Middle East - The secrets of Alfa Romeo driving dynamics

• The secrets of Alfa Romeo’s famous driving dynamics were revealed for the first time at an original event held at the Balocco Proving Ground in Italy, combining technical workshops and specially designed driving sessions

 

• The event was a journey of discovery into the most innovative, exclusive technological solutions that make the driving experience on board the new generation Alfa Romeo models even more thrilling.

 

• There was a special focus on all-wheel drive with Q4 technology, designed for real-time management of the vehicle's grip on the road, plus the Integrated Brake System, which significantly reduces braking distance on any surface.

 

• Also covered were Torque Vectoring - which provides unbeatable traction control - and the exclusive AlfaLink^TM suspension architecture that delivers superlative handling, supported by flawless weight distribution and excellent weight/power ratios.

 

For the first time, Alfa Romeo revealed the secrets of its renowned driving dynamics through four in-depth technical workshops and track sessions staged at the FCA Group’s Experimental Centre at Balocco in Italy. The unique programme, specifically designed to demonstrate and actively test Alfa Romeo’s technological solutions, clearly illustrated how they combine to make driving the Giulia sports sedan and the Stelvio premium SUV even more of an exhilarating experience, especially when applied to the most powerful Quadrifoglio versions.

 

Significantly, the Giulia Quadrifoglio and Stelvio Quadrifoglio, both at the cutting edge of Alfa Romeo design, were the first to feature these sophisticated systems which were subsequently extended across the entire range. This top-down approach, unique in the automotive industry, is at the core of the Alfa Romeo spirit - a globally exclusive formula that combines the right balance of Italian design, state-of-the-art engines, flawless weight distribution, unique technical solutions and an excellent weight/power ratio in every one of its mechanical creations.

 

Getting into a Giulia or Stelvio means entering a new dimension, where the focus of these mechanical masterpieces is the driver, his emotions and his desire for a thrilling driving experience - a principle reflected in the precise steering, responsive throttle and immediate responsiveness of the transmission and brakes. Not to mention the choice between rear- or all-wheel drive, which is more than merely a tribute to the most authentic roots of the Alfa Romeo legend; it is also a technical solution that ensures high performance and astounding driving pleasure. This makes the breath-taking driving experience delivered at the wheel of an Alfa Romeo a welcome surprise for even the most highly skilled, demanding driver.

 

The workshops and driving sessions that revealed the secrets of Alfa Romeo’s renowned driving dynamic were organised into four workshops discussing in depth, the degree of innovation of the all-wheel drive with Q4 technology which is designed to control of the vehicle's traction both reactively and predictively, to deliver the very highest levels of performance, efficiency and safety. 

 

In simple terms, the Alfa Romeo Q4 system provides all the advantages of all-wheel drive, plus excellent fuel economy, responsive performance and all the driving pleasure of a rear-wheel drive vehicle. The Q4 all-wheel drive versions can also be integrated with a Q2 mechanical self-locking rear differential, which is available on request on versions with rear wheel drive only. The self-locking rear differential further accentuates the agility and sporty nature of the Giulia and Stelvio, ensuring perfect traction for an unforgettable driving experience.

 

The event also focused on another Alfa Romeo brand exclusive system - the Integrated Brake System (IBS), an electromechanical system that combines stability control with a traditional servo brake to deliver instantaneous braking response, thus shortening stopping distances, while also making a significant contribution to weight optimisation. The braking system is also available with carbon ceramic discs on Quadrifoglio versions.

 

There has also been great interest in the Alfa™ Active Torque Vectoring system, a state-of-the-art technological feature designed to achieve the best performance of a sports car. In detail, the two clutches in the rear differential make it possible to control torque delivery to each wheel separately, so power is transferred to the ground more effectively, even when the car is driven to its dynamic limits. This makes the car safe and fun to drive at all times, without ever needing any intrusive intervention from the stability control system. Alfa™ Romeo Active Torque Vectoring, like all the other active control systems, is overseen by the Chassis Domain Control: a unique central vehicle “intelligence” that Alfa Romeo created with its own algorithms to harmoniously - and in real time - handle all the electronic devices that are involved in the car’s behaviour, making driving extremely natural, instinctive and safe.

