Often overlooked in today’s Formula 1 narrative, braking remains one of the areas of performance where the driver and car can make the most difference. The state of the art achieved by the current systems in use in motorsport, however, is such that in almost all cases the limit in braking is no longer represented by the performance of the braking system itself, as much as by the grip available to the tires and therefore indirectly by the aerodynamic load given off by each single-seater. Furthermore, the reliability achieved by the braking components, thanks to the constant research conducted by companies in the sector, among which the Brembo name stands out, makes it increasingly rare to witness withdrawals caused by malfunctioning or failure of the system. The attention for the public towards the brakes has thus progressively waned, although the technology involved and the importance in the overall balance remain first level.
However, the first races of 2022 could reinvigorate interest in the braking system. In fact, Brembo, after a career that has 463 Grand Prix Formula 1 races, 47 competed seasons, 27 drivers ‘titles and 31 manufacturers’ championships, has found itself facing a new challenge in the design, manufacture and supply of its components. All this stems from the passage of single-seaters to 18-inch diameter rims, against the 13-inch of the previous generation of cars. A larger volume was thus created inside the wheel unit, which allowed the caliper-disc assembly to be enlarged. The diameter of the front discs increased from 278 to 328 mm, with an unchanged thickness of 32 mm. At the rear, on the other hand, the diameter has risen to 280 mm from the previous 266 mm, with the thickness also being increased from 28 to 32 mm. Larger dimensions result in a higher mass, with an increase of about 700 grams per wheel, for a total of about 3 kg. All this has repercussions in a greater thermal capacity, therefore better ability to absorb heat without causing an excessive increase in temperatures. Yet, controlling temperatures and overheating is one of the main headaches at the start of the season.
Firstly, the minimum weight of the cars went from 752 kg in 2021 to 795 kg, then further raised to 798 kg after the recent directive that allows the use of tie rods to stiffen the bottom and counteract the porpoising phenomenon. There is therefore more kinetic energy to be dissipated in detached, which has repercussions in a greater braking work, therefore more heat dissipated and consequently an increase in temperatures. Then there are the new problems concerning the cooling of the system. The technical regulation 2022 in fact requires the sealing of the baskets to reduce the heat exchange between the disc and the tire. The baskets themselves, together with the cooling ducts, are classified as prescribed components and therefore their design must respect the FIA specifications. Finally, the external fairing of the rims was of great impact, which prevents the cooling air from being evacuated externally, with the obligation to vent from the inside of the wheel. There is therefore a greater difficulty in removing the heat dissipated by the brakes, which according to what Pirelli reported has caused an increase in tire temperatures of between 5 and 10 ° C, which is why it is reasonable to expect an even greater increase in the caliper-disc assembly.
The same aerodynamics inside the baskets are subject to restrictions. The minimum diameter of the ventilation holes of the discs used for their cooling is imposed at 3 mm, while up to 2021 there were holes with a diameter of up to 2.5 mm. This limit prevents optimizing the surface exposed to the air for disc cooling, as can be seen from the reduction in the number of holes: between 1000 and 1100 at the front against 1480 in 2021, while at the rear there are 900 units. 150 less than last season. Even the pads, of which two different compounds can be supplied, can no longer be punctured by regulation.
We therefore understand how much the variables involved in the equation have changed. On the one hand there is an increase in the heat to be dissipated and on the other there are strong constraints on the cooling of the system. The teams are still intent on taking measures on how to react to the news, with McLaren that during the tests it was the team that suffered the most from overheating problems. The Woking team therefore presented itself to the first race in Bahrain with updates in the cooling ducts, aware that the possible recurrence of the problem would seriously compromise the race and could even prove to be terminal.
The different sizes of the discs have forced to review the geometry of the calipers and pads as well. On this front, 2022 marks an important milestone for Brembo, as for the first time all the teams are equipped with calipers produced by the Italian group. In detail, nine teams mount Brembo components while one team uses AP Racing calipers, a Coventry-based company, which was recently acquired by the Bergamo group. But be careful to define it as a standard mono-supply, because while sharing Brembo’s support, the teams differ in the characteristics of their calipers, even though they are all six-piston aluminum alloy machined from billet and nickel-plated. In fact, the Italian company supports each team and manufactures the calipers on the basis of the specifications provided according to the optimal ratio between mass and stiffness required by the team. This is a further element of differentiation between the carsas on the one hand the difficulties of the teams in reaching the minimum weight would induce to lighten the components, but on the other hand the rigidity proved to be decisive for the 2022 single-seaters to be able to generate the maximum load from the bottom and from the Venturi channels in all driving conditions.
The great stiffness with which the suspension groups are calibrated according to aerodynamics makes it 2022 cars particularly prone to locking the front when braking. The large pressure oscillations in the contact footprint between the tires and the ground, not properly damped, reduce the available grip, thus frequently witnessing braking with smoking wheels, harmful both for the lap time and for the wear of the tires. The modulation of the braking therefore becomes a priority, in particular the breakdown of braking torque between front and rear e its migration, that is the variation of the distribution itself during the single braking. The management of the brake-by-wire then comes into play, the system that balances the braking contributions to the rear of the hydraulic system, of the regenerative braking and of the engine brake, whose settings influence precisely the distribution and the braking migration. In 2022, five teams will be fitted with brake-by-wire units developed by Brembo and AP Racing. In the first races, therefore, eyes focused on the effectiveness of control and exploitation of the braking systems, which have passed into the background in the eyes of the public in the recent past, but whose popularity could return to the fore with the new regulations.
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