Kart racing or karting is a variant of open-wheel motorsport with small, open, four-wheeled vehicles called karts, go-karts, or gearbox/shifter karts depending on the design. They are usually raced on scaled-down circuits. Karting is commonly perceived as the stepping stone to the higher ranks of motorsports.
Karts vary widely in speed and some (known as Superkarts) can reach speeds exceeding 260 kilometres per hour (160 mph), while amusement park go-karts intended for the general public may be limited to speeds of no more than 25 kilometres per hour (16 mph).
American Art Ingels is generally accepted to be the father of karting. A veteran hot rodder and a race car builder at Kurtis Kraft, he built the first kart in Southern California in 1956. Instantly popular, Karting rapidly spread to other countries, and currently has a large following in Europe.
The first kart manufacturer was an American company, Go Kart Manufacturing Co. (1958). In 1959, McCulloch was the first company, to produce engines for karts. Its first engine, the McCulloch MC-10, was an adapted chainsaw 2-stroke engine. Later, in the 1960s, motorcycle engines were also adapted for kart use, before dedicated manufacturers, especially in Italy (IAME), started to build engines for the sport.
The chassis are made of steel tubing. There is no suspension, therefore chassis have to be flexible enough to work as a suspension and stiff enough not to break or give way on a turn. Kart chassis are classified in the USA as ‘Open’, ‘Caged’, ‘Straight’ or ‘Offset’. All Commission Internationale de Karting – Fédération Internationale de l’Automobile or CIK-FIA approved chassis are ‘Straight’ and ‘Open’.
Open karts have no roll cage.
Caged karts have a roll cage surrounding the driver; they are mostly used on dirt tracks.
In Straight chassis the driver sits in the center. Straight chassis are used for sprint racing.
In Offset chassis the driver sits on the left side. Offset chassis are used for left-turn-only speedway racing.
The stiffness of the chassis enables different handling characteristics for different circumstances. Typically, for dry conditions a stiffer chassis is preferable, while in wet or other poor traction conditions, a more flexible chassis may work better. The best chassis allow for stiffening bars at the rear, front and side to be added or removed according to race conditions.
Braking is achieved by a disc brake mounted on the rear axle. Front disc brakes are used in most shifter kart classes and are increasingly popular in other classes; however, certain classes do not allow them. Shifter karts have dual master cylinders, one for the front and one for the rear and are adjustable to allow for front/ rear bias changes.
Professionally raced karts typically weigh 165 to 175 lb (75 to 79 kg), complete without driver. Avanti, Tony Kart, Trulli, Birel, CRG, Gillard, Intrepid, Kosmic, Zanardi or FA Kart are a few well known examples of the many European manufacturers of race-quality chassis. Emmick, Coyote, Bandit, Shadow, MGM, PRC and Margay are American companies producing kart chassis.
Amusement park go-karts can be powered by 4-stroke engines or electric motors, while racing karts use small 2-stroke or 4-stroke engines.
4-stroke engines can be standard air-cooled industrial based engines, sometimes with small modifications, developing from about 5 to 20 hp. Briggs & Stratton, Tecumseh, Kohler, Robin, and Honda are manufacturers of such engines. They are adequate for racing and fun kart applications. There are also more powerful four-stroke engines available from manufacturers like Yamaha, TKM, Swissauto or Aixro (Wankel engine) offering from 15 hp up to 48 hp. They run to and around 11,000 rpm, and are manufactured specifically for karting. Those are used in some National Championship classes like the two-strokes.
2-stroke kart engines are developed and built by dedicated manufacturers. WTP, Comer, IAME (Parilla, Komet), TM, Vortex, Titan, REFO, TKM, PRD, Yamaha and Rotax are manufacturers of such engines. These can develop from about 8 hp for a single-cylinder 60 cc unit (MiniROK by Vortex) to over 90 hp for a twin 250 cc. Today, the most popular categories worldwide are those using the TaG 125 cc units. The recent 125 cc KF1 engines are electronically limited at 16,000 rpm.