 

Finally, the four workshops shed light on the sophisticated suspension systems - the most evolved in the segment. Alfa Romeo’s exclusive Alfa™ Link, features a double wishbone suspension with a semi-virtual steering axis at the front - this optimises the filtering effect and lets you steer quickly and precisely. At the rear, a multilink solution with four and a half arms was opted for - this Alfa Romeo patent ensures enhanced handling combined with excellent comfort. The suspension set up enables the system to be very rigid when cornering and at the same time very flexible in the longitudinal direction.

 

Furthermore, active suspensions are available on request. Alfa™ Active Suspension, with an electronically controlled damping system, adapts to driving conditions instant by instant, enabling the driver to opt for more performance-biased or comfort-oriented handling. Another factor in superlative driving pleasure is the flawless weight distribution between the two axles and an excellent weight/power ratio, achieved through the use of ultra-lightweight materials such as carbon fibre for the driveshaft throughout the range. 

 

Alfa™ Link patented suspension and vehicle dynamics 

 

Driving an Alfa Romeo is an unmistakable, unforgettable sensation. This is thanks to a unique suspension scheme. At the front, a double wishbone suspension with a semi-virtual steering axis lets the driver steer quickly and precisely, thanks to perfect tyre grip on the track and a strong sensation of control. At the rear, Giulia and Stelvio are equipped with the new Alfa™ link, an aluminium multilink scheme.

 

When designing vehicle suspension systems, the essential features involve safety, comfort and optimisation of NVH (noise, vibration and harshness). For an Alfa Romeo, however, this is not enough - the driver must feel a thrill, and he can, thanks to Alfa Romeo’s search for an exclusive steering feeling, with high definition and performance without compromise. This is why the Alfa Romeo team has put so much work into the entire Giulia and Stelvio range, starting with the Quadrifoglio versions. This also lets the less powerful engine versions benefit from the technology perfected for the more extreme models.

 

Front suspension: Alfa Romeo patented structures and solutions

 

The objectives that led the suspension design phases have maximised handling and comfort performance, creating an unmistakable, unforgettable steering feeling and preventing steering wheel reactions caused by the engine torque on the Q4 versions. Achieving these objectives meant selecting a double wishbone suspension with a semi-virtual steering axis instead of a McPherson - in fact this ensures more suspension angle controllability, which is needed to better take advantage of the tyre characteristics and thus ensure maximum road grip. The Alfa Romeo Giulia and Stelvio double wishbone suspension with a semi-virtual steering axis comprises:

 

1. An upper control arm

2. Two decoupled lower links (handling and comfort link)

3. A tie-rod steering arm

4. A co-axial spring and shock absorber group

5. A hollow aluminium knuckle

 

The unique feature of the front suspension is in the fact that there are two separate lower levers, hinged to the strut differently. This double lower link (an Alfa Romeo patent) performs a “scissors” movement that maintains the linear steering feeling in all conditions. Results like these simply cannot be achieved with a conventional suspension with a single lower link.

 

This solution ensures full control of the longitudinal arm on the ground depending on the suspension direction - it optimises steering speed and precision in all types of conditions, guarantees the typical Alfa Romeo central driving feeling, and ensures a linearity of response to the upper limits that can be used in total safety. A high definition steering feeling that has no equal.

 

The electric power steering, with the motor fitted on the rack, together with an extremely direct steering ratio (12:1), has been designed to work in harmony with the suspension characteristics and guarantee torque linearity to the steering wheel across the entire lateral acceleration range.

 

Compared to our competitors, the adoption of a high wishbone suspension instead of McPherson allows us to achieve higher performance in terms of handling and ride comfort, but at the same time this choice involves higher costs and more suspension parts. In order to decrease weight, all components are made from aluminium, and on some components, the manufacturing technology has evolved into hollow or forged aluminium.

 

Rear suspension

 

A multi-link solution with four and a half links was chosen for the rear axle. This patented Alfa Romeo scheme, called Alfa™ Link, ensures extremely precise control of the characteristic wheel angles, which translates into road behaviour at the top of its category, with excellent handling combined with outstanding comfort. The suspension scheme enables the system to be very rigid on corners and at the same time to be very flexible in the longitudinal direction. The filtering of uneven roads is very good, also courtesy of the use of elastic connections with hydraulic damping.

