Michelin first major technical partner for Project 56 DeltaWing Prototype; 50% of the weight, power, aerodynamic drag, and fuel and tire usage for Le Mans racer
|The DeltaWing. Click to enlarge.|
Michelin will be the first major technical partner to support the Project 56 DeltaWing prototype car in the 2012 running of the 24 Hours of Le Mans. Michelin has developed a tire solution that pushes the performance envelope and matches the innovative DeltaWing strategy to reduce by half the weight, power, aerodynamic drag, and fuel and tire usage of a Le Mans prototype race car, while delivering the same speed and performance.
The front tires on the ultra-narrow front track DeltaWing are only four inches wide; both front and rear tires will be fitted to 15-inch rims (compared to 18 inches on traditional LMP1 sports cars). The Michelin tire sizes for the DeltaWing project are: 10/58-15 (front) and 31/62-15 (rear).
Tires are a critical part of the DeltaWing design and Michelin relied heavily on its own history of winning endurance races while developing these tires. The four-wheeled DeltaWing features a virtual three-point layout with narrow front track, wide rear track and significantly reduced aerodynamic drag. With this unique chassis layout, the tire solution presented distinct challenges.
During the development process, Michelin engineers worked side-by-side with the DeltaWing team in order to understand the speed, load and stresses that the tires might experience.
The announcement of the DeltaWing project at Le Mans this year drew enormous interest around the world, and not just from race fans. The car is very different. People look at this car and say ‘How will it turn?’ and they recognize that there are some very interesting ideas at work. We look forward to being part of the answers.—Nick Shorrock, director of competition, Michelin
Michelin has significantly extended the wear rate of its tires and reduced the number of tires used by its technical partner teams at Le Mans by more than 20 percent in the past three years. Michelin also has extensive experience in running multiple stints—two, three, four or even five—on the same set of tires in endurance racing.
DeltaWing. The Project 56 consortium features Dayton’s Highcroft Racing running the test and race program, Ben Bowlby and DeltaWing Racing Cars designing the unique entry, Dan Gurney’s All-American Racers building the initial prototype and American Le Mans Series founder Don Panoz providing the unique lightweight R.E.A.M.S. bodywork material and acting as a key advisor.
As spec’d for the 24 Hours of Le Mans 2012, the car features a liquid-cooled 4-cylinder 1600cc intercooled turbocharged engine that will produce approximately 300 hp (224 kW) at 8,000 rpm and weigh 70kg. The transmission is a 5-speed plus reverse longitudinal design with an electrical sequential paddle shift actuation. The differential features an efficient variable torque steer/differential speed-controlled planetary final drive reduction layout; the entire transmission weighs only 33kg.
Vehicle weight distribution is necessarily more rearward than traditionally seen with 72.5% of the mass on the larger rear tires. 76% of the aerodynamic downforce acts on the rear of the car which has an lift to drag ratio of >5.0.
Rear wheel drive coupled with the rearward weight and aerodynamic distributions greatly enhances inline acceleration capability.
Unique amongst today’s racing cars, more than 50% of the vehicle’s braking force is generated behind the center of gravity giving a dynamically stable response. Locking propensity of the un-laden front wheel at corner entry is greatly reduced due to virtually no front lateral load transfer with the narrow track and wide rear track layout. Steered wheel “scrub drag” moment is virtually zero, greatly increasing tire utilization and reducing mid-turn understeer.
The “56th entry” at Le Mans is a special invitation extended by the Automobile Club de l’Ouest, the organizers of the annual 24 Hours of Le Mans race, to encourage innovation and the introduction of new technologies. The 56th entry may race outside the standard technical classifications. The 80th running of the 24 Hours of Le Mans will be June 16-17, 2012, at the 8.47-mile Circuit de la Sarthe, approximately 90 miles southwest of Paris.
The DeltaWing concept was unveiled today at Road Atlanta as the teams prepared for the final round of the 2011 American Le Mans Series presented by Tequila Patrón—the 10-hour/1,000-mile Petit Le Mans powered by Mazda.