Superkart is a form of motor racing in which the class is a racing vehicle sized like a kart but with several characteristics more strongly associated with open-wheel racing cars.
The most obvious difference between a Superkart and any other form of kart is that they have full aerodynamic bodykits and can race on car circuits over 1,500 metres in length. The power unit, most often, but not exclusively two stroke 250 cc engines, can be specially designed kart engines or production motorcycle engines with either five or six-speed sequential gearboxes. Owing to their high top speed and superb cornering ability, a Superkart’s aerodynamic bodywork includes a front fairing, larger sidepods, and a rear wing. They use either 5-or-6-inch-diameter (130 or 150 mm) tires and wheels and most often race on full size auto-racing circuits.
250 cc Superkarts often[quantify] set faster lap times than much more expensive and technically advanced racing machines. Some British and Australian classes also include 125 cc gearbox karts.
Superkarts race on “long circuits” (e.g. Silverstone, Laguna Seca, Magny-Cours). In the UK they also race on “short circuits” (e.g. Kimbolton), “short circuits” are under 1,500 metres in length.
Superkarts are raced worldwide. There is a multi-event CIK-FIA European Superkart Championship (for 250 cc karts only), and there has in the past been a World Championship, which was last run in 1995.
Powered by a 2-stroke 250 cc engine producing 62 hp for an overall weight including the driver of 205 kilograms, Superkarts have a power/weight ratio of 440 hp/tonne (330 W/kg)(c.5 lbs/hp). Superkarts can accelerate from 0 to 60 mph in less than 3 seconds with a top speed of 155 mph (250 km/h). Their low weight and good downforce make for excellent cornering and braking abilities. A Superkart is capable of braking from 100 mph (160 km/h) to standstill in around 2 seconds, and taking corners at nearly 3 g (30 m/s²).
At some circuits, Superkarts are the outright lap-record holders, at others they run at around Formula 3 lap times.
Ben Wilshire British 125 Open class Superkart
British Superkart Divisions :
Main article: British Superkart Championship
Division 1 is open to 250 cc karts with one or two cylinders and five or six speed gearboxes. Typically the karts produce 100 hp and are capable of 160 mph – the fastest form of kart. This formula was previously known as Formula E.
Division 2 is for single cylinder karts with 5 and 6-speed boxes. Typically these karts produce 65 hp and are capable of 140 mph. However, being lighter than the twin cylinder (Division 1) karts they can be as quick on twisted circuits. This formula was previously known as 250 International. However the main British series is for single cylinder 250 cc karts with 5-speed only, also known as 250 National.
125 Open – Powered by 125 cc engines and again featuring 6-speed sequential gearboxes, this sprint kart class uses lighter chassis than the 250’s.
125 ICC (KZ) – Powered by similar 6-speed 125 cc engines to the 125 Open class with tighter tuning restrictions, this CIK sprint kart class hosts some of the closest Superkart racing in the UK.
2007 Australian 250 cc International champion Warren McIlveen (Stockman-Honda)
Australian Superkart Classes:
Main article: Australian Superkart Championship
Superkarting in Australia has, since 1989, referred to any form of racing kart to race on full-size motor racing circuits, usually as sanctioned by the Australian ASN, CAMS.
250 cc International – commonly referred to as twins or inters, these karts are powered by twin cylinder engines and usually have 6-speed sequential gearboxes. Several European and North American chassis are popular in addition to locally developed designs.
250 cc National – single cylinder class, the 250 National class is powered by 250 cc motocross engines and also feature 6-speed sequential gearboxes.
125 cc Gearbox – most often powered by 125 cc Honda and Yamaha Grand Prix motorcycle engines equipped with six speed sequential gearboxes, this Superkart class uses mostly the same chassis as the 250 classes. They run at lighter weights than the 250 classes, which makes for close racing with mid-field 250 Nationals at some circuits.