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 605 kg. In fact this is the minimum weight set by the regulations – the cars are so light that they often have to be ballasted up to this minimum weight.
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 the movement of air under the flat bottom of the car.
A significant difference in the design of the latest breeds of F1 cars is that they make far greater use of vortex “lift,” or in this case, downforce. Since a vortex is a rotating fluid that creates a low pressure zone at its center, creating vortices lowers the overall local pressure of the air.
Since low pressure is what is desired under the car, allowing normal atmospheric pressure to press the car down from the top, by creating vortices, downforce can be augmented while still staying within the rules.
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 “barge boards” in particular are designed, shaped, configured, adjusted and positioned not to create downforce directly, as with a conventional wing or underbody venturi. They are designed so that air spillage from their edges will create these vortices.
The other major factor controlling the cornering speed of the cars is the design of the tyres. Tyres in Formula One are not ‘slicks’ (tyres with no tread pattern) as in most other circuit racing series. Each tyre has four large circumferential grooves on its surface designed to further limit the cornering speed of the cars. 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 are mandated as 2.4 litre normally aspirated V8s, with many other constraints on their design and the materials that may be used. The 2006 generation of engines rev close to 20,000 rpm and produce up to 740 bhp (552 kW). The previous generation of 3-litre V10 engines are also allowed, albeit with their revs limited and with an air restrictor to limit performance.
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. For 2007 the V8 engines will be restricted to 19,000 rpm with limited development areas allowed, following the engine specification freeze from the end of 2006. As outright speed and power are effectively being capped it is widely believed that teams will work on improving reliability, and the torque range of the engine to improve driveability.
A wide variety of technologies – including active suspension, ground effect aerodynamics and turbochargers – are banned under the current regulations. Despite this the 2006 generation of cars can reach speeds of up to 350 km/h (around 220 mph) at some circuits (Monza).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 are capable of ‘driving on the ceiling’ remains true in principle, although it has never been put to the test. At full speed downforce of 2.5 times the car’s weight can be achieved.
The downforce means that the cars can achieve a lateral force of around four and a half times the force of gravity (4.5 g) in cornering – a high-performance road car might achieve around 1 g. Consequently in corners the driver’s head is pulled sideways with a force equivalent to 25 kilograms. Such high lateral forces are enough to make breathing difficult and the drivers need supreme concentration to maintain their focus for the 1 to 2 hours that it takes to cover 305 kilometres.