FACTfile - Alfa GT – Page 3

Cutting edge technology for the gratest safety

The Alfa Romeo GT offers the most modern safety features and equipment to prevent accidents and protect the occupants when accidents happen. In the preventive safety field, the new model offers xenon headlights, its active safety complement includes VDC with Brake Assist for total control of car dynamic stability under all conditions. As far as passive safety is concerned, the Alfa GT offers up to six airbags: two front airbags, two front sidebags and two window bags.

To ensure the Alfa GT offers the greatest passive safety, the Fiat Auto Safety Centre engineers examined all possible types of accident (frontal impact, side impact, roll-over, shunting and fire), taking into account the various speeds at which impact may occur, the different types of obstacle and the need to protect occupants with very different physical characteristics. The result: the new model is one of the safest cars in its entire segment.

VDC with Brake Assist - to ensure absolute mastery of the car under all conditions, however extreme, the entire Alfa GT is fitted as standard with VDC (Vehicle Dynamic Control) with an emergency brake assist device. This is the Alfa Romeo version of ESP, or Electronic Stability Programmes. This innovative device cuts in under extreme conditions when car stability is at risk and also helps the driver control the car. As befits a true Alfa, the VDC is a sporting device that allows outstanding roadholding. It enables the driver to enjoy total mastery of the vehicle while conditions are normal, cutting in only as the situation becomes critical. The VDC is permanently engaged. The MSR (Motor Speed Regulator) cuts in when the gear is shifted down abruptly in low grip conditions. This device cuts engine to prevent the wheel skidding as a result of wheel lock-up. To achieve these results, the VDC continually monitors tyre grip in both longitudinal and lateral directions.

If the car skids, it cuts in to restore directionality and ride stability. It uses sensors to detect rotation of the car body about its vertical axis (yaw speed), car lateral acceleration and the steering wheel angle set by the driver, which indicates the chosen direction. It then goes on to compare these data with parameters generated by a computer and establishes - via a complex mathematical model - whether the car is cornering within its grip limits or if the front or rear is about to skid, either understeer or oversteer. To restore the correct trajectory, it then generates a yawing movement in the opposite direction to the movement that gave rise to the instability by braking the appropriate wheel (interior or exterior) individually and reducing engine power (via the throttle). This is the key attribute of the device designed by Alfa Romeo engineers. It acts in a modulated fashion on the brakes to ensure the action is as smooth as possible (and the drive is not therefore disturbed). The engine power reduction is restrained to ensure outstanding performance and great driving satisfaction at all times. As it carries out its complex task, the VDC stays in constant communication with the brake sensors and engine control unit but also with:

1. a body computer that constantly exchanges information with the ABS, engine management unit and automatic transmission unit
2. an electronic throttle, that communicates with the ABS in turn
3. a control panel, active warning lights
   the steering wheel and steering column via the steering sensor
4. a gyroscopic sensor installed on the passenger compartment floor to record car yaw and lateral acceleration

The VDC fitted to the Alfa GT also comes with an emergency brake assist device. The function is carried out electronically by the ABS control unit and is referred to as EBA (Emergency Brake Assistance). In emergency braking situations, most drivers recognise a situation of danger and press the brake pedal very quickly. But not, however, with sufficient force. This is because people, unless they are professional drivers, are used to applying a certain load to the brake pedal. Because people tend to switch to autopilot mode when they carry out repetitive actions, the same level of force tends to be applied in all circumstances. On the Alfa GT, however, the EBA device cuts in at this point. Although the pressure on the pedal is unchanged, the car is decelerated by the same amount as it would be if it were braked with all the necessary force. And there is more.

Panic brake assist devices can even help experienced drivers who brake quickly and apply the correct amount of force in emergencies. This is because the system reduces braking attenuation time in all cases, the period between the time when pressure begins to be applied to the pedal and the moment when the circuit reaches maximum pressure and is able to offer maximum performance. Front airbags, front sidebags and window bags The Alfa GT offers no fewer than six airbags, all as standard. Firstly the front airbags: for the driver (with capacity of 42 litres) and passenger (90 litres). Their operation is controlled by an electronic control unit on the tunnel that evaluates impact severity by means of sensors that are calibrated by conducting crash tests in the laboratory. Less time than the blink of an eye elapses between a crash and the airbag opening. The gas used to fill the bags is inert, non-toxic argon. The airbags are also made out of nylon 6/6, a permeable material that allows the bag to deflate in a few tenths of a second after impact to minimise skin abrasions. Bag structure is innovative: it is folded in a special way and equipped with two cloth strips that yield gradually to allow the bag to unfold more gradually and not directly toward the occupant. The system comes with a diagnostic circuit for checking components electronically. The components are tested by a processor that monitors their operation continuously. The airbags will not be activated by low speed accidents, for example, a slight shunt or a bump while parking, or by stresses that are not due to impact, such as driving fast over a pothole).

The passenger front airbag may be deactivated manually by operating a switch on the end of the fascia with the ignition key. This means a baby can be carried on a baby seat facing in the opposite direction to the car's motion, but the pretensioner remains active. The Alfa GT is fitted with two sidebags to protect the pelvis and chest of front seat passengers when the car is struck from the side. They are located inside the front seat squabs. This solution ensures the best possible protection for passengers regardless of their stature, sitting position or seat setting. For geometrical reasons, it is also possible to use a 12 litre airbag: this volume is lower than an airbag housed in the door would require to offer the same protection. The sensors controlling activation of these airbags are located in the central pillars. If an accident occurs, they receive a side acceleration signal and send it to the electronic control unit that is also responsible for operating the front airbags and seat-belt pretensioners. All systems are managed in an integral manner in accordance with a strategy of total, progressive occupant safety.

The Alfa GT is also fitted with window bags that drop down along the windows to safeguard the passengers' heads in the case of side impact. Compared to other solutions, the window-bags adopted on the Alfa GT are more protective (because they always take up the correct position), faster to inflate and less invasive for passengers. They open from top to bottom and do not involve a risk of secondary damage to occupants' arms. They also effectively safeguard the heads of front and rear passengers because they extend along the entire width of the window and ensure protection even during rollover. Two bags (one on the right and the other on the left) are located under the roof rails where they are folded into a closed compartment. At the appropriate moment, the covering bends open to allow the bags to expand and drop downward.

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