ROME, Mich.–Times change, contexts change, but Brembo continues to take on new technological challenges. In the early 1970s, Alberto Bombassei (son of Emilio, founder of Brembo) was not much more than 30 years old when he approached Piero Ferrari, asking to meet his father. This was how it came to be that Enzo Ferrari entrusted him with supplying brake discs, in cast iron at the time, for the Scuderia Ferrari.
Brembo has always been committed to researching innovative solutions for motorsports, and the latest challenge the Company is facing involves the Formula E championship. This competition serves as a very valuable mobile laboratory for the development of technology applied to electronics, which is the primary challenge for the future – if not the present – of the automotive industry.
As everyone knows, the braking performance of each vehicle is affected by the mass of the vehicle itself, the tires used, and the way the brakes are used during a track session (practice or the race), obviously in addition to the characteristics of the braking system. For these reasons, Formula 1 and Formula E are much more different than they might seem at first glance.
Braking is also influenced by the tire contact patch, which affects the ability to discharge braking torque to the ground. Despite having 18-inch rims instead of the 13-inch Formula 1 rims, Formula E cars have narrower tires; they are 260 mm wide in the front and 305 mm in the rear, compared to 370-385 mm in the front and 455-470 mm in the rear of the Formula 1 cars.
The difference in the duration of the races is also important. The Formula E cars race 45 minutes plus one lap while the Formula 1 single-seaters drive at least 300 km (186 miles). This translates into the Formula 1 cars being obligated to race anywhere from a minimum of 1 hour 16 minutes (race record set by Lewis Hamilton in Monza in 2018) up to a maximum of 2 hours, the establish time according to regulations.
Since the energy to be absorbed in braking is actually kinetic energy, vehicle speed at specific points on the track is a fundamental element in determining the size of the brakes. From this standpoint, Formula 1 dominates Formula E because its maximum speed is more than 360 km/h (224 mph), while the electric single-seaters only get up to 280 km/h (174 mph).
Since its cars are so different from Formula 1 vehicles, Formula E asked for a custom braking system. Formula E cars have less braking force and spend less time braking in general since the races do not last as long, so there is less wear of the friction material (discs and pads).
This explains the reduced thickness of the Formula E carbon discs and pads. In the front the discs are 24 mm thick and the pads are 18 mm thick, while in the rear the discs are 20 mm thick and the pads are 16 mm thick. The Formula 1 measurements are decidedly higher: In the front the discs are 32 mm thick and the pads are 22 mm thick, while in the rear the discs range from 28 to 32 mm thick and the pads are 17 mm thick.
The thicker Formula 1 discs provide more space for the ventilation holes, which count about 1,400 holes on each 2.5 mm disc. Plus, the advanced research Brembo conducts on the aerodynamics of these cars enables the Company to customize the cooling design and satisfy the requests of each customer.
On the Formula E cars, on the other hand, there are about 70 ventilation holes on the front discs and 90 on the rear. The front discs are 6.2 mm in diameter and the rear discs are 4.2 mm. These same measurements were found on the Formula 1 discs up until 2007, which leads us to believe that within a decade, the number of holes on the Formula E discs will most likely be multiplied to coincide with a reduction in their size.
To return the discs to the right operating temperature in a matter of seconds, each Formula 1 team uses Brembo brake discs that have a variable number of holes and a geometry that correspond to the specific circuit configuration and ambient temperature. In Formula E, on the other hand, in keeping with the principles of containing costs and maximizing performance uniformity, the brake discs are the same for the entire championship and for all the single-seaters.
This concept is applied to all the braking system components including the discs, pads, calipers (only one type for the front and one for the rear), bushing mounted housing, and the tandem master cylinder. In addition, this tandem master cylinder feeds both the front and the rear systems, forcing fixed braking distribution.
Don’t be misled by the word ‘carbon’: The carbon used in Formula E was selected based on the needs of an entirely electric vehicle and is much different than the carbon used in Formula 1. Although both are monobloc billet, the brake calipers are different too: The 6-piston caliper used in Formula 1 is made of nickel-plated aluminum and the 4-piston caliper used in Formula E is made of oxidized aluminum alloy.
On the other hand, the material of the brake pads (carbon) and the diameter of the front discs (278 mm) in both championships is the same. Also, the maintenance schedules are similar for the calipers, which are periodically sent back to Brembo Racing where every component is disassembled, cleaned and checked. They are inspected about every 2,500 km (1,552 miles), the perfect amount of time to ensure they are operating correctly.
