In France, beware the Mistral

7/19/2022

From F1 to factory cars: here’s how the brakes of the future will be

For the fourth time running, the French GP will be held at the Circuit Paul Ricard of Le Castellet. According to Brembo technicians, the trans-Alpine track is classified as a circuit that is not very demanding on the brakes. On a scale of 1 to 5, it has a difficulty rating of 2, the joint lowest of the season with Silverstone.

It is a very technical track, with medium downforce and high-speed corners like Signes (turn 10), which the drivers take at full pelt and other very slow corners like Camp (turn 5) and Pont (turn 15). Starting at the front is vital to success: in the last 3 races, the poleman has always won.

Brembo carbon doesn't melt at 3,000°C (5,430°F) 

Carbon discs were first used in Formula 1 in the 1980s, before spreading to other motorsport competitions. No other element offers the same special combination of light weight, high thermal conductivity and absence of dilation, even at 1,000°C (1,832°F), which is the temperature that the Brembo F1 discs reach.

The density of carbon is 1.7 grams (0.06 oz) per cubic centimeter, compared with 7.8 grams (0.28 oz) for steel and 7.3 grams (0.25 oz) for gray cast iron. Its coefficient of thermal expansion is one-fifteenth of steel and one-eleventh of cast iron. The melting point of carbon is higher than 3,000°C (5,430°F), compared with the 1,200°C (2,190°F) of cast iron and 1,800°C (3,270°F) of steel.

On the road, 3 meters (3.3 yards) make all the difference 

Carbon discs aren’t suitable for road use, mainly because the braking system doesn't reach the minimum operating temperatures that this material needs, but also due to high consumption which is not compatible with day-to-day use. Some of their benefits, however, can be found in the carbon-ceramic discs of which Brembo, with Brembo SGL Carbon Ceramic Brakes - a joint venture with SGL Group - is the main worldwide manufacturer.

On average, carbon-ceramic discs allow a saving of 5-6 kg (11-13 lbs) in weight compared to traditional cast iron discs. What's more, their lifespan may even match that of the vehicle they're mounted on. It depends on how it's driven. But, above all, carbon-ceramic guarantees a reduction of about 3 meters (3.3 yards) in the braking distance from 100 km/h to 0 km/h (62 mph - 0 mph) compared with a traditional disc.

Discover all the benefits of carbon-ceramic discs.

1, 10, 100 

On the Circuit Paul Ricard, the F1 cars use their brakes 10 times on each lap, but only with a maximum of three turns in a row, corners 3-4-5. The drivers use their brakes for over 16 seconds on each lap which amounts to 17 per cent of the duration of the race. The amount of time the brake system is used is less than one second on only one of the 10 braking episodes.

On 5 braking episodes, the speed drops by over 100 km/h (62 mph) but only more than 140 km/h (87 mph) in one case. Three of the braking episodes have a deceleration of at least 4G all in the first half of the circuit. From corner 9 onwards, the load on the brake pedal never reaches 100 kg (220 lb). From the starting line to the checkered flag, each driver exerts a total load of over 50.5 metric tons on the brake pedal.

Beware the Mistral 

Of the 10 braking sections at the French GP, 2 are classified as very demanding on the brakes, 1 is of medium difficulty, and the remaining 7 are light.

The most demanding braking is on turn 8, the chicane that bisects the 1.8 km (1.1 mile) Mistral straight. The cars come onto it at 319 km/h (198 mph) and brake for 2.12 seconds covering a distance of 116 meters (381 feet) before going into the turn at 135 km/h (84 mph). The drivers have to exert a load of 141 kg (310.8 lb) and are subjected to a deceleration of 4.7G. The figures for corner 1 are slightly lower: deceleration is 4.6 G and the braking force 2,495 kW. Corner 14, on the other hand, has the longest braking distance, 120 meters (393 feet) and the second longest braking time, 2.19 seconds.

And what about the video games?

Perfect braking on the Mistral chicane is not easy in the Formula 1 video game, especially when doing it for the first time, because the different track layouts can be misleading. It is a good idea to move onto the right-hand side of the tarmac and slam on the brakes after passing the advertisement overpass. After downshifting to 4th gear, move the left-hand wheels onto the inner curb and then reopen the throttle.

In France, beware the Mistral

From F1 to factory cars: here’s how the brakes of the future will be

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