Go-Kart

Go-Kart
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Go-Kart".

For other meanings see kart (disambiguation)

2006 World Champion Davide Fore demonstrates the KF1

Zanardi chassis and KF1 at the Paul Ricard in Feb. 2007

Kart racing or karting is a variant of open-wheel motor sport with simple, small 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 and more expensive ranks of motorsports.

Karts vary in speed and some (known as Superkarts) can reach speeds exceeding 160 mph (250 km/h).^[1] A KF1 kart, with a 125 cc 2-stroke engine and an overall weight including the driver of 150 kilograms has a top speed of 85 mph (140 km/h). It takes a little more than 3 seconds to go from 0 to 60 mph with a 125 cc shifter kart (6 gears), with a top speed of 115 mph (185 km/h) on long circuits.^[2]

content

1 History
2 Components
3 Racing
- 3.1 Racing formats
- 3.2 Racing categories
  - 3.2.1 International
  - 3.2.2 National
4 Karting as a learning tool
- 4.1 Concession karts
5 Notes
6 See also
7 External links

History

1960 Speedcar, a predecessor to karting in Sweden

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.^[3] Karting has rapidly spread to other countries,^[4] and currently has a large following in Europe.

The first kart manufacturer was an American company, Go Kart Manufacturing Co. (1958). McCulloch was the first company, in 1959, to produce engines for karts. Its first engine, the McCulloch MC-10, was an adapted chainsaw 2-stroke engine^[5]. Later, in the 1960's, motorcycle engines were also adapted for kart use, before dedicated manufacturers, especially in Italy (IAME), started to build engines for the sport.

Components

Chassis

New 2007 KF engines

The chassis are made of steel tube.^[6]^[7] 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 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. 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 increasingly popular; however, certain classes do not allow them.

Professionally raced karts typically weigh 165 to 175 lb (75 to 80 kg), complete without driver. Avanti Kart, Parolin, Tony Kart, Maranello, Trulli, Biesse, Birel, CRG, Haase, Sodikart, Gillard, Top Kart, Intrepid, Kosmic, Zanardi, FA Kart, and Swiss Hutless are a few well known examples of the many European manufacturers of race-quality chassis. American companies in the shifter kart market include: GT Race Karts, Trackmagic, Shockwave Karting and Margay. Australia produce the Arrow brand.

Engines

Racing karts use small 2-stroke or 4-stroke engines.

2-stroke kart engines are developed and built by dedicated manufacturers. Comer, IAME (Parilla, Komet), TM, Vortex, Titan, REFO, Yamaha and Rotax are manufacturers of such engines. These can develop from about 4 hp to 7 hp for a single-cylinder 60 cc unit to 90 hp for a twin 250 cc.^[1] The most popular categories worldwide are those using the Touch-and-go (TAG) 125 cc units. 100 cc 2-stroke kart engines can run in excess of 19,000 rpm while the new 125 cc KF1 engines are electronically limited at 16,000 rpm.^[8] Most are water-cooled today; however, previously air-cooled engines dominated the sport.

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 plenty adequate for racing and fun kart applications. There are also more powerful four-stroke options available from manufacturers like Yamaha, TKM, Biland 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.

Listen to 2-stroke kart engines - recorded at the 2006 World Championship in Angerville - France

Transmission

Karts do not have a differential.^[7]^[9] The lack of a differential means that one rear tire must slide while cornering; this is achieved by designing the chassis so that the inside rear tire lifts up slightly when the kart turns the corner. This allows the tire to lose some of its grip and slide or lift off the ground completely.

Power is transmitted from the engine to the rear axle by way of a chain. Both engine and axle sprockets are removable, their ratio has to be adapted according to track configuration in order to get the most of the engine.

In the early days, karts were direct drive only, but the inconvenience of that setup soon led to the centrifugal clutch for the club level classes. Dry centrifugal clutches are now used in many categories (Rotax Max is one example) and have become the norm as the top international classes have switched to 125 cc clutched engines as of January 2007.

