Braking is the process which brings about deceleration in the car. The technology incorporated in Formula 1 cars is very close to the technology that powers the brakes in modern road cars that we drive; except for the materials involved. All the cars on the grid now use carbon fibre composite brake discs which save weight and are able to operate at higher temperatures than steel discs. A typical Formula One brake disc weighs about 1.5 kg (versus 3.0 kg for the similar sized steel discs used in the American CART series). These are gripped by special compound brake pads and are capable of running at vast temperatures - anything up to 750 degrees Celsius. Previously different sized discs would be used for qualifying and racing, but the 2003 changes to the rules means that all cars enter parc ferme after qualifying - and so therefore set their one-lap time on their race brakes.
Formula 1 car has incredibly powerful brakes and can slow down from 125mph to a standstill in just 55 meters. This process takes 1.9 seconds and generates deceleration forces of up to 5g, making the driver feel five times his normal weight which is enough to force teardrops from driver's eyes. During normal street driving, cars tend to brake early to be safe but this is exactly opposite of what is followed in racing. Braking is very late so as to gain maximum advantage in terms of time. Hence the braking system needs to be very effective and precise. In physical terms we can state that energy is the power to do work. When a Formula 1 car comes down a straight line at 300 km/h or more, that car has lots of kinetic (movement) energy. Due to the fact that energy does not get lost, but can only be transformed one kind into another, at braking most of the kinetic energy is transformed into potential energy, more specifically heat and light. During braking, the carbon brake disks, which are used in Formula 1, heats up to 1000 degrees centigrade in one second and glow red hot. Formula 1 cars have carbon disc brakes with rotating discs (attached to the wheels) being squeezed between two brake pads by the action of a hydraulic calliper. Too much braking through a wheel will cause it to lock as the brakes overpower the available levels of grip from the tyre. Formula 1 previously allowed anti-skid braking systems, which works by applying and releasing pressure on brake discs very rapidly to stop wheels locking up and to allow the driver to maintain steering control, but these were banned in the 1990s. Braking therefore remains one of the sternest tests of a Formula 1 driver's skill.
FIA regulations for Formula 1 brakes
Formula One cars must have one brake system operated through a single brake pedal. However, the system must comprise two hydraulic circuits - one for the front wheels and one for the rear. Should one circuit fail the other must remain operational. Power brakes and anti-lock braking systems (ABS) are not allowed.
Each wheel must have no more than one brake disc of 278mm maximum diameter and 28mm maximum thickness. Each disc must have only one aluminium caliper, with a maximum of six circular pistons, and no more than two brake pads.
The size of the air ducts used to cool the brakes is strictly controlled and they must not protrude beyond the wheels. The use of liquid to cool the brakes is forbidden
