ENGINES / GEAR BOX

The engine and transmission of a modern Formula One car are some of the most highly stressed pieces of machinery on the planet, and the competition to have the most power on the grid is still intense.

Traditionally, the development of racing engines has always held to the dictum of the great automotive engineer Ferdinand Porsche that the perfect race car crosses the finish line in first place and then falls to pieces. Although this is no longer strictly true - regulations now require engines to last more than one race weekend - designing modern Formula One engines remains a balancing act between the power that can be extracted and the need for just enough durability.

Engine power outputs in Formula One racing are also a fascinating insight into how far the sport has moved on. In the 1950s Formula One cars were managing specific power outputs of around 100 bhp / litre (about what a modern 'performance' road car can manage now). That figure rose steadily until the arrival of the 'turbo age' of 1.5 litre turbo engines, some of which were producing anything up to 750 bhp / litre. Then, once the sport returned to normal aspiration in 1989 that figure fell back, before steadily rising again. The 'power battle' of the last few years saw outputs creep back towards the 1000 bhp barrier, some teams producing more than 300 bhp / litre in 2005, the final year of 3 litre V10 engines. Since 2006, the regulations have required the use of 2.4 litre V8 engines, with power outputs falling around 20 percent.

Revving to a limited 18,000 RPM, a modern Formula One engine will consume a phenomenal 650 litres of air every second, with race fuel consumption typically around the 75 l/100 km (4 mpg) mark. Revving at such massive speeds equates to an accelerative force on the pistons of nearly 9000 times gravity. Unsurprisingly, engine-related failures remain one of the most common causes of retirements in races.

Modern Formula One engines owe little except their fundamental design of cylinders, pistons and valves to road-car engines. The engine is a stressed component within the car, bolting to the carbon fibre 'tub' and having the transmission and rear suspension bolted to it in turn. Therefore it has to be enormously strong. A conflicting demand is that it should be light, compact and with its mass in as low a position as possible, to help reduce the car's centre of gravity and to enable the height of rear bodywork to be minimised.

The gearboxes of modern Formula One cars are now highly automated with drivers selecting gears via paddles fitted behind the steering wheel. The 'sequential' gearboxes used are very similar in principle to those of motorbikes, allowing gear changes to be made far faster than with the traditional ‘H’ gate selector, with the gearbox selectors operated electrically. Despite such high levels of technology, fully automatic transmission systems, and gearbox-related wizardry such as launch control, are illegal - a measure designed to keep costs down and place more emphasis on driver skill. Transmissions - most teams run seven-speed units - bolt directly to the back of the engine.

Mindful of the massive cost of these ultra high-tech powertrains, the FIA introduced new regulations in 2005 limiting each car to one engine per two Grand Prix weekends, with 10-place grid penalties for those breaking the rule. From 2008, a similar policy was applied to gearboxes, each having to last four race weekends. 2009 saw the introduction of even more stringent engine rules, with drivers limited to eight engines per season. On top of these measures, a freeze on engine development imposed at the end of the 2006 season means teams are unable to alter the fundamentals of their engines’ design until at least 2010.