As is often the case in the automotive industry, experiments made through competition are then transferred to production cars.

This is the case with the Brake-by-wire (BBW) which with the 2014 F1 Championship saw the light on several crews, not least of course Ferrari.

In F1 the need arose with the adoption of the ERS (Energy Recovery System), the kinetic energy recovery system. When braking, without intelligent control the driver would have to modulate braking according to the varying degrees of ERS intervention and recharging, and clearly this is not at all feasible, all the more so for high performance cars.

It is therefore necessary to make the recharging action of the ERS transparent to the sensitivity of the driver when braking the single-seater; regardless of the amount of energy collected, the BBW system must, in other words, provide the braking balance between the front and rear axles. This is done thanks to an electronically controlled hydraulic system that allows the braking distribution between the axles to change instantaneously as the motor-generator recharges, requiring a commensurate commitment to the discs and calipers.

Another important feature of the BBW is the response time which, thanks to the electronic control, is reduced to just 100 milliseconds compared to the 300-500 of traditional systems, which translates into greater road safety: at a speed of 120 km/h every 300 milliseconds a car travels 11 metres; a shorter reaction time from brake control to actuation of the caliper on the disc can help reduce braking distances by a considerable amount.
On the road and in the specific case of the Alfa Romeo Giulia, a simplified but equally sophisticated BBW is adopted. The ERS system is not present for the time being, but all the peculiarities described above are there.

The braking system is controlled by a standard electronic module called MK C1equipped with 'ABS' and 'ESC' stability control.

The module called MK C1 is present on all versions and is identified on the diagnostic tool by the acronym ABS.

This sophisticated management system is designed in such a way that no servo brake is required.

Under normal operating conditions, in fact, the brake pedal does not generate hydraulic braking pressure directly on the calipers, but it is the system that provides the different responses (feedback) on the brake pedal, thanks to the so-called 'pressure simulator' (4) which has the fundamental task of providing the correct progressivity to the brake pedal.

Electronics in this way generally improve the functioning of the system; for example, when ABS comes into play, the characteristic vibrations on the brake pedal will not be felt as braking pressure is achieved in less time, with the higher pressure value. This leads to improved system efficiency and a significant reduction in braking distance, as well as a reduction in overall dimensions.

The braking system management strategy also includes an important recovery; the brake pedal is connected directly to the master cylinder (3) and is designed to achieve higher pressures than conventional servo-brake applications; this is because in the event of a system failure, the driver must be able to brake the car without exerting too much force on the pedal.

We refer you to the next article, where we will look in detail at the components that make up the module MK C1.

• ABS Giulia
• Alfa Giulia