Kart racing

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 and more expensive ranks of motorsports.

Karts vary widely in speed and some (known as Superkarts) can reach speeds exceeding 260 km/h, while go-karts intended for the general public in amusement parks may be limited to speeds of no more than 25 km/h. 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 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 185 km/h on long circuits. Kart racing is available for just about any age with different classes. 5-7 year olds can enter in karts that top out at about 30 MPH. 7-11 year olds go a step up with karts reaching speeds of about 80 km/h. 12-15 year olds are put in full sized karts with 100cc-125cc engines that will reach about 125 km/h. The next classes up all have about the same top speed with different variations to cope with added weight for older people. A single geared, 125cc, 2 stroke kart will do 0-60 in about 4-5 seconds and pull 3-4 g's through the corners. Shifter karts (karts with multiple gears), accelerate much quicker, however, have worse handling going into the corners because of added weight, and worse weight balance, however, can quickly pull out of the corners with the added power. Shifter karts also have 4 brakes, instead of the normal 1, on the single speed karts. Lap times differ by about 2-5 seconds due to the shifter karts advantages.

History
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. Karting has 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). 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. 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.

Chassis
The chassis are made of steel tube. 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. 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 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, 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 and Margay are American companies producing kart chassis.

Engines
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. Most are water-cooled today; however, previously air-cooled engines dominated the sport.

Transmission
Karts do not have a differential. 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 from the engine.

In the early days, karts were direct drive only (requiring push starts), 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. Rims are made of magnesium alloy or aluminum. Tires can support cornering forces in excess of 2 'g' (20 m/s²), depending on chassis, engine, and motor setup.

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, Dunlop or Maxxis, make tires for karts. There are also specific kart tire manufacturers, which include MG, MOJO, and Vega. Slick kart tires come in many different compounds, from very soft (maximum grip) to very hard (amusement and rental karts, less grip but long life span).
 * Rain tires, or "wets", for wet weather. They are grooved, made of soft compound, and are narrower than slicks. Not all racing classes allow rain tires.
 * Special, such as spiked tires for icy conditions, or "cuts" for high grip dirt/clay speedways. Cuts are slicks modified with a lathe to optimize handling.

Data acquisition
As in other motor sports, several data acquisition systems have been developed for kart racing. These systems allow the driver to monitor from a display fixed on the steering wheel some parameters such as RPM, timing of laps (including sectors), number of laps, best lap, cooling system temperature, exhaust gas temperature and sometimes speed or even gear for shifter karts.

Some of those systems are able to record (logging) laps data from the sensors, allowing replay of an entire running session or/and direct download to a personal computer equipped with a data analysis software. More sophisticated systems allow for more information such as lateral and longitudinal acceleration (or G-force), throttle position, steering wheel position and brake pressure.

Racing
Kart racing is generally accepted as the most economic form of motorsport available on four wheels. 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), KART (Karters of America Racing Triad).

In the UK, the MSA (Motor Sports Association) regulates most 'owner driver' Karting. Some associations, such as NatSKA (National Schools Karting Association), organize race meetings throughout the country under the authority of the MSA. Various four-stroke 'hire kart' series such as EPEC (European Prokart Endurance Championship) or BRKC (British Rental Kart Championship) fall outside the governance of the MSA. Billed as the UK's first national karting league, the Elite Karting League also falls outside of MSA governance.

In Australia, kart racing is administered by the Australian Karting Association on the behalf of FIA and CAMS. There is a manual released every year detailing the various rules and regulations that race meetings and drivers have to follow.

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

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 range from 1/4 mile (400 metres) to over 1 mile (1,600 metres) 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
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. This race has taken place since 1986 and its winners list include four times Champ Car champion Sébastien Bourdais (in 1996).

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 straights 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 is decided here. The current 2010 World Champion is Nyck de Vries from the Netherlands.

CIK-FIA categories:
 * KF1 (the top level), KF2, KF3, 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, both 125 cc gearbox categories.
 * Superkart, a 250 cc gearbox category.

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


 * MSA series: KF2, KF3, Formula KGP, Super Cadet and Cadet
 * Rotax series: Minimax, Junior Max, Senior Max, Senior Max 177
 * TKM series: Formula Junior TKM, Formula TKM Extreme, TKM Senior 4-stroke and since 2006, Honda Cadet

Other UK National Championships include: Birel Easykart (MSA Approved) series: Cadet 60cc, Junior 100cc, Senior Light 125cc, Senior Heavy 125cc

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

The BRKC is the UK's rental karting National championship, and the UK's official feeder series to the rental Kart World Championship.

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 Cadet (previously called Midget), Rookie, Junior National Pro, Junior National, Junior Clubman, Junior Rotax (Jmax), KF3, Senior National, Senior Rotax, Senior Clubman, Senior TAG (Restricted and Unrestricted). Most classes run a light and heavy category (with some running super heavy).

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

Driver equipment
For their safety, kart drivers are required to wear proper equipment:
 * Full-face helmet (Snell SA2005 or K2005 certification is required for racing, K2005 is same as SA2005 without fire resistance)
 * Driving suit (abrasion resistant overalls with at least one Cordura external layer, CIK-FIA Level 2 homologation for top level racing)
 * Gloves
 * Driving boots (ankles must be covered)

Rib protector and neck collar, although highly recommended, are optional in most countries. None of the above need to be made of fire retardant material. Superkart drivers are required to wear leather overalls, similar to those used in motorcycling.

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 and many former Formula One drivers grew up racing karts, most prominent among them, World Champions Ayrton Senna, Michael Schumacher, Alain Prost, Fernando Alonso, Kimi Räikkönen, Jenson Button, Lewis Hamilton and Sebastian Vettel. Many NASCAR drivers also got their start in racing from karts, such as Darrell Waltrip, Danica Patrick, Lake Speed, Ricky Rudd, Juan Pablo Montoya, Kiel Spaulding, Tony Stewart, and Jeff Gordon.

In August 2009, in anticipation to a possible return to F1 with Ferrari, Formula One world champion Michael Schumacher did some preparation driving a kart in Lonato, Italy. Schumacher also raced at the SKUSA SuperNationals, an event taking place each year in Las Vegas, along with F1 drivers Sébastien Buemi and Nelson Piquet, Jr.. Felipe Massa also used karting in September 2009 to test his condition in Brazil, two months after his Hungarian Grand Prix freak accident during qualifying.