Ferrari’s latest model, the limited edition LaFerrari, featuring a Formula 1-derived carbon fibre chassis and bodyshell and a hybrid powertrain, has made its debut at the Geneva Motor Show.
To attain the performance goals set for the LaFerrari, Ferrari drew on the Scuderia Ferrari Formula 1 (F1) team’s experience in the choice of materials, design and engineering, but also brought in the expertise of Rory Byrne, the F1 designer responsible for 11 of Ferrari’s World Championship-winning cars.
A group of GT and F1 engineers designed a chassis which would provide maximum rigidity and minimum weight, despite the constraints imposed by incorporating the hybrid (V12/electric motor) system. During the engineering phase a number of functions were integrated within the chassis design to reduce weight. One example is the seat structure, which is part of the chassis, lowering weight and ensuring a more compact architecture and a lower centre of gravity.
The result is a significant improvement in performance characteristics over the chassis of the Enzo Ferrari, with torsional rigidity increased by 27% and beam stiffness up by 22%, while weight has dropped by 20%.
The chassis is built in-house in Maranello alongside the F1 cars using the same materials and production processes. As in F1, aerospace prepregs are employed: four different types of carbon fibre are used because each area of the ‘body-in-black’ is engineered to meet specific functional requirements.
Most of the tub is made of T800 carbon fibre, with both fabric and unidirectional (UD) tape being laid up by hand. T1000 UD tape and fabric is used in areas important for passenger compartment protection, such as the doors and the sills, where its high energy absorption characteristics pass the strictest side-impact legislation. Structural elements of the body are made using M46J UD tape and fabric which is extremely rigid, but lightweight. For the underbody, carbon fibre is combined with Kevlar® aramid fibre to protect the carbon structure from road debris damage.
Ferrari reports that this ‘multi-material approach’ was adopted for the entire body-in-black in order to reduce the number of components and lower weight. For example, the one-piece rear section is a single piece hand laid-up using a combination of M46J and T800 carbon fibre to obtain a very lightweight, yet rigid structure.
The carbon fibre composite is cured in the same autoclaves used for the F1 chassis in two phases between 130°and 150°C using vacuum bags to remove any voids in the laminate. The LaFerrari will have a maximum speed of over 350 km/h and acceleration of 0-100 km/h in <3 seconds.