Bugatti provides details of the recently completed Wind Tunnel Tests of its Centodieci model.
The prototype of the French luxury manufacturer's new few-off hyper sports car remains firmly on the ground. Five bands simultaneously simulate high speeds of up to 300 km/h – one under each tire and the fifth under the vehicle floor. "We use this to simulate the airflows under the vehicle and in the wheel wells, and then precisely tune the Centodieci," explains André Kullig, Technical Project Manager for one and few-off projects at Bugatti.
Bugatti details several aspects of the test. The driveshafts are dismantled ahead of testing to prevent the wheels' external drive from transferring any forces into the vehicle. The vehicle is then fixed with nothing but four small pins in the underbody and its height is varied according to the testing plan.
Every new Bugatti model goes through the complete development process, be it a one-off like the La Voiture Noire or the limited run of ten Centodieci vehicles. "It makes no difference to us engineers whether we are developing a hyper sports car for one, ten or 500 units – the effort is the same, as we have and want to meet, even exceed the quality and safety standards applicable to mass production," explains André Kullig. The flat front construction with the smaller horseshoe shape means the wind flows around the vehicle differently from a Chiron or Divo.
Bugatti, with speeds well above 350 km/h, ensures that the aerodynamics and downthrust of any of its hypercars are correct. Following computer simulation and the prototype rollout, additional wind tunnel tests are performed before a vehicle undergoes high-speed testing on test tracks and proving grounds.
With the prototype in the wind tunnel, the developers make slight changes in the invisible range to edge closer to the desired values. Minute angles can adjust the front diffuser flaps for this, and the rear wing, which will ultimately be in a fixed position, can likewise be modified by just a few degrees. "Even once we have identified the ideal settings, we continue to try others in order to see how the Centodieci responds," says André Kullig.
In the wind tunnel tests, Bugatti's engineers check the airflow on and around the Centodieci at various speeds. Starting at 140 km/h, they use a standard setup to determine a benchmark figure compared to other Bugatti hyper sports cars. They then run various tests up to the test bench's maximum speed. "What's important are the data for downthrust at the front and rear axles. These have to be perfect because they are crucial to the vehicle's handling at high speeds," explains André Kullig. The aim is handling that's as balanced as possible at all speeds from 0 to over 300 km/h.
The temperature of the 8.0-liter W16 engine with 1,600 PS also depends on the side airflow, where the engine and gearbox oil coolers are supplied with air. The engineers also check the high-performance system's brake cooling in the wind tunnel using particular fog images. In further tests, the wind hits the bodywork at various sideways angles to simulate the vehicle's handling when taking corners quickly with shifting loads. "No matter what speed and what driving situation, the Centodieci is sportily neutral and can be managed at all times despite its immense power," says André Kullig. The engineers will clock up many more kilometres on the test tracks and proving grounds over the next few weeks to select the ideal setup.
Bugatti presented the Centodieci within its successful new coachbuilding program in summer 2019. The Centodieci is a homage to the legendary EB 110, with which Romano Artioli revived the Bugatti brand some 30 years ago.