Chevrolet Impala SS

The Chevrolet Impala SS. This CFD analysis contrasts the effects of a conventional rear spoiler on a NASCAR Monte Carlo SS (top) and the rear wing used on the Impala SS race car (bottom). Blue in the wake of the car indicates turbulence. The flow of air between the deck lid and the wing produces significantly less turbulence behind the car than the spoiler. This less turbulent air allows a second car to run close behind without suffering as much aerodynamic instability. NASCAR teams can adjust the wing's angle of attack can from 0 to 16 degrees to suit track conditions.

AIR PRESSURE COMPARISON FRONT VIEW - Generated by Computational Fluid Dynamics (CFD), this illustration compares the aerodynamic characteristics of the NASCAR Impala SS (foreground) and the Monte Carlo SS (rear). The colors on the body surfaces represent relative pressure, from red (highest) to green (moderate) to blue (lowest). Similarly, the colors of the streamlines around the cars indicate the pressure in the surrounding air from red (high pressure) to blue (low pressure). High pressure on the nose and headlights of the Monte Carlo SS shows that this area generates the majority of the car's front downforce; this area is blue on the Impala SS, indicating low pressure and lift. Dark red on the horizontal surface of the Impala SS's front splitter shows that this aerodynamic device generates significant downforce. NASCAR allows the splitter to be adjusted from four to six inches ahead of the bumper recess to fine tune the aerodynamics

AIR PRESSURE COMPARISON SIDE VIEW - A conventional rear spoiler on a Monte Carlo SS race car (top) produces high pressure on the rear fenders, indicated by red. The plates mounted on the ends of the rear wing on the Impala SS race car (bottom) can be adjusted to produce low pressure on the left side of the vehicle, increasing side force and enhancing stability in high-speed corners, similar to the feathers on an arrow.