 

Toe adjustment can be done using a patented device which allows the hardpoints of the suspension to remain unchanged even when changing the toe and camber is necessary. This solution does not change the elasto-kinematic behaviour of the suspension, even if it is necessary to adjust the static angles - the same thing does not happen using the conventional solutions found in other cars.

 

The longitudinal dimension of the suspension is the most compact in the segment. This feature allows an increase in the space available for the rear seats without increasing the size of the car and keeping a wheelbase aligned to the size of the segment. The suspension components are made using high-strength materials - 45% are made of aluminium to reduce the weight of the wheel assembly and thereby optimise comfort, while the lateral stiffness of the suspension is the maximum in the segment.

 

All-wheel drive with Q4 technology

 

A mountain hairpin, a gravel road, a snowy surface, cornering on wet tarmac - enjoy effective driving and exploit the unique agility and power of the new Alfa Romeo range with full confidence thanks to the Q4 proactive All Wheel Drive system.

 

Q4 delivers all the advantages of all wheel drive without compromising the driving fun of a rear-wheel drive vehicle, its unique thrills and superior driving dynamics.

 

At the heart of the Q4 system is the Active Transfer Case (ATC) which monitors grip conditions and driver inputs in real time to ensure the best performance and, whenever needed, can transfer up to 50% of the engine torque to the front wheels via an extremely compact, lightweight front differential.

 

To combine maximum safety with maximum performance in every driving situation, from racetrack to snowy roads - this ambitious goal inspired the development of a proactive, on demand all-wheel drive system designed to challenging specifications, whose control strategies, internally implemented by the Alfa Romeo team, enhance the vehicle’s sporty attitude and driving pleasure.

 

Mainstream solutions in the segment are mainly based on permanent AWD systems with low dynamics, biased to a fixed torque distribution value (e.g., 70% Rear, 30% Front in normal conditions) and, once one of the axles starts slipping, the speed difference between the axles leads to a different torque distribution value between front and rear axles (e.g., 50% Rear, 50% Front) purely achieved by mechanical means.

 

Instead, Alfa Romeo’s Q4 system allows the vehicle to travel as a pure rear-wheel drive and, if tyre grip  is approaching its traction limit, or in the case of high dynamic manoeuvres, can instantly deliver up to 50% of engine torque to the front, thus preventing wheel slip and ensuring maximum vehicle performance and driving effectiveness.

 

Torque distribution is then constantly modulated with high dynamic and extreme precision according to the effective traction conditions and driver commands. This translates into best in class vehicle control in terms of traction and directional stability when cornering. 

 

The Q4 system ensures that traction is used to max out the performance in any condition, increasing vehicle handling, and, if needed in extreme conditions, stabilizing it before the intervention of the brake or electronic stability control without any negative effect on performance. 

 

Of all “on demand” all-wheel drive systems, Q4 represents a generational leap - enthusiasts have always known that traditional AWD vehicles tend to understeer. But with Q4, Alfa Romeo’s sporting heart beats at a different rhythm in every configuration of the DNA selector, creating the maximum emotional involvement when in Dynamic configuration. With traction control designed by the Alfa Romeo team, you drive a car that gives you the pure driving feeling of rear-wheel drive plus the maximum safety guaranteed by having traction available on all the four wheels.

 

In order to further enhance vehicle dynamics and handling, Alfa Romeo has opted for a unique feature within its Q4 System - different transmission ratios between the front and rear axles. Even on variants without staggered tyres, this allows the vehicle to come out of a corner faster thanks to early vehicle stabilization (up to -0,5s -v- the best competitors in a 50m radius corner driven @70km/h). So driving out of a corner becomes faster thanks to the ability to accelerate earlier than an all-wheel drive vehicle without this feature, meaning using identical transmission ratios in front and rear axles.

 

To be able to offer this level of performance, the entire system has been designed with challenging, innovative specifications. The active transfer case (ATC) was designed to rapidly and accurately adjust the amount of torque sent to the front axle, instantly modifying it according to the traction progress, to the driver’s requests and to the vehicle’s dynamic behaviour.

