Jenks on aerofoils
It was inevitable that Matra should be first to have a movable aerofoil on their grand prix car, in view of their association with flight-control mechanisms. There is a misconception that Jim Hall’s Chaparral was the first car to use a movable aerofoil, whereas a similar device appeared on a Porsche Spyder RS designed by Swiss engineers, the cousins May, in 1956. The trouble was that no scrutineer appreciated the theory, some being convinced it was an air brake. The setbacks at the two sportscar races they entered caused the Mays to lose heart.
A friend met Michael May at the Targa Florio last year and talked about aerofoils, May being interested in the recent developments. Viewing the grand prix scene today, the Mays could be justified in feeling bitter towards the race organisers at the Nürburgring and Monza. The Matra’s aerofoil was controlled by a lever system from a motor that was energised by a contact on the brake pedal. When the brakes were applied, the aerofoil was tumed into a steeper angle. This presented a greater frontal area and some free braking and the downward thrust was increased, helping to keep the rear wheels on the ground. Matra has been testing a control mechanism operated by the gear lever, so that as the driver changes down the angle is altered; it returns to the original position as he changes up. —