New Ferrari Challenge Stradale: Geneva 2003
Published: 6th March 2003
The Challenge Stradale builds on aerodynamic concepts employed on the 360 Modena by taking advantage of the racing suspension set-up (stiffer more rigid and lower) and adopting specific solutions that have led to a gain of 50% in vertical load compared with the 360 Modena.
The results are extremely significant: at 200 km/h the load increase is about 40 kg for a gain corresponding to the effect of a wing with 15 cm chord length and 1.8 metre span.
Despite such a significant increase in vertical load, after all the modifications and adjustments to set-up, the car has a Cd equal to that of the 360 Modena (Cd= 0.335).
Three? Four areas feature in the types of intervention were adopted to improved aerodynamics ofon the Challenge Stradale.
- Front section: modification of the bumper, which now extends below the air intakes to increase load at the front but without disrupting airflow towards the rear.
- Aerodynamic study of the car's underside and rear section: with the result of an increase in height at the rear and introduction of longitudinal fins to balance the load. The decision was also taken to modify the rear nolder to achieve greater efficiency by adopting a shape more appropriate to the function. concerned.
- Drag and modification of the sills: the new shape sills streamlines the rear wheels more completely and contributes significantly to improving the car's efficiency and balance. The combined result of these changes interventions is that compared with the 360 Modena drag has remained unchanged, so leading to a significant increase in efficiency.
In addition to the changes interventions outlined so far, the focus on the Challenge Stradale's aerodynamics and styling has been enhanced by a painstaking review of all technical details of the project: 360 GT-style aerodynamic, carbon mirrors, new 19" wheels with a Challenge-type design.
Weight Reduction
Careful project development has led to a Challenge Stradale car weight that is fully 110 kg less than the 360 Modena, achieved by concentrating on three complementary areas spheres: materials, construction technology and project optimisation.
The basic material used to build the Challenge Stradale is aluminium, as is was already the case for the 360 Modena and Spider. Aluminium has been used for both body components and, above all, the space frame, a combination of castings, extrusions and plates. This initial approach towards drastically reducing the Challenge Stradale's weight already made it extremely competitive (compared with the 360 Modena) given that the basic material used, aluminium, has a specific weight one third of that of steel.
Starting from this base new developments were introduced specifically for the Challenge Stradale. Titanium, already used for the piston rods, was also adopted for parts of the suspension, in particular for the wheel bolts (a 50% weight reduction) and damper springs (a 27% weight reduction).
Carbon technology, derived directly from Formula 1 and used extensively on Ferrari limited-run road cars, is was employed here for the first time on an 8-cylinder car.
For the Challenge Stradale it has been used for both structural parts (door panels, racing seat shells, filter-box covers) and for interior and exterior trim features.
A particularly advanced construction technology was adopted for the car's floorpan. This involves impregnating the resin with multi-axial carbon fibres in a vacuum in order to obtain the necessary rigidity, but which simultaneously leads to a 50% reduction in the weight of the floorpan itself.
A key factor in the search for the best weight-performance ratio for the Challenge Stradale was adopting a braking system comprising carbon-ceramic (CCM) discs developed for Formula 1 combined with aluminium brake carriers as standard equipment.
In terms of weight, the reduction achieved on the Challenge Stradale as a result of CCMs is 16% compared with conventional brake discs, but given that the weight eliminated affects unsuspended masses, its contribution to the car's performance is can be assumed to be even more significant.
