Case Study – Corvette C6RS Active Wing
Pratt & Miller’s Corvette C6RS supercar delivers breathtaking performance with everyday drivability. Now the C6RS has surpassed its racing counterparts with the addition of an active rear wing. While movable aerodynamic devices are widely banned in racing, the C6RS takes full advantage of the benefits of a rear wing that deploys at high speeds to balance aerodynamic downforce and improve stability.

DESIGN:
The project’s objective was to balance the aerodynamic forces acting on the C6RS at speed. The car’s low stance and extended front spoiler create aerodynamic downforce on the front wheels; the rear wing complements the aero package by producing downforce on the rear wheels. This aero balance promotes driver confidence and improves vehicle stability during high-speed braking and cornering.

DEVELOP:
Pratt & Miller engineers used the company’s extensive computational fluid dynamics (CFD) capabilities to evaluate the aerodynamic performance of various wing designs digitally. Virtual testing allowed the engineers to analyze the wing’s profile, height, angle of attack, and placement relative to the rear deck.

CFD analysis predicted that the active wing would produce an additional 306 pounds of downforce at 200 mph in the deployed position, with an additional 63 pounds of drag. This downforce-to-drag ratio underscored the aerodynamic efficiency of the active wing design.

BUILD:
The Pratt & Miller design staff used a Faro ScanArm laser line probe to digitize the complex compound curves of the Corvette C6RS bodywork. These surface scans were subsequently used to refine the wing profile and the pocket that receives the retracted wing. Articulation studies were performed to check for clearance between the wing, body panels, and the linkage that raises and lowers the wing.

Pratt & Miller’s in-house composite and machine shops manufactured the wing and actuating mechanism. The wing mechanism is powered by a compressed air system used by the Corvette C6RS’s ArvinMeritor Dynamic Height Control (DHC) suspension. Wing activation is controlled by the DHC Mototron controller. By utilizing the existing DHC pneumatic power and ECU, minimal additional hardware was required to implement the active wing: a check valve, solenoid valve, air lines, pneumatic cylinder, and mounting brackets. In normal operation, the DHC controller deploys the wing at 75 mph and retracts it at 45 mph. An override switch allows the driver to lock the wing in the retracted position to minimize drag when performing top-speed runs, and a lockup feature keeps the wing in the raised position regardless of speed.

RACE:
The Corvette C6RS active wing was tested at the GM wind tunnel in Warren, Michigan, and test results correlated with Pratt & Miller CFD simulations. CFD and wind tunnel tests measured an additional 220 pounds of downforce with the wing deployed while improving front-to-rear aerodynamic balance. The benefits of the active aerodynamics allow for reduced drag during normal highway operation while adding increased high-speed stability when needed during cornering and braking maneuvers.

WIN:
Vehicle testing at Michelin’s Laurens Proving Ground and Oscoda-Wurtsmith Airport confirmed the vehicle characteristics that were predicted by the CFD analysis and measured in wind tunnel tests. With the wing deployed, drivers reported improved high-speed stability. This project is another example of Pratt & Miller applying advanced technology to enhance the driving experience for Corvette C6RS owners.