Tuesday, September 16, 2008

Cars and technology

Modern Formula One cars are mid-engined open cockpit, open wheel single-seaters. The chassis is made largely of carbon fibre composites, rendering it light but extremely stiff and strong. The whole car, including engine, fluids and driver, weighs only 600kg - the minimum weight set by the regulations. The construction of the cars is typically lighter than the minimum and so they are ballasted up to the minimum weight. The race teams take advantage of this by placing this ballast at the extreme bottom of the chassis, thereby locating the centre of gravity as low as possible in order to improve handling and weight transfer.
The cornering speed of Formula One cars is largely determined by the aerodynamic downforce that they generate, which pushes the car down onto the track. This is provided by 'wings' mounted at the front and rear of the vehicle, and by ground effect created by low pressure air under the flat bottom of the car. The aerodynamic design of the cars is very heavily constrained to limit performance and the current generation of cars sport a large number of small winglets, 'barge boards' and turning vanes designed to closely control the flow of the air over, under and around the car.
The other major factor controlling the cornering speed of the cars is the design of the tyres. Since 1998, tyres in Formula One have not been 'slicks' (tyres with no tread pattern) as in most other circuit racing series. Instead, each tyre has four large circumferential grooves on its surface designed to limit the cornering speed of the cars Slick tyres will return to Formula One in the 2009 season. Suspension is double wishbone or multilink all round with pushrod operated springs and dampers on the chassis. Carbon-Carbon disc brakes are used for reduced weight and increased frictional performance. These provide a very high level of braking performance and are usually the element which provokes the greatest reaction from drivers new to the formula.
Engines must be 2.4 litre naturally aspirated V8s, with many other constraints on their design and the materials that may be used. Engines run on unleaded fuel closely resembling publicly available petrol. The oil which lubricates and protects the engine from overheating is very similar in viscosity to water. The 2006 generation of engines spun up to 20,000 rpm and produced up to 780 bhp (582 kW).For 2007 engines are restricted to 19,000 rpm with limited development areas allowed, following the engine specification freeze from the end of 2006.
A wide variety of technologies – including active suspension, ground effect and turbochargers – are banned under the current regulations. Despite this the current generation of cars can reach speeds of up to 350 km/h (around 220 mph) at some circuits. A Honda Formula One car, running with minimum downforce on a runway in the Mojave desert achieved a top speed of 415 km/h (258 mph) in 2006. According to Honda the car fully met the FIA Formula One regulations. Even with the limitations on aerodynamics, at 160 km/h aerodynamically generated downforce is equal to the weight of the car and the often repeated claim that Formula One cars create enough downforce to 'drive on the ceiling' remains true in principle, although it has never been put to the test. At full speed, downforce of two and a half times the car's weight can be achieved. The downforce means that the cars can achieve a lateral force of up to five times the force of gravity (5g) in cornering – a high-performance road car like the Ferrari Enzo only achieves around 1g.Consequently in corners the driver's head is pulled sideways with a force equivalent to 20kg. Such high lateral forces are enough to make breathing difficult and the drivers need supreme concentration and fitness to maintain their focus for the one to two hours that it takes to complete the race.

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