Throw a Belt

To "throw a belt" in motorsport means when a drive belt that connects the engine to important parts of the car suddenly comes loose, breaks, or falls off completely during racing.

In racing cars, belts work like rubber bands that transfer power from the spinning engine to other crucial components. The most common example happens in drag racing, where the belt connecting the engine to the supercharger (a device that boosts engine power) gets thrown off due to extreme forces and high speeds.

When drivers throw a belt, it can also refer to the serpentine belt, which is the long belt that runs multiple engine accessories like the alternator and water pump. Sometimes, though rarely, it can even mean safety belts that secure the driver become loose or disconnected.

Several things cause belts to fail during racing. High engine speeds create intense vibrations that can shake belts loose. Misaligned pulleys (the round wheels the belt wraps around) can cause the belt to slip off. Dirt, debris, and extreme heat from racing conditions can also wear down belts faster than normal driving.

The consequences of throwing a belt depend on which belt fails. If a supercharger belt comes off, the car immediately loses significant power, making it nearly impossible to compete effectively. A thrown serpentine belt can cause the engine to overheat or lose electrical power. In extreme cases, a shredded belt can even damage internal engine parts.

For drivers, throwing a belt usually means their race is over. They either have to retire immediately or make an emergency pit stop for repairs, losing valuable time and position. In professional racing, teams often carry spare belts and practice quick belt changes, but the time lost can still ruin a race result.

Preventing belt failure involves regular inspection, proper alignment, using high-quality racing belts, and ensuring all pulleys and tensioners are in good condition before each race.