Semi-automatic
A semi-automatic transmission is a type of gearbox used in racing cars that automatically handles the clutch but still requires the driver to manually change gears, usually by pulling paddles behind the steering wheel.
In a regular road car with a manual transmission, the driver has to press a clutch pedal with their left foot every time they want to change gears. With a semi-automatic transmission, the car takes care of the clutch operation automatically. The driver still decides when to shift up or down through the gears, but they don't need to worry about operating a clutch pedal. This is why semi-automatic transmissions are sometimes called "clutchless manual" or "auto-clutch manual" transmissions.
Most racing cars with semi-automatic transmissions use paddle shifters mounted behind the steering wheel. The driver pulls the right paddle to shift up a gear and the left paddle to shift down. This setup allows drivers to keep both hands on the wheel while changing gears, which is crucial during high-speed racing.
Semi-automatic transmissions offer several advantages in motorsport. They allow for much faster gear changes than traditional manual transmissions because the automated clutch system can operate more quickly than a human foot. Some racing semi-automatics can complete a gear change in less than 60 milliseconds, which is faster than a blink of an eye. This speed helps maintain the car's momentum and power delivery during shifts.
These transmissions also reduce the driver's workload during a race. Operating a clutch pedal hundreds of times during a race while also steering, braking, and managing other controls can be physically exhausting. By eliminating the clutch pedal, semi-automatic transmissions let drivers focus more on racing lines, braking points, and overtaking maneuvers.
Ferrari introduced the first semi-automatic transmission in Formula One with their 640 car in 1989. This revolutionary system used hydraulic actuators and electrical controls to manage the clutch and gear changes. The technology quickly spread throughout Formula One and other top racing series because of its performance benefits.
Today, semi-automatic transmissions are standard equipment in Formula One, IndyCar, and many touring car racing series. Road car manufacturers have also adopted similar technology, with brands like Ferrari and BMW offering semi-automatic transmissions in their high-performance street cars. British television presenter Jeremy Clarkson famously nicknamed these systems "flappy-paddle gearboxes" because of the paddle-shifting mechanism.
It's worth noting that not all racing series allow semi-automatic transmissions. Some championships require traditional H-pattern manual gearboxes to maintain a certain level of driver skill requirement or to control costs. However, where regulations permit their use, semi-automatic transmissions have become the preferred choice due to their speed and efficiency advantages.