 

Reaction times are a reference point in its class - the system can send almost 1000Nm to the front differential pinion in under 150ms, and decrease from 1100Nm to 100Nm in barely 120ms.

 

Q4 can withstand intensive use, e.g., driving to the max on a race track or on low grip surfaces, dissipating very high energy in the clutch assembly without adding external cooling systems. This is a unique feature in the market, one that is able to guarantee extremely dynamic, long-term driving without overheating.

 

The Alfa Romeo Q4 active torque distribution system (Active Transfer Case or ATC) also has unrivalled input/output torque levels in its class, and is capable of handling up to 5000Nm input torque from the transmission and deliver (ratio 1:1) up to 1200Nm to the front axle pinion via a chain transmission that ensures quiet, efficient reliable operation thanks to its pumpless design.

 

This unique clutch operation strategy, enables pure RWD driving in normal conditions and allows for high efficiency and reduced fuel consumption in comparison with other AWD solutions on the market.

 

A little masterpiece, the Alfa Romeo Q4 front differential unit is extremely compact and lightweight. It is also very efficient thanks to specific design elements that have been designed to reduce drag losses to a minimum.

 

The overall weight increase of the AWD System, including the front side shafts, is less than 50kg with oil, an absolute reference value.

 

Q2 mechanical self-locking differential

 

Q4 all-wheel drive versions can be integrated with a mechanical self-locking rear differential, which is also available on request on versions with rear-wheel drive only. The self-locking rear differential further emphasises the agility and sporty nature of the new generation Alfa Romeos. The differential, designed with a 1.5-way clutch pack, pressure rings and no preload, guarantees prefect traction in all conditions for a fluid driving experience. 

 

The Q2 mechanical self-locking differential accentuates the vehicle’s agility, letting you use it in utmost safety. The system ensures:

 

• Enhanced driving performance with locking differential
• Greater vehicle stability in curves at high speed and higher side acceleration
• Increased vehicle traction even in differentiated grip conditions on the axle
• Extraordinary stability and control when driving straight in all grip conditions
• Top safety levels in wet or slippery road conditions by keeping the wheels constantly in check and reducing slippage

 

Chassis Domain Control, Torque Vectoring and active suspensions

 

All Alfa Romeo vehicles have been designed to achieve the best dynamic performance and deliver a unique driving experience. To ensure this, platform development followed these guidelines - 50/50 weight distribution as basic, plus design and maximum lightness.

 

The starting point was to research passive vehicle excellence - suspensions, steering, differential, brakes. However, this does not guarantee unique performance in its class. A “brain” is needed to command and manage the entire control system and on-board equipment, from active suspension to torque vectoring - all of these elements are coordinated by the Chassis Domain Control, designed by Alfa Romeo with proprietary algorithms.

 

This is the car's “second brain” (in addition to that of the driver) - a single central intelligence unit that harmoniously oversees all the electronic devices that intervene in real time on road behaviour, making driving extremely natural, instinctive and safe.

 

Alfa Romeo’s philosophy is that active systems must not distort the response of refined mechanisms, but provide the necessary support to deliver the best performance in maximum safety in all driving conditions.

 

Alfa CDC

 

Developed in collaboration with Magneti Marelli, the Alfa^TM Chassis Domain Control (CDC) is the "brain" of the car that coordinates all on-board electronics - it handles interventions of varying types, from the DNA driving system to torque vectoring, Q4 all-wheel drive to active aero splitter and active suspension. And it assigns each of them a precise task to optimise performance and driving pleasure.

 

The CDC unit in particular orchestrates all of the car’s active systems in real time based on acceleration data and yaw detected by the sensors, ensuring utmost performance in all conditions and in safety. It also prevents and manages critical situations, informing in advance the specific control units involved in the vehicle's electronic system: chassis, powertrain, suspension, braking system, steering, assistance and cornering differential.

 

In Alfa Romeo’s technical culture, the control systems have to play a secondary role to style and not “get in the driver’s seat” instead of the person already there. They have to improve the car’s mechanical excellence and not correct its mistakes.

 

All these systems and their related proprietary control strategies have been designed and implemented with the specific goal of them not being invasive and reaching unique levels of performance and control. On an Alfa Romeo, the driver is the one who always decides, and that is why Alfa Romeo continues to believe in cars and in the pleasure of those who drive them.

