Last week I talked about the front splitter and its effect. The splitter is much more inconspicuous than what is on the plate for today: the rear wing. The rear wing does exactly what a wing on an airplane would do, just upside down. In 1738, a plucky young Dutch/Swiss mathematician published a book the explained the fundamental principle of speed to pressure ratios. Daniel Bernoulli observed that when water in pipes with a large diameter transitioned to pipes with a smaller diameter, the pressure would increase in the smaller pipe. Many years later, Bernoulli’s principle was applied to the airfoil; stating that when air flowed over a wing shape a pressure differential was created causing lift.

Although not the first to dabble in aerodynamics in racing, Chaparral Cars is widely considered the first to do it successfully.  Jim Hall would race through the 60′s and 70′s radical new cars that he designed using his engineering background and an impressive hand behind the wheel of  a race car. His cars featured movable wings and, in one of his last cars, fans to suck air out from underneath the car. Hall’s cars were extremely successful in the Can-Am series and lived on in legend to this day.

Today, rear wings are a huge part of the aerodynamic success of vehicles simply because they can create huge amounts of downforce. Put together with the downforce created by the front splitter, at speed the car can have thousands of pounds of artificial weight added to it. This balance is very important because just like adjusting the suspension to account for handling, the aerodynamic elements will play a large role in the overall stability at speed. Having too much front downforce will cause the car to be very loose and vice versa. Also there is the element of drag to consider. The rear wing will cause massive amounts of downforce but also cause lots of drag, slowing the car down and making higher speeds much harder to attain. This balance between top speed and handling must also be considered when setting the car.

Next week: the venerable diffuser.