Crossing the line

That victory in the Belgian Grand Prix would be followed by a one-two finish in Spain for the American and his new Swedish team-mate. During practice at the Jarama circuit, the cars of Andretti and Peterson were consistently a second a lap quicker than the best of the demoralised opposition. And yet only two years earlier the famous English team, whose cars had carried Jim Clark, Graham Hill and Jochen Rindt to the world title, had been on its knees, with some commentators predicting an imminent demise.

It was in a state of mutual desperation that Colin Chapman, Lotus’s founder and presiding genius, and Andretti met for breakfast at their hotel during the Long Beach Grand Prix in 1976. Lotus’s last win had come two years earlier, while Andretti, America’s leading driver, had just learned that the Parnelli team, with which he had spent two frustrating years, would be pulling out of F1 after only three rounds of the new season.

The two men knew each other well. The 47-year-old Chapman, who had trained as a civil engineer before starting his career in motor racing with a home-made special built around a pre-war Austin 7. The Italian-born Andretti, 36, had emigrated to the US with his family in childhood; he had won America’s premier single-seater championship by the time Chapman gave him his first experience of F1 with a handful of races in 1968 and 1969. Now, both at a low ebb, they made plans for a reunion. At the next race, a month later, Andretti would be in one of Chapman’s cars. The Lotus 77 was a stop-gap design, but the presence of the forceful American helped inspire development work that led to his first victory for the team in that year’s final round, under the slopes of Mount Fuji.

A new car, the Lotus 78, was ready for the following season, boasting a significant innovation. Its design made pioneering use of a shaped underbody to generate downforce, borrowing from a principle Chapman had spotted when studying the wing-mounted radiators of the wartime De Havilland Mosquito, where the expelled air had been used to provide lift. Chapman realised that if the design were inverted, it could be used to pull the car downwards, increasing the grip of the tyres and therefore the speed at which corners could be taken.

Chapman’s technical team – including the former BRM men Tony Rudd and Peter Wright, chief designer Ralph Bellamy and vehicle engineer Martin Ogilvie – had spent time at Imperial College in London, where for the first time the design of an F1 car was refined by putting it on a rolling road inside a wind tunnel. By the time they returned to Long Beach, 12 months after their breakfast negotiation, it was effective enough to give Andretti the first of the four wins that took him to third place in the 1977 drivers’ standings.

After further investigation into what had become known as ‘ground effect’, the team produced a car for 1978 that would relegate its rivals to the status of museum exhibits. To the uninitiated, the smooth lines of the new Lotus 79 looked simply like the latest, most aesthetically ravishing development of conventional aerodynamic theory, which concentrated on providing the least possible hindrance to the air flowing over and around the bodywork at speed. But the 79’s precious secrets were hidden beneath its shapely bodywork, in the rectangular tunnel formed by the space each side, between its wheels.

Designing the whole car around this theory required removing obstructions from that underbody space in order to increase the volume and speed of the air flowing through it, creating a low-pressure zone that induced downforce. Where the previous design had split the fuel load between twin tanks located in the sidepods, now the cockpit was moved forward to make space for a single 30-gallon fuel tank between the driver’s back and the mid-mounted Ford Cosworth DFV engine, whose exhaust pipes, formerly positioned under the car’s tail, were rerouted to emerge through the upper rear bodywork. And now there were pendent skirts running along the bottom edges of the sidepods, staying in contact with the ground and eliminating spillage, channelling the airflow out between the rear wheels.