Downforce
The aerodynamic force that pushes the car toward the ground, increasing tire grip without adding weight. Wings, splitters, and diffusers generate downforce, allowing higher cornering speeds.
Deep dive
Road Vehicle Aerodynamics (Scibor-Rylski) quantifies the progression: a car with basic negative-lift wings achieves "sideways acceleration of 1.94 g with aerodynamic download of nearly 590 lb — about 36% of vehicle weight." With full ground effect, "sideways acceleration would be 2.88 g and the aerodynamic download would be 1760 lb, or about 106% of the vehicle weight" — the aero force exceeds the car's own weight. McBeath's Competition Car Aerodynamics explains ground effect specifically: at approximately "0.136c ground clearance" (about 2.5 inches), a wing can "produce up to double the downforce it would in freestream air." For HPDE, even small aero additions create forces that grow with the square of speed.
Sources
- Competition Car Aerodynamics 3rd Edition Mc Beath Simon
- Competition Car Aerodynamics 3rd Edition (McBeath, Simon)(p. 14, 29, 60, 476)
- Ultimate Speed Secrets - Ross Bentley(p. 42, 99, 156)