Should sports-car racing's top dogs be grounded for safety?
By Mike SpinelliPosted 06.04.2008 at 11:16 am2 Comments
The run-up to the annual 24 Hours of Le Mans endurance race is always a nail-biting enterprise for race teams. Naturally, techs are most concerned with assuring cars' ability to sustain the day-night race, which is the ultimate test for GT cars and sportscar prototypes that will wind through the Circuit of the Sarthe -- on a combination of racetrack and public roads -- in Le Mans, Sarthe, France. This year there's an added kink keeping teams up nights. It appears the gods of aerodynamics have been sending LeMans prototype-class racecars into the ether with a cosmic finger flick.
What makes a racecar spontaneously rip a 360 backflip? A perfect storm of hills and tailgating, that’s what. In this case, driver Yannick Dalmas, racing for Team Porsche in the 1998 Petit LeMans at Road Atlanta, was drafting the car in front of him while zooming over a rise. As he crested the hill, the car’s suspension pulled up, allowing more air to flow under the car and creating lift. Simultaneously, the draft from the car in front of him interrupted the airflow over the nose of Yannick’s car, sapping the much-needed downforce that kept the car in contact with the pavement. Without that downforce, there was nothing to stop the car’s nose from continuing upward once it started. After that, it’s pure physics opera: The nose of the car leaves the draft zone and enters the airstream, which accelerates the lift and pushes the nose backward while the weight of the rear-mounted engine continues its forward momentum. Voilà! A fantastic, white-knuckled twirl that—luckily—sustained enough momentum to end upright. Must have been an awesome ride. (Dalmas walked away uninjured.) —Martha Harbison
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