto" racecar.After working as a mechanic in the automotive industry, Harroun began competitive professional racing in 1906, winning theAAA National Championshipin 1910. He was then hired by theMarmon Motor Car Companyas chief engineer, charged with building a racecar intended to race at the firstIndianapolis 500,which he went on to win. He developed a revolutionary concept which would become the originator and forefather of the single-seater (i.e. monoposto) racecar design.Harroun has also been credited by some as pioneering the rear-view mirror which appeared on his1911 Indianapolis 500winning car, though he himself claimed he got the idea from seeing a mirror used for a similar purpose on ahorse-drawn vehiclein 1904.

AFord Model T,one of the most popular road-legal cars of the early 20th century. Note how the wheels are well outside the main body of the car, as was typical for the era.

Prior toWorld War II,street automobiles generally had wheels that protruded beyond the vehicle's main body, though they were typically covered withmudguardsto protect the car body and following traffic from water and mud spray. With the advent ofunibodyvehicle construction, the desire to maximise interior space, to improve aerodynamics, and aircraft-inspired styling trends of the era, by the end of the 1950s the majority of new road-registerable vehicles had wheels that were under the main body of the car, and thus the open-wheel design became almost exclusively associated with racing vehicles.

A 1954Mercedes-Benz 300 SLwhich featured wheels under the main body of the vehicle, primarily for aerodynamic drag reduction

Formula Onecars have almost exclusively used the open-wheel design throughout the history of the championship. The only notable exception was the "Monza body" variation of theMercedes-Benz W196racer of 1954–55, which covered the wheels with bodywork for aerodynamic reasons. Modern Formula One regulations mandate the open-wheel configuration.

Design

A typical open-wheeler has a minimal cockpit, sufficient only to enclose the driver's body, with the head exposed to the air. In theWhelen Modified Tourand other short track modified series, the driver's head is contained in the car. In modern cars, the engine is often located directly behind the driver and drives the rear wheels; except inasphalt modifiedcars, such as the Whelen Modified Tour, where the engine is in front of the driver. Depending on the rules of the class, many types of open-wheelers havewingsat the front and rear of the vehicle, as well as a very low and virtually flatundertraythat helps achieve additional aerodynamicdownforcepushing the car onto the road. While many other categories of racing cars produce downforce, the top categories of open-wheel racing cars (particularly Formula One andIndyCar) produce far more downforce relative to their mass than any other racing category, allowing much higher corner speeds on comparable tracks. However, this is not always the case; some open-wheel categories raced primarily as development or amateur categories, such asFormula FordorFormula Vee,do not permit the use of wings or ground effect aerodynamics.

Some major races, such as theSingapore Grand Prix,Monaco Grand Prix(sanctioned by Formula One) and theLong Beach Grand Prix(sanctioned by IndyCar), are held on temporarystreet circuits.However, most open-wheel races are on dedicatedroad courses,such asWatkins Glenin the US,Nürburgringin Germany,Spa-Francorchampsin Belgium andSilverstonein Great Britain. In the United States, some top-level open-wheel events are held on ovals, of both short track and superspeedway variety, with emphasis more on speed and endurance than the maneuverability required for road and street course events. The Whelen Modified Tour is the only opened wheeled race car series endorsed byNASCAR.This series races on most of NASCAR's most famous tracks in the United States. Other asphalt modified series race on short tracks in the United States and Canada, such asWyoming County International Speedwayin New York. The best-attended oval race in the world is the annual Indianapolis 500 (Indy 500) inSpeedway, Indiana,sanctioned by IndyCar; in the United States it is quite common to refer to open-wheel cars as IndyCars, because of their recognizable appearance and widespread popularity across America at the Indy 500. Compared to covered-wheel race cars, open-wheeled cars allow more precise placement of the front wheels on the race course, as the tires are clearly visible to the driver. This allows the maximum potential of the cars to be achieved during cornering and passing. Furthermore, open-wheeled cars are less tolerant of vehicle-to-vehicle contact, which usually results in vehicle damage and retiring, whereas some level of contact is expected in covered-wheel racing, as for example in NASCAR. Open-wheeled drivers must be extremely precise to avoid contact.

Regulations tend to permit much lower open-wheel car weights than in categories that more closely resemble street-legal vehicles, such assports,touring,andstock cars.For instance, a Formula One car must weigh at least 798 kilograms (1,759 lb);the minimum weight for NASCAR is 1,500 kilograms (3,200 lb).

