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THE MACHINES - THE KARTS A modern racing kart is a sophisticated, high-tech racing vehicle with performance numbers more impressive than you'd imagine. A horsepower to weight ratio comparable to a racing motorcycle, today's kart can reach 60mph in under 4 seconds. Cornering in a kart is an unbelievable experience as some karts can apply over 3g's to a driver's body. Karts also have Formula One style data acquisition through on-board computers, with download capabilities to a laptop in order to analyze each session on the track. The skill and technical knowledge required to win at the highest level of karting can compare to that of a high budget race car team in IRL, ChampCar, ALMS, even Formula One and other formulas. The kart chassis is made of steel tube or alloy with a fiberglass seat and full plastic bodywork. There is no suspension therefore the chassis has to be flexible enough to work as a suspension and stern enough not to break or give way in a turn. Karts come equipped with disc brakes and use pneumatic slick racing tires on either aluminum or magnesium wheels. Most kart manufacturers used CAD technology to design and build frames and components. Some even use robots for welding. Frames are usually powder coated and some components are CNC machined and anodized. 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 to be added or removed according to race conditions. Racing karts use small 2-stroke or 4-stroke engines. 2-stroke engines were originally taken from motorcycles, but have become a kart specialized item with dedicated manufacturers. IAME (Parilla, Komet), TM, Vortex, Yamaha and Rotax are manufacturers of such engines. These can develop from about 16 hp to 32 hp for a single-cylinder 100cc unit to 90 hp for a twin 250cc. The most popular categories worldwide are those using 100cc engines and the "Touch-and-Go" 125cc units. 100cc 2-stroke kart engines can run at 19,000 rpm. 4-stroke engines are typically standard air-cooled lawn mower engines, sometimes with small modifications, developing from about 5 to 20 hp. Briggs & Stratton, Tecumseh, Kohler, Robin, and Honda are manufacturers of such engines. Karts vary in speed and some (Superkart) can reach speeds exceeding 160 mph. A Formula A kart, with a 100cc 2 stroke engine and an overall weight including the driver of 330lbs, can accelerate from 0-60 mph in under 4.5 seconds, and has a top speed of 85 mph. It takes a little more than 3 seconds to go from 0 to 60 mph with a 125cc shifter kart (6 gears), with a top speed of 125 mph on long circuits. . |
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