Formula 1 cars are started much differently than a road car. These cars do not have keys or even an on board starter. In order to start the engine, an external unit called a starter motor is used. The starter motor has a long wand that is inserted into the back of the gearbox by a mechanic. Once the wand is plugged in, the mechanic presses a button which pushes 24 volts into the gearbox and turns the engine. The starter is attached to a trolley and can be rolled up to the back of the car.
Andy Barber, a McLaren Racing Sub- Assembly Technician, explains, “…the mechanic inserts the wand in the gearbox, he then receives a signal to push the starter motor button. This turns the engine over until the engineers are happy with the engine speed and oil pressure and – using a laptop – they will effectively turn the ignition on”
The starter motor has a set of gears and a clutch. It also contains a sprag clutch that operates like a freewheel on a common bicycle. This allows the mechanic to safely pull out the wand once the engine starts up. A break-off clutch also is another integrated safety device which prevents an unnecessary accident if the engine backfires.
Source: f1technical.net
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