 

Chassis Domain Control, developed by Alfa Romeo with proprietary algorithms together with a distinctly sporty aspect, has brought this philosophy to Giulia and Stelvio at the top levels.

 

Torque Vectoring

 

One of the most advanced technological features developed by Alfa Romeo engineering team is the Torque Vectoring system.

 

This system allows the rear differential to vary the power to each wheel, improving traction and performance. This technology guarantees fast steering reaction and excellent tyre stability, even at high speeds and in extreme weather conditions.

 

The system comprises two electro-mechanical clutches integrated into the rear differential - this enables the system to distribute the torque mechanically to each of the two rear shafts independently, simplifying driving even in difficult weather conditions. Thanks to the interaction with the CDC (Chassis Domain Control), this system improves the car’s agility, safety and traction.

 

Torque Vectoring optimises the car's agility thanks to:

• Increased maximum lateral acceleration and speed limit
• Compensation of the tendency to understeer 
• Improvement of vehicle response to driver commands

 

Guaranteeing maximum safety all the time:

• Improved stability
• Assists the driver in critical situations
• Stabilises vehicle behaviour
• Supports the driver to keep full vehicle control

 

The Alfa Romeo team developed the Torque Vectoring control strategies based on extensive use of the most accurate and advanced virtual simulation tools and simulator driving sessions, then completed the development with extensive testing that included the most varied conditions of use and grip. All this allows a 4% increase in lateral acceleration, 17% in understeering reduction and about a 20% increase in agility at the same time.

 

Last but not least, the effect on the vehicle performance is maximisation of tyre performance in terms of grip - the forces produced by tyre/road interaction are maximised thanks to Torque Vectoring.

 

Active Suspension

 

Thanks to a high-level control strategy integrated into the CDC unit, the active suspension absorbs shocks not only in proportion to the speed (as in a passive shock absorber) but also in relation to the DNA selector position and road conditions.

 

DNA in N: The “Natural” position delivers improved handling compared with passive shock absorbers. At the same time, the vehicle feels softer and more comfortable when driving on uneven roads.

 

DNA in D: The “Dynamic” position delivers improved handling, while comfort is not affected compared to regular conditions. 

 

Controlled shock absorbers, available on the Quadrifoglio versions and an optional on all other versions, further reduce dynamic pitch when braking and the Skyhook control calibration minimizes dynamic roll gradient and body oscillation

 

Intelligent Braking System

 

Since the beginning of its history, Alfa Romeo vehicles have always been characterised by a sporty DNA dedicated to racetracks and racing. The customer who drives an Alfa always has the feel and awareness that he is driving a high-performance vehicle that differs from its direct competitors because of its higher level of sportiness. 

 

How did this happen? Through a top-down type of development system, where the best performing car in the range, the Quadrifoglio, is the reference point for the versions with less powerful engines. To achieve top performance in braking, we worked on two of the braking system’s main components: the basic system and the actuation system. Alfa Romeo engineers worked during the entire development process to integrate the two systems and maximise their performance. The two main braking system components are as follow:

 

The Brembo-based system

 

In order to maximise reduction of unsuspended mass, the entire Alfa Romeo range has a front axle braking system with aluminium calipers. Compared to the traditional cast iron floating caliper, the aluminium one weighs about half of the total car’s mass; the reduction in the unsuspended mass contributes to improvement in wheel-road contact. The aluminium caliper design is the product of an optimisation process with the following objectives:

 

• Least material for maximum caliper body rigidity
• Design optimisation to ensure the comfort features
• Design: the aluminium caliper gives the car a sense of sportiness

 

In particular, in applying the range to face the demands of compactness and rigidity, totally new calipers were developed, starting with a blank page and a subsequent development and optimisation process.

 

For the Quadrifoglio applications, we pushed things even further beyond the braking system. To achieve targets that were pre-set at the start of the design process in terms of weight and performance on the track, aluminium calipers were adopted for both the front and rear axles. Extreme use on the track resulted in the development of a carbon ceramic system for both the Stelvio and Giulia, taking advantage of the car’s dynamic to the max. The carbon ceramic discs not only ensure greater stability of the friction coefficient even at high temperatures, but also contribute substantially to a reduction in car mass - compared to cast iron discs, the CCM weighs about 5kg less, for an overall saving of 20kg. 

