Putting On The Brakes

Brembo entered into racing in 1975, when Maranello’s patron, Enzo Ferrari, entrusted the Bergamo company with the task of attending to the most prestigious Formula 1 car. As a result of Brembo’s association with Ferrari, the company soon became the leader in braking systems for racing vehicles. Since that time, teams equipped with Brembo brakes have won hundreds of car and motorcycle world championships.

The U.S. version of the Mitsubishi Lancer EVO (below) wears the same ventilated disc/aluminum caliper combination as the Subaru Impreza WRX (bottom).

Subsequently, Brembo brakes have crossed over to street legal vehicles. In the 2003 model year Brembo provided original equipment braking systems for the Nissan 350Z, BMW X5, Infiniti G35, Mustang Cobra R, Volvo S60 R and Dodge Viper, Mitsubishi Lancer Evolution and the Subaru Impreza STI as well as every Porsche model. This list is a who’s who of street legal rockets. Clearly, a large number of high performance automakers seek the stopping power that aided so many championship racing teams.

As a vehicle designed for rally competition, every Mitsubishi Lancer Evolution is equipped with Brembo aluminum opposed calipers and rotors at the front and rear of the vehicle. The front ventilated discs measure 320 mm (12.65 inches) in diameter and the rear ventilated discs measure 300 mm (11.8 inches) in diameter. The front aluminum opposed caliper relies on a four-piston design while the rear brakes employ a large diameter two-piston design. The Lancer Evolution sedan is equipped with tandem vacuum boosters and master cylinders that create a reduced pedal ratio that improves pedal stiffness and modulation to achieve better braking balance with improved pedal effort and feel.

“Brembo brake systems were selected because of their superior performance and because they met our development target,” says Mitsubishi. “The development was collaboration with Brembo for our Evolution exclusively. We have been installing the Brembo brakes system since the Evolution 5 which was launched in January 1998 for domestic market. Brembo brakes are excellent in its performance as well as its practicability and meet the Evolution character as the high performance sporty car.”

The Subaru STI, arch nemesis of the EVO, has also been outfitted with Brembo’s braking systems. The two cars are competing for the same upscale tuner market dollar and the braking systems are nearly identical. The STI also features ventilated four-wheel disc brakes with four-piston calipers up front and two-piston calipers in back. The STI then combines the Brembos with an electronic brake force distribution system.

Subaru’s selection of the Brembo for the braking system was also based on faith in the quality of the products as well as product confidence due to pervious dealings.

But Brembo has a long history of customer loyalty. Brembo S.p.A. was founded in 1961 in a small mechanic’s garage located in Bergamo, Italy, and was run by current President Emilio Bombassei’s father. The senior Bombassei gave the company a strong family element right from the start. Experience in mechanics and metallurgy was put to use when the founder started working for customers like Alfa Romeo.

The year 1964 marked a milestone in the company’s history: At that time, Brembo began manufacturing the first Italian brake discs for the aftermarket. Prior to that, discs had been imported from the U.K. Production of brake discs was followed by the development of other braking system components.

The company began to build recognition on an international level, ultimately gaining leadership in Europe’s brake disc aftermarket.

Following a strategy of expansion into specialized vehicle market niches at the beginning of the 1980s, Brembo started developing additional products and technological processes for cars, motorcycles and racing vehicles. Brake calipers for cars have been a part of their product range since 1980 and featured a new-for-the-time choice of material: aluminum. The new aluminum calipers were later adopted by high performance car manufacturers, such as Porsche, Mercedes, Lancia, BMW, Nissan and Chrysler.

Proof of Brembo’s strategy success can be seen in the expansion of the company itself. In 1985, Brembo reportedly had 335 employees, by 1995 the total rose to 1,115 employees, by 2000 it rose to approximately 2,800; currently Brembo has a total of 3,600 employees, with revenue of $644 million.

Brembo has recently expanded its racing distribution throughout North America. CV Products has aligned with Brembo. It’s North Carolina-based operations will carry Brembo brake systems and components for Sportscar and NASCAR with emphasis in Late Model and Oval Touring Racing. The addition of this market distribution point increases the number of Brembo North America distributors located throughout the U.S., enables quicker response to East Coast based markets and will reinforce track side support and service customers needs.

Racing business and success continue to pay off for Brembo. Their storied partnership with Ferrari — that started Brembo’s foray into the racing world — continues to pay off. For the 2002 Ferrari F1 car, Brembo designed a ceramic composite material (CCM) braking system.

The design and the 2002 Ferrari F1 efforts were both huge successes which ultimately led to the alteration of the CCM system to be fit into Ferrari’s namesake supercar, the Enzo.

CCM has a 30 percent weight savings (in comparison to normal cast iron discs) which allows a decrease in unsprung weight and in turn provides heightened dynamic behavior of the car in sporting use.

The composite ceramic material is designed to guarantee a high friction coefficient in all conditions of use. It remains constant when braking at all speeds, allowing the driver to optimize the force to apply to the pedal. The thermal deltas, to which the disc is subject during heavy and prolonged decelerations, do not influence the friction coefficient of the composite ceramic material, which is basically constant. This crucial property is difficult to obtain with traditional cast iron elements.

According to Brembo, the CCM units limit deformation, at high temperatures, ensuring flat mating with the pads. Cast iron discs tend to deform when subject to severe and prolonged thermal stresses. This causes noise and more importantly an inevitable reduction in braking performance.

Technological advances that were made due to the company’s Formula 1 efforts weren’t limited to discs — new calipers were also developed. The calipers are of monobloc type to maximize rigidity and reduce deformation due to the high stresses generated by the pressure of the pistons on the pads. The calipers are worked with a machine tool starting from a block of cast aluminum. Regular production cars feature units consisting of two separate parts that are symmetrically joined.

The front calipers of the Enzo have six pistons, three per side, with varying diameters engineered to guarantee uniform wear of the pads, which would otherwise manifest more quickly on the disc entry edge.

The rear calipers feature a four-piston design, two per side, with different diameters. The pistons have a thermal insulator and are drilled radially near the circumference in contact with the pads to limit the dissipation of heat to the hydraulic system’s brake fluid.

---

How CCM is made

The Formula One-inspired CCM brake (above) is used to stop the Enzo Ferrari’s 660 horses (below).

The Formula One-inspired CCM brake (above) is used to stop the Enzo Ferrari’s 660 horses (below).

Carbon braking bands for competition are typically made using long, resistant carbon fibers woven together and directed flat (two-dimensional) or in space (three-dimensional) in specific and non-random directions.

Brembo CCM discs, use short carbon fibers (chop fibers), arranged randomly in defined sizes and quantities. In Formula 1 discs, the Carbon/Carbon material is obtained from the CVD (Chemical Vapor Deposition) process. This process lasts about 150 days, and the raw materials include carbon fibers and methane, the finished product consists of carbon fibers in a carbon matrix. Raw materials used for CCM discs are made up of carbon fiber, phenol resin and silicon. The fibers and resin are molded in the geometric shape of the braking band. Through a process called pyrolysis, organic substances present in the resin are carbonized and a Carbon/Carbon material is yielded where the fibers are in a carbon matrix suitable for the final silication treatment.

The silication process is called LSI (Liquid Silicon Infiltration). In this phase, the liquid silicon is infiltrated into the carbon matrix and, combining with it, generates silicon carbide (ceramic) by reaction. At this point the disc has reached the necessary resistance to abrasion by the pads, which ensures a life equal to that of the car. This is followed by surface-finishing using diamond-tipped tools. Development of this production process considerably reduces the production times of the rough disc (five days) and is the basis for the future series production of CCM units.