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Chassis

The chassis was built entirely of carbon fibre and aluminium honeycomb sandwich panels, which made it possible to meet demands for outstanding rigidity, lightness and safety. In order to pass the offset collision tests required by the latest safety standards (56 km/h impact), highly sophisticated CAE methodologies were adopted to optimise the composite structures, to identify the optimal bodyshell structure, and to maximise the contribution of the reinforcement skin, where it is needed to support the basic panelling. The final result already meets the stricter future standards which will raise the collision speed to 60 km/h.

Respect for the styling and access targets (door solution with impact on the roof of the chassis) and the goal of passing 64 km/h offset collision tests with a view to further evolution of the requirements (extremely demanding in structural terms as a result of the 30 % increase in kinetic energy to be dissipated compared to previous collision standards), required complex planning of the tooling and the manufacturing methods.

The use of CAE optimisation methodologies was extended to the engine support frame, and particularly to the distribution of thicknesses in the suspension casting. In line with the work done for the bodyshell, a specific analysis set-up made it possible to identify the best weight-performance trade-off, supplying exact indications for the distribution of casting thicknesses.

Experiments confirmed the validity of the solutions chosen: torsional rigidity proved to be higher than the project target and to correspond to the values calculated, while all the homologation collisions gave a positive result from the start.

These results are all the more significant if we consider that the chassis weight had also been decreased considerably to 92 kg (compared to the 102 kg of the composite chassis of the earlier F50).

Suspension and Wheels

The Enzo has independent front and rear suspension with jointed double wishbones, and antidive-antisquat geometries to limit pitching during the transfer of longitudinal loads. The front uspension, which is push-rod in type with an opposed damper, also incorporates a lift to increase ground clearance during parking maneuvers. The rear suspension was designed to adapt to the chassis, with the engine-gearbox-differential assembly supported elastically, and a rear subframe.

Combined with this suspension layout, an adaptive set-up was adopted for the Enzo project, based on a system of continuous control of the damping effect. The adoption of this system on the vehicle makes it possible to reconcile handling requirements (i.e. roadholding, minimal variation of the ground load) with the demands of comfort (movement and acceleration of the "shell", vibration transmitted to the driver), without having to adopt passive solutions (standard dampers) as a compromise.

In other words, electronic adaptation of the damping effect makes it possible to use a damper setting that is sufficiently comfortable in the car's basic configuration ("Sport" setting), yet there is also a setting that offers extra control in high performance conditions ("Race" setting).

The system uses the unsprung weights (wheels and suspension) to hold the sprung weight still (body) but it also insulates the shell from impulses transmitted to the wheels by the ground. The system is actually made up of four sensors (accelerometers) on the shell, two vertical wheel sensors, one vehicle speed sensor and a brake switch. The dampers are fitted with an internal proportional valve governed by the control unit, allowing damping to be modified instantly.

The braking torque control strategies (via ABS/ASR) were specially developed on the basis of the installed power and the optimisation of the braking system, and achieved a satisfactorily convenient result in terms of torque and braking pressure.

Although the Enzo project put the emphasis on handling, because of the car's extreme connotations, the adaptive set-up system employed meant that a good level of comfort could be obtained. Where the wheel modules are concerned, single-bolt light aluminium alloy wheels were chosen. The tyres were developed specifically for the Enzo project by Bridgestone and bear the exclusive name "Bridgestone Potenza RE050 Scuderia".

In order to maximise running safety, the car is equipped with a system that measures tyre pressure through special sensors inside the wheel rims, near the inflation valve. These sensors transmit a signal which is picked up by the antennae behind the stone traps on the bodyshell and linked to the control unit of the pressure monitoring system, which transmits the state of the tyre pressure to the instrument panel.