 

Extreme use for braking performance not only comes from the brakes but also from their integration with other systems. Maintaining the system at lower temperatures means that the car can get the most out of its dynamic capabilities and raise its duration limits on the track. To achieve this objective, the front aero splitter (active aerodynamic), in addition to generating downforce, has been designed in such a way that the air flow generated, combined with relevant heat shield geometry, conveys additional flow in addition to normal convection, which helps prolong the system’s life and efficiency.

 

Brake by Wire: IBS activation system

 

The main innovation Alfa Romeo introduced to the range is the Continental MKC1 brake by wire system. 

 

The new activation system was a world premiere in the automotive sector, and at currently no other car in production comes with this system. Its main advantages are:

 

Packaging: Using this system means a notable reduction in the number of components inside the engine compartment, with just one single unit comprising pump, power brakes and ESP. Apart from being consistent with the philosophy of reducing mass, which guided the Giorgio project from the very beginning, reducing the number of components allows everything to be more compact inside the engine compartment, guaranteeing less cantilevered mass, thus making the car more agile.

 

 Weight: the pump, power brake and ESP unit weigh a great deal less than the MKC1 (ca +50%)

 

Pedal decoupling from the braking system: the brake by wire system decouples the brake pedal from the hydraulic circuit of the callipers. The main advantages resulting from this solution are:

 

Tuning the brake pedal feeling: the brake pedal feeling is the way the driver senses the car's ability to slow down. In traditional systems, the rules of the road, the load and deceleration were achieved by balancing the system’s HW components (caliper pump and power brakes) with the limit of being variable with temperature and independent of speed. In the brake by wire system, the feeling in terms of load is achieved through a simulator that can be completely customised. The response in terms of slowing down becomes one calibration that can be optimised according to the driving conditions - a less aggressive pedal feeling makes for relaxed driving in traffic or a more aggressive feeling in track driving conditions. This increases the flexibility of the system and its usage capability.

 

Stability of pedal feeling when used for sport: with the brake by wire system, the pedal length can be shortened when connected to the system and subjected to extreme overheating on the track, where normal applications are subject to a progressive increase in pedal travel.

 

Increase in performance: pressure is generated through a linear actuator, allowing a pressure gradient and much lower wheel locking times compared to traditional systems. This feature translates into optimum control of the wheel dynamic, with a resulting drastic reduction in braking distances.

 

The Alfa Romeo brand's partners for the Balocco Proving Ground event

 

For the Accademia Di Guida, Alfa Romeo joined forces with some of the brand’s partners that are leaders in their respective sectors, for an even more thrilling driving experience.

 

These include Sparco, leader on circuits and courses worldwide since 1977, and the current supplier of sports car seats and carbon fibre components for the Giulia and Stelvio Quadrifoglio versions, with its products leading the “welcome kit” for NRING series customers, along with Pirelli, one of the OEM tyre suppliers for the Alfa Romeo range and sole supplier for the Quadrifoglio versions.

 

Special mention must also be made of the professional driving instructors of the Andrea de Adamich International Safe Driving Centre who, after a short theory session conducted by the vehicle’s designers, held exciting circuit driving practise sessions which were carefully designed and conceived to highlight the effects of Alfa Romeo’s technical solutions on the dynamics of driving the cars. An original, enjoyable way of really getting to know their state-of-the-art technologies in the field. Founded back in 1991, the partnership between the Safe Driving Centre and Alfa Romeo has created courses that have always been up-to-date and tailored to participants' needs, with a strong emphasis on safety, prevention and responsible road use.

 

Finally, also present at the event was Car Shoe. Founded in 1963, the company developed the Alfa Romeo Quadrifoglio shoe, a model inspired by race boot design. First presented in 2017 to coincide with the launch of the Alfa Romeo Stelvio Quadrifoglio, the Alfa Romeo Quadrifoglio shoes are made from leather and hi-tech fabric and feature a special sole that provides a good grip combined with driving sensitivity and are personalised with the name “Alfa Romeo” and the historic “Quadrifoglio” four-leaf clover, both of which are clearly visible and recognisable on the shoe.