How Jim Hall's understanding of downforce changed the racing world

Understanding the meaning or importance of the words “net downforce” might seem inconsequential to most of the people in the world–unless you’re involved in motorsport. But even as late as 1961, when men had been designing, building and racing automobiles for almost 100 years, the word “downforce” hadn’t even been invented. 

It took a visionary, track-sensitive Caltech grad from Midland, Texas, to realize that aerodynamic lift, which might have seemed like a negative force affecting his car’s performance, might somehow be converted to an advantage. 

Newton’s third law states that for any action there is an equal and opposing reaction. Jim Hall’s first Chaparral, built by Troutman and Barnes in Southern California, had some serious nose lift at speed, but Hall, who was also a pilot, used his engineering background to counter the lift with self-designed spoilers. Instant improvement! That was just the beginning. 

Richie Ginther, then a development driver for Ferrari, also found a use for a “spoiler,” but in an entirely different manner. The Automobile Club de l’Ouest was seriously concerned about ever-increasing top speeds on its circuit, Le Mans. The horrific accident in 1955–when a Mercedes went into the crowd on the front straight, killing some 80-plus spectators–was an ever-present reminder that another such tragedy might well end the sport entirely. 

In an effort to reduce top speeds, the ACO mandated the use of full-height windscreens for 1962, thinking that increased frontal area would seriously decrease top speeds. When Ginther tested Ferrari’s first mid-engine sports racer, a model that would eventually become known as the 246 SP, on Modena’s local city circuit, he was instantly aware that the high windscreen had created a low-pressure area in the cockpit. This caused the V6’s exhaust gasses to be sucked up and back into the cockpit, making him slightly sick. 

Having been a helicopter mechanic in Korea, Ginther was also aero-savvy enough to request his mechanics rivet a simple 3-inch-high “fence” across the back end of his new racer. 

It solved the exhaust gas problem, but Ginther soon discovered that the hastily installed device had also reduced his lap time by almost 2 seconds. Downforce! Realizing that the car’s back end was now under increased pressure, making the front end feel “light,” Ginther had another similar compensating device installed on the front and went even faster!

Those two happenstance discoveries, and their brilliant driver-created solutions, changed high-speed motorsports forever. It was Jim Hall, however, who continued to use logic and the real science of aerodynamics to design and build cars that would eventually obsolete every competing marque in almost every aspect of racing, including the Indianapolis 500. Hall forced every top designer in the game to completely reconsider what they had created.

Jim Hall’s Can-Am creations, including the high-wing Chaparral 2E (above) as well as the 2J sucker car (top), transformed motorsports via their aerodynamic innovations.

Master motorsports journalist George Levy’s new book, “Texas Legend: Jim Hall and his Chaparrals,” took him seven years of working closely with Hall to extract some of the quiet Texan’s most interesting recollections of how he created several of the most important, game-changing designs in motorsports. 

And the pictures! The book includes images of cars never before seen and the reasons why we never saw them. Most racers are familiar with the fact that Hall somehow worked closely with GM to objectively test the Corvair, but they never knew until now exactly what was accomplished on Hall’s private test track in Midland, Texas. Hall finally disclosed to Levy answers to all those questions that most in racing have long wondered about. 

Here we get introduced to the passionate, creative teams that Hall assembled in the vast reaches of “nowhere” to experiment and fail and learn, resulting in the incredible racing machines that forever changed our sport. Levy’s book on Hall deserves space in every fan’s library, not just because of the history disclosed but also for Hall’s personal recollections of all who helped make it all possible.

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