The Lotus 78 'wing car' designed by Peter Wright, Colin Chapman, Martin Ogilvie and Tony Rudd, was the car that started the ground effect revolution in Formula 1. In early 1976, Peter Wright of Lotus was experimenting with F1 car body shapes using a wind tunnel and a rolling road, when he began to get remarkable results in one of the models. Closer inspection found that as the rolling road's speed increased, the shaped underbody was being drawn closer to the surface of the road. Wright experimented with pieces of cardboard attached to the side of the model car body, and the level of perceived downforce produced was phenomenal. The results were presented to Colin Chapman, who gave Wright, aerodynamicist Martin Ogilvie and designer Tony Rudd free reign to come up with an F1 chassis design. The result was the Lotus 78 which appeared in July of 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. It was also used several times in the 1978 season.

Its sidepods, bulky constructions between front and rear wheels containing the radiators, were shaped as inverted aerofoils and sealed with flexible "skirts" to the ground. Wright and Chapman had discovered that by carefully shaping the underside of the sidepods they could accelerate the air passing under the car, thereby reducing the air pressure under the car relative to that over it and pushing the tyres down harder onto the track. The greater force downwards on the tyres gave more grip and thus higher cornering speeds. 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 decrease in straight line speed. The sliding "skirts" sealed the gap between the sides of the cars and the ground and prevented excessive air being sucked into the low pressure area under the car and dissipating the ground effect. Andretti described driving the 78 as if it was 'painted to the road.'

Unfortunately, the low pressure area under the car was too far forward, requiring a very large rear wing resulting in a lot of drag at high speeds. To compensate, Ford provided development versions of the DFV, increasing the car's speed but also sacrificing reliability. Andretti had no less than 5 engine faliures in 1977, costing him the world championship to Niki Lauda, even though he had won 4 races to Lauda's 3. But it was obvious that the 78 was something special, and other teams started scrambling to design their own version for 1978. The problem they had was that they didn't know exactly what was so special about the car, as Chapman and other members of Lotus came up with any number of excuses to hide the real reason. That as well as the skirts, which hid any view of the underside of the car.

The 78 was good enough to still be a winner in early 1978 before it was replaced by the Lotus 79, which was as far ahead of the 78 as the 78 had admittedly been ahead of the rest of the field in 1977.

Drivers: Mario Andretti, Gunnar Nilsson, Ronnie Peterson

External links

• Lotus 78 - season results; race photograph
• 78 - race and pit photographs
• 1/20 scale model and pit photograph of actual car
• Aerodynamic Illustration - Explanation of Side Pod Aerodynamics

Lotus vehicles | Formula One cars