Tires

Wheels and tires are much smaller than those used on a normal car. Wheels are made of magnesium alloy or aluminum. Similar to other motorsports, kart tires have different types for use appropriate to track conditions:

Slicks for dry weather. In international level racing these are some of the softest and most advanced tires in motorsport. Some car tire manufacturers, such as Bridgestone and Dunlop, make tires for karts; there are also specific Kart tire manufacturers, for example MG, MOJO, and Vega. Kart tires come in many different compounds, from very soft to very hard.
Rain tires or wets for wet weather
Intermediates for damp or low traction conditions. Sometimes worn rain tires are used.
Special, such as spiked tire for icy conditions, or cuts for high grip dirt/clay speedways. Cuts are modified slicks using a lathe to optimize handling while spiked tires are slicks with screws through them.

Tires are sometimes prepared with special solvents to soften them and increase grip, however this is banned by many racing organizations. These solvents typically affect the behavior of the tire temporarily and are most often destructive to the rubber. The tires can support cornering forces in excess of 2 G (20 m/s²), depending on chassis, engine, and motor setup.

Racing

Sprint race at Granja Viana, Brazil

Kart racing is generally accepted as the most economic form of motorsport available. As a free-time activity, it can be performed by almost anybody, and as a motorsport in itself, it is one of the sports regulated by FIA (under the name of CIK), permitting licensed racing for anyone from the age of 8 onward.

In the USA there is not as much FIA involvement, instead many organizations regulate racing, such as the IKF (International Kart Federation), WKA (World Karting Association), IRA (International Racing Association), KART (Karter's of America Racing Triad), and the more recent Stars of Karting presented by the Indy Racing League.

In the UK the MSA (Motor Sports Association) regulate Karting. Some associations, such as NatSKA (National Schools Karting Association), organize race meetings throughout the country under the authority of the MSA.

A variety of kart circuits permit the sport to be practiced, although only homologated tracks can have official races in Europe (see Kart circuits).

Racing classes start at age 7 or 8 (5 in the US with "Kid Karts") and generally run in 3-year age groupings or weight divisions until “senior” status is reached at age 15 or 16, depending on the series.

Racing formats

Typically, race formats are one of the following:

Sprint

Sprint racing takes place on dedicated kart circuits resembling small road courses, with left and right turns. Tracks go from 1/4 mile (400 m) to over 1 mile (1,600 meters) in length.

The sprint format is a series of short-duration races, normally for a small number of laps, that qualify for a final, with a variety of point scoring calculations to determine the event's overall winner. Typical duration does not normally exceed 15 minutes. Here, speed and successful passing is of the most importance. It normally occurs in the format of three qualifying heats and a final race for trophy positions.

The FIA championships, including the Karting World Championship, take place in this format.

Endurance

Laydown Enduros at Daytona, USA

Endurance races last for an extended period, from 30 minutes up to 24 hours or more, for one or more drivers. In general, consistency, reliability, and pit strategy is of greater importance than all out speed.

Called "Enduro" racing in the USA, most WKA & IKF sanctioned events typically last 30 minutes (Sprint Enduro) or 45 minutes (Laydown Enduro) and are run continuous without pit stops. Enduro events are held on full-size road racing circuits that are usually between 1.5 & 4 miles in length.

As well as the famous 24 Hours of Le Mans race for automobiles there is also a 24 hours event for karts which takes place at the kart circuit Alain Prost at Le Mans, France.^[10] This race has taken place since 1986 and its winners list include Sébastien Bourdais (in 1996), four times Champ Car champion and current Formula 1 driver with Toro Rosso.

Speedway

Speedway racing takes place on asphalt or clay oval tracks which are normally between 1/6 mile and 1/4 mile long. Tracks primarily consist of two straight and four left-turn corners, few tracks are symmetric and often the shape parallels that of an egg or a tri-oval.

