Improving racecar aerodynamics

Aerodynamic development of the 2001 NASCAR Dodge Intrepid R/T was accelerated with a combination of analysis and testing.

More than 20 years have passed since the Dodge division of DaimlerChrysler Corp. (then Chrysler Corp.) last had engineering involvement in stock car racing. During that period, the company continued to innovate and develop technology for aerodynamic research and development. Production vehicles introduced throughout the 1980s and 1990s continued to show the increasing fruits of those labors. Success on and off the track was due in part to the systematic approach followed by aerodynamicists. When the time came to develop a successful race vehicle, this approach created a natural latticework around which the aerodynamics program could be structured.

With less than 500 days to design, understand, and build a competitive vehicle, the 2001 NASCAR Dodge Intrepid R/T development team used a closed-loop approach to testing. Scale wind-tunnel models and computational fluid dynamics (CFD) were used to identify program direction and to speed the development cycle vs. the traditional process of full-scale testing. In preparation for race competition, external simulations were performed to correlate experimental data, visualize flow around vehicles, and conduct complex drafting studies. Many of the techniques used during the development program were in standard use throughout the automotive industry; however, it was the unique simultaneous application of these processes that ensured the most competitive design feasible for the time allowed.