Cars

Sixty years after the inaugural race victory for a mid-engined Ferrari sports car, the marque’s first-ever PHEV is once again breaking new ground with an innovative chassis. Time for the SF90 Stradale – and the experts of Maranello’s ‘Body-in-White’ department – to take a bow
Words – Richard Bremner

The pinnacle of the Ferrari range is the most powerful road car the Prancing Horse has ever built, the SF90 Stradale.

It is a beautiful thing to behold but, intriguingly, much of the essence of this fascinatingly advanced car is not visible from the outside.
Under the skin is of course the new mid-mounted 4.0-litre eight-cylinder engine and three electric motors, which together generate the headline 1000cv, but there is another hidden innovation…

‘This is the best component in the car. It’s very beautiful, like a sculpture,’ says Andrea Baldini, head of the department known as ‘Body-in-White’, industry parlance for a bare, unpainted bodyshell.

He’s talking in revered tones about the carbon fibre that is integrated deep within the SF90's body structure, a first for a regular production Ferrari. ‘It’s a one-piece casting, between the shock absorber towers, to support the gearbox. And you can see it only on a naked chassis.’
It’s yet another groundbreaking facet of the SF90 Stradale, the most technically dense road car that Ferrari has ever made. ‘There are over 1000 more components than there are in the F8 Tributo, yet this car has the same length and wheelbase,’ says Davide Abate, Head of Technologies.

The SF90 Stradale’s ‘body-in-white’ is the first of a new spaceframe family. Over time, there will be three Ferrari sharing some of the SF90 Stradale’s modular hardware, although this model is the most complex of the trio. To this end the body ‘uses new materials to push performance to the maximum,’ Abate explains.

Several carbon fibre panchette await mounting within the mixed-material mid-engined chassis Photo credit: Mattia Balsamini

The biggest novelties in the SF90 Stradale’s structure are to be found under and behind its seats. The battery pack is mounted within an aluminium case beneath the car’s occupants, and just behind that is a structure known as the panchetta, an immensely strong crossbeam that forms part of the bulkhead between the cabin and the engine compartment. Both this crossbeam and the bulkhead are made from carbon fibre.

‘It’s the first time we have used carbon fibre in the body of a regular production Ferrari,’ says Baldini. ‘It saves 4kg compared to an aluminium piece,’ as well as providing immense strength in case of a side impact.

After the aluminium body is created at the famous Scaglietti body plant, it is transferred to the Maranello production line where the carbon fibre panchetta is installed in the Ferrari SF90 Stradale Photo credit: Mattia Balsamini

It is a hard-won 4kg, though, as although the carbon fibre section is installed at Maranello, the body-in-white is largely first created at the famous Scaglietti body plant in the nearby city of Modena. ‘It’s a big challenge to fit this carbon part because it’s installed after the body has had its cataphoretic dip,’ says Baldini.

The installation is complex, as Andrea Antichi, Head of Assembly, explains: ‘Structural glue is applied automatically to each individual car. The carbon fibre panel is then secured with bolts, each one tightened to specific torque figures.’ The bolts are attached by hand, and then checked not only for the correct torque but for the angle at which the bolts enter their holes.

‘There are two main characteristics in the assembly of a Ferrari,’ says Baldini. ‘The handmade element is connected to our identity. And there are very high technical standards that must be repeatable.’

Once glued and mounted in the body-in-white, the panchetta is locked into place with bolts torqued to exacting specifications Photo credit: Mattia Balsamini

The manual approach is perhaps seen at its most artful inside Carrozzeria Scaglietti, before the SF90's aluminium body-in-white reaches Maranello for its marriage to carbon. Here, technicians search for any imperfections by running an expert bare hand across the metal’s surface, and employ traditional manual tools for the rare occasion a correction is needed. Yet the process of actually attaching the aluminium panels to one another is very high tech.

‘We use cold joining solutions rather than welding, for strength, the SF90 Stradale featuring no less than 420 of these rivet-bonded connectors, which is over 50 per cent more than for the F8 Tributo,’ explains Abate. This is complemented by some 30 metres of welding to produce a bodyshell that is 40 per cent stiffer in torsion and 30 per cent stiffer in bending than the F8, making it the stiffest-bodied regular Ferrari production car yet.

Those innovations, together with the carbon fibre panchetta, ensure that sixty years after the first mid-engined Ferrari sports car won at the Targa Florio, the beauty still runs deep.