'Offset' kart chassis have been developed for precise handling and adjustability in left-turn-only racing competition taking place on oval and tri-oval tracks.

Speedway kart races range in length from 4 laps for a trophy dash, to 20 laps for a main event.

The two chief racing formats used in dirt speedway karting are heat races and timed laps qualification :

The International Kart Federation (IKF) runs a racing format of two 10 lap heats followed by a 20 lap final. Finishing positions in the two heat races are used to calculate the starting position in the feature race.

The World Karting Association (WKA) uses time qualifying. Karts equipped with transponders are sent out onto the track in groups of 5 or less to try to achieve the fastest lap time. Positions for the 20 laps feature event are determined by qualifying time.

The American Kart Racing Association (AKRA) uses group transponder qualifying to calculate starting positions for 20-lap features.

Racing categories

There are many different classes or formula in karting.

International

The CIK-FIA sanctions international championships in KF1, KF2, KF3, KZ1, KZ2 and Superkart. These are regarded as the top level classes of karting and are also raced in national championships worldwide. The World Championship (KF1) is decided here, the current 2007 World Champion is Marco Ardigo from Italy.^[11]

CIK-FIA categories are:

KF1 (previously named Formula A or FA) which is the top level, KF2 (previously named Intercontinental A or ICA), KF3 (previously named ICA-Junior, ICA-J or JICA), and KF4 (so-called “basic” category). All are using the same water-cooled no-gearbox 125 cc “long life” two-stroke engines with starter and clutch, each with different technical specifications (mufflers, air boxes, carburetor, rev limit etc...).
KZ1 and KZ2 are the 125 cc gearbox categories (previously named Super-ICC and ICC respectively).
Superkart is a 250 cc gearbox category.

National

In the UK, the most celebrated karting series is the National karting series, also known as Super 1. There are three types of Super 1 championships:

MSA series : Formula A, ICA, Junior ICA, Formula 100 and Formula Cadet
Rotax series : Minimax, Junior Max, Senior Max, Senior Max 177 and Rotax DD2
TKM series : Formula Junior TKM, Formula Junior Intermediate, Formula TKM Extreme, TKM Junior and Senior 4-stroke and since 2006, Honda Cadet

NatSKA is a budget karting association set up for schools and youth groups in the UK, with 13 classes.

In the United States, the biggest proportion of racers are in the dirt oval classes which often use Briggs & Stratton industrial engines. This style of racing is prominent in the Southeast and Midwest. In the West, European style sprint racing is much more common.

In Australia, classes include Midget, Rookie, Junior and Senior.

Many people race worldwide in Spec series such as Rotax Max (a Touch-and-Go class) or those using the Yamaha KT100 engine.

Karting as a learning tool

Kart racing is usually used as a low-cost and relatively safe way to introduce drivers to motor racing. Many people associate it with young drivers but adults are also very active in karting. Karting is considered the first step in any serious racer's career. It can prepare the driver for high-speed wheel-to-wheel racing by helping develop quick reflexes, precision car control, and decision-making skills. In addition, it brings an awareness of the various parameters that can be altered to try to improve the competitiveness of the kart (examples being tire pressure, gearing, seat position, chassis stiffness) that also exist in other forms of motor racing.

All current as well as many former Formula One racers grew up racing karts, most prominent among them Michael Schumacher, Ayrton Senna, Alain Prost, Fernando Alonso, Kimi Räikkönen and Lewis Hamilton. Many NASCAR drivers also got their start in racing from karts, such as Darrell Waltrip, Lake Speed, Ricky Rudd, Juan Pablo Montoya, Tony Stewart, and Jeff Gordon.

Concession karts

As well as "serious" competitive kart racing, many commercial enterprises offer casual hire of karts known as "Concession" karts. Such karts are usually powered by small, detuned four-stroke engines and are far slower than the fully-fledged competitive versions. These karts are built and set to be drivable by anyone. Some tracks also offer racing capable rental karts, also known as "Arrive and Drive" style karts.