appeared in July 1976. Mario Andretti wanted to introduce the car early, possibly at the Dutch Grand Prix that year but was overruled by Chapman, as he didn't want other teams discovering what Lotus had achieved. The 78 was introduced at the first race of 1977, and proved to be the class car of the field that season, winning five races. The car proved relatively easy to set up and modify, with particular attention paid to the undercar aerodynamics and their interaction with the track surface, hence a stiffer suspension design which was required to maintain the aerodynamic effects. Development The 78 was loosely based on the Lotus 72, sharing the same basic wedge shape and internal layout, but featuring detailed aerodynamic improvements, better weight distribution and a longer wheelbase. It had a slimmer, stronger monocoque made from aluminium sheet and honeycomb, which was developed from the 77. The bodywork was made up of fibreglass body panels with aluminium used to strengthen the chassis at points. The car created quite a stir when it first appeared, and outwardly seemed ahead of its time. Internally of course, it was a quantum leap ahead. Andretti worked hard with the car, testing for many thousands of miles at the Lotus test track in Hethel. Based on Bernoulli's discoveries, the underside of the sidepods were shaped as inverted aerofoils, in the same vein as conventional wings but on a much larger scale. Wright and Chapman had discovered that by shaping the floor of the car in this way, they could accelerate the air passing through the gap between the ground and the underside, thereby reducing the air pressure under the car relative to that over it. This created significant underpressure, effectively sucking the vehicle down and forcing the tyres harder onto the track. Copying the Mosquito's radiator design, the radiators were positioned so that the hot air escaping would pass over the upper bodywork of the car, creating even more downforce. To make the suction effect as great as possible, the monocoque was slimmer, forcing the air passing through between the ground and the inverted wing shape cover as much as possible. The greater force downwards on the tyres gave more grip and thus higher cornering speeds. This ground effect had the great advantage of being a low drag solution unlike conventional wings, meaning that the increased cornering ability was not compromised by a