Cutting Edge Corners

Try imagining going round your favourite corner and feeling the car body hardly rolling or moving. This is the reality of Ferrari’s all-new and utterly revolutionary suspension system. The clue to its secrets lies in the name Ferrari has given to it: Ferrari active suspension technology using Multimatic’s True Active Spool Valve (TASV) System. The crucial word here is ‘active’, which describes how the technology works; but it could equally well apply to the Ferrari approach to innovation: always active, always seeking new ideas. 

With no fewer than three fresh patents, the Ferrari active suspension technology is absolutely new and makes its debut in the Purosangue – the most comfortable, most versatile Ferrari ever made. 

Innovative technology means cornering has never been so comfortable. Or so safe 

Head of Chassis Engineering for GT Cars, Alfredo Scifo, is in no doubt about its significance. “In terms of chassis engineering, this is the biggest single technological leap that Ferrari has made in the last ten years,” he says. 

Unlike conventional dampers (which react in a fixed way to road surfaces), Ferrari active suspension technology dampers can move entirely independently of the forces acting upon them. The ground-breaking system includes a motor control module (MCM) sited inside the damper – a world first, and fully patented. Each of the four damper units – one at each corner – is fitted with a smart actuator that can provide force on each damper, individually. 

This force comes from an electric ‘e-motor’ linked to each damper rod. There’s a sophisticated suite of sensors – body accelerometers, wheel accelerometers, wheel position sensors and 6D yaw-rate sensors – that constantly supplies information to define the damper force that is required. 

Vehicle Dynamics Engineer Francesca Mincigrucci, in charge of control software development, tells us: “We have two further patents relating to the control logic software, which permit an infinite range of adjustment. We can now completely control the position of each wheel – we can put each one wherever we want, with full control.”

The active system intervenes to balance the forces acting upon the front and rear axles, individually. This enables very fast changes of balance in each section of the corner. On entry, extra force on the rear axle increases lateral acceleration. On exit, more force is applied to the front. The result? Balance, stability and fun

In terms of ride comfort, a huge amount of work was also done. “The active technology is installed on the wheel so you have to manage extra mass,” explains Francesca. “Using the motor control module to achieve the right level of comfort was challenging.” The system works automatically, although the driver can choose one of three different levels of damping via a dedicated manettino. 

The ability of the Purosangue to cope with rough roads marks a completely new departure for Ferrari. A lot of durability testing was undertaken on uneven paved surfaces. Alfredo recalls one particular experiment the team performed: “We put some plastic drinking cups on the roof and the active suspension’s body motion control kept them steady there. When we turned the system off, those plastic cups no longer stayed on the roof.” 

There were many development challenges. The e-motor was developed entirely from scratch, and it took a lot of effort to engineer a compact unit capable of sustaining forces of up to 6,000 Newtons per corner. The sophisticated system has its own battery and even its own cooling, using two pumps (one per axle) fed by a small radiator.

The four active suspension dampers can move full independently of each other, and each include their own motor - a world first    

Precisely the right materials were chosen for each part of the damper – such as spheroidal cast- iron gears – to minimise noise and vibration. And the active suspension had to be integrated with all the other active systems, such as the 4RMS-evo four-wheel steering system. 

A further vital feature of the Ferrari active suspension technology is that it is completely transferable to other, future Ferrari projects. Francesca says: “It has a lot of potential. The software can easily be calibrated to achieve different performances in different vehicles. In fact, it gives us infinite possibilities, something that was just not possible before.”