Driving

Open-wheeled racing is among the fastest in the world. Formula One cars can reach speeds in excess of 360 kilometres per hour (220 mph). AtAutodromo Nazionale Monza,Antônio Pizzoniaof BMW Williams F1 team recorded a top speed of 369.9 kilometres per hour (229.8 mph) (over 102 m/s) in the2004 Italian Grand Prix.Since the end of theV10era in 2006, such high speeds have not been reached, with later vehicles reaching around 360 kilometres per hour (220 mph).It is difficult to give precise figures for the absolute top speeds of Formula One cars as the data are not generally released by teams. The 'speed traps' on fast circuits such as Monza give a good indication, but are not necessarily located at the point on the track where the car is travelling at its fastest.BAR Hondateam recorded an average top speed of 400 kilometres per hour (250 mph) in 2006 atBonneville Salt Flats,with unofficial top speed reaching 413 kilometres per hour (257 mph) using their modifiedBAR 007Formula One car. Speeds on ovals can range in constant excess of 210–220 miles per hour (340–350 km/h), and atIndianapolisin excess of 230 miles per hour (370 km/h). In 2000,Gil de Ferranset the one-lap qualifying record of 241.428 miles per hour (388.541 km/h) atCalifornia Speedway.Even on tight non-oval street circuits such as theGrand Prix of Toronto,open-wheelIndy Carsattain speeds of 190 miles per hour (310 km/h).

Regardless of top speeds, Formula One open-wheel race cars hold the outright lap record at the circuits where they race due to their combination of top speed, acceleration, and cornering abilities. For example, at theMonza Circuitthe fastest lap in the 2021 Grand Prix (Daniel Ricciardo1:24.812) is more than six seconds per lap faster than the fastest closed-wheel racing car, anLMP1sports car,and more than 20 seconds per lap faster than theDTMtouring car lap record.

Driving an open-wheel car is substantially different from driving a car with fenders. Virtually all Formula One and IndyCar drivers spend some time in various open-wheel categories before joining either top series. Open-wheel vehicles, due to their light weight,aerodynamiccapabilities, and powerful engines, are often considered the fastest racing vehicles available and among the most challenging to master. Wheel-to-wheel contact is dangerous, particularly when the forward edge of one tire contacts the rear of another tire: since the treads are moving in opposite directions (one upward, one downward) at the point of contact, both wheels rapidly decelerate, torquing the chassis of both cars and often causing one or both vehicles to be suddenly and powerfully flung upwards (the rear car tends to pitch forward, and the front car tends to pitch backward.) An example of this is the 2005Chicagolandcrash ofRyan BriscoeandAlex Barron.

Advantages

The lower weight of an open-wheel racecar enables better performance. While the exposure of the wheels to the airstream causes a very high aerodynamicdragat high speeds, it allows improved cooling of the brakes, which is important on road courses with their frequent changes of pace.

Gallery

• 
  Caterham open wheeled sports car, derived from Lotus 7
• 
  ElectricFormula Eracing car (Spark SRT05e) racing forHWA Racelab
• 
  2023Red Bull Racing RB19,driven byMax Verstappen
• 
  1994 Penske Indy Car
• 
  Ariel Atomsports car from UK
• 
  KTM X-Bow,road legal open wheeled sportscar
• 
  Asphalt Modified Short Track Race Car
• 
  Sprint cars
• 
  ABarlottigo-kart:a low-end open-wheel car
• 
  Nigel Mansellin aCARTcar at Mid-Ohio Sports Car Course, 1993

Safety

In 2018, several single seater series such as Formula One,Formula 2(with their newDallara F2 2018chassis), and Formula E (with their new Spark SRT05e chassis) introduced a protection system to the cockpit called the"halo",a wishbone-shaped frame aimed to deflect debris away from a driver's head. Despite initial criticism, including for the reason of obstructing the driver's vision, it gained some praise in theFormula 2 sprint race in CatalunyawhenNirei Fukuzumispun and had the back of his car land on fellow countrymanTadasuke Makino's halo. In the 2018Formula 1 Belgian Grand Prix,McLarendriverFernando Alonsowas sent airborne after being hit from behind by theRenaultofNico Hülkenbergand struck the halo ofSauberdriverCharles Leclerc,thereby saving the Monegasque driver from a visor strike.

In2019,the newly-formedFIA Formula 3 Championshipintroduced a halo to their new chassis which was unveiled at the2018 Abu Dhabi Grand Prix.

In2020,theIndyCar Seriesadopted a halo combined with an aeroscreen, built by Red Bull Advanced Technologies.

At the start of the 2020Bahrain Grand Prix,Romain Grosjeancollided withDaniil Kvyatin which his car broke in two and burst into flames as it split the barrier. The halo helped prevent Grosjean from possible decapitation while it allowed him to escape from the fire.