Transmission gearing in motorsports applications

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Transmission gearing provides an optimum torque-speed conversion, more commonly referred to as ‘gear reduction’ from a higher speed motor to a much more forceful output, by using the principle of mechanical advantage.
In the arena of motorsports, where high speeds are the norm, transmission gearing is an important area of engineering, as the drivers run at very high speeds and require precision control during sharp corner maneuvering.

Transmission failure in motorsports amounts to the vehicle being ousted by competitors, or making an untimely exit in the race. Automotive engineers and manufacturers test their prototypes to avoid this at all costs.
Transmission gear failure is the result of significant amount of added stress with the increase of horsepower, which is substantially large in a F1 car, or a high speed rally car. Motorsports requires heavy duty transmission gears.

Predetermined number of drive ratios in motorsports (R1-R4, 1G-10G) in combination with gear transmission, are taken to modify the automatic shift of the gear to accommodate the different loading scenarios of the transmission.

Automatic shifting of a gear transmission with speed and load controls in the context of high and low drive ratios is attained by the different step by step changes in shift patterns. Modern gearboxes reduce inappropriate high speeds and low torque of the main output shaft, to a much more stable lower speed with a greater torque.
The opposite is also attained, producing a mechanical advantage, allowing higher torque generation.

Although the internal set up of a formula one car includes a clutch, gearbox and differential resembles that of any other production car, but the transmission system in a F1 car is configured to transfer the 900 bhp on to the rear wheels, which is radically different from an ordinary car.
The clutch of a formula one car is linked directly to the engine and is fixed between the gearbox and the engine. This clutch is electro hydraulically run, and include multi plate designs to enhance engine pick up. The clutch in a racing car weighs very little, which means that they have low inertia, thus enabling faster changes of gear. Race car drivers do not manually operate the clutch with the exception of moving away from the standstill. When it comes to changing gears, a lever behind the wheel is pressed, to arrive at the next gear ratio.

This entire process is controlled by an on board computer, which automatically adjusts the clutch and switches the ratios within fractions of a second. Left side clutches are in general designed for rally based cars, while ride side clutches are used in F1 cars.

Racing car gearboxes have no synchromesh, and are semi automatic.
The sequential manner of running resembles that of a motorcycle gearbox, with gears being changed via a rotating barrel containing selector forks. Without synchromesh, the engine electronics have to synchronize the engine’s speed with the internal gearbox speed before shifting a gear. Motorsports teams build their individual gearboxes, with regulations stating that cars should have the minimum of 4 and max of 7 forward gears, along with a reverse gear.

Most race cars have 6 forward gears, although increasingly a seventh one is being included. The suspension of race cars’ rear wheels affects the gear casing directly, holding the entire weight of the rear end of the car.
This means that the gearboxes have to be made out of a very strong material, so in the earlier years it was made out of stressed magnesium. However, with the advancement of materials manufacturing, many teams have developed titanium, and lately the carbon-fiber gearbox casings, making them strong yet light.
This has helped with greater weight distribution.
Racing cars use limited-slip differentials to maximize the corner tractions, as opposed to the open differentials of ordinary cars. A limited slip differential uses friction to alter the torque relationship between the drive wheels.