Formula One glossary

Hairpin

A very tight and slow corner, that usually is a bend of more than 100°. The most known examples are 'Grand Hotel' in Monaco en 'La source' in Spa Francorchamps. On modern circuits, hairpins are often located at the end of a long straight in order to ease overtaking.

Handling

The relative ability of a vehicle to negotiate curves and respond to road conditions. It is a factor of the weight of the vehicle, the suspension, tires, air flow, etc.

Harmonic balancer

Also called vibration damper. It usually is a solid crankshaft fan belt pulley that has a weight ring bonded by rubber to the inner crankshaft-mounted ring. The outer ring absorbs and cancels out crankshaft vibrations that otherwise might cause the crankshaft to break.

Heat cycle

A tire that has been heated up through use and then cooled down has experienced one heat cycle. This often results in a slight hardening of the tire compound, which can make the tire perform at a high level for a longer period of time. (cfr Scrubbed tyres)

Helical

A spiralling shape such as that made by a coil spring. In the shape of a helix.

Helical differential

Virtually all gears in modern cars are cut with a spiral helix angle rather than straight meshing. Straight gears are simpler to manufacture, but are extremely noisy.

Helical gear

A gear that has the teeth cut at an angle to the center line of the gear. This kind of gear is useful because there is no chance of intermittent tooth-to-tooth operation because there are at least two teeth engaged at any time. Also helical gears tend to operate quieter than straight-cut gears.

Honeycomb

An inner filling made of aluminium in a honeycomb pattern which gives strength and rigidity to carbon fibre and Kevlar with little weight penalty.

Horizontally opposed engine

Also called a boxer engine, the design consists of two banks of cylinders that are placed flat or 180 degrees apart. The configuration allows to build an engine with the lowest possible centre of gravity and can be beneficial for aerodynamic cover around it.
Flat engines have been used in F1 by Ferrari in the early 1980s. The type was later abandoned as it was not optimal as a stressed member of the chassis, while eventually in 2006 it was banned altogether as only 90° banks are allowed.

Horsepower

An old non-metric unit to measure power. There are various definitions of horsepower, but the original value is mechanical horsepower. In that definition, one hp is equal to the ability to lift 33,000 pounds one foot in one minute. In metric terms, it is the ability to raise 250 kg a distance of 30 cm in one second. It is also equal to 745.7 W.

Hydraulic

When a quantity of water, oil, or other fluid is forced along one end of a line, it also forces against the other end of the line. Because these fluids (unlike a gas) cannot be compressed, when they are forced into a smaller cylinder they multiply the amount of force. Thus a driver can apply a small amount of force on the pedal or lever and a great amount of force is applied to the brake. Used in power steering, clutches, and brake systems.