“If it looks fast, chances are it is fast.”
In the case of the Lotus 79, truer words were never spoken. Among the most graceful race cars ever built, the Lotus 79 also ranks among the most successful, carrying Mario Andretti and Ronnie Peterson to six wins en route to both the 1978 Constructors Championship (for Lotus) and the World Drivers Championship (for Andretti). Beyond its race wins and championship, however, the Lotus 79′s ground effect design distinguishes it as one of history’s most influential race cars.
The Lotus 79 was the logical successor to the Lotus 78, a revolutionary race car in its own right. Although aerodynamics had played an increasing role in race car design since the advent of wings in the late ’60s, the Lotus 78 was the first to apply the Bernoulli Principle (which states that an increase in the speed of a fluid . in this case, air — occurs simultaneously with a decrease in pressure) to the entire chassis. Just as lift is created by accelerating the speed of air flowing over an airplane’s wings, so Chapman & Co. generated downforce by accelerating the speed of air flowing under their race car’s venturi-shaped sidepods . . . and employing sliding, spring-loaded skirts to seal that airflow under the sidepods. The resulting downforce effectively pinned the Lotus 78 to the ground (hence the term “ground effect”), while generating a fraction of the drag created by the large wings that had become ubiquitous on F1 cars. Although the Lotus 78 still employed wings, they were used to fine-tune the car’s balance rather than as the primary source of downforce.
The Lotus 78 was a highly effective race car, winning five times in the hands of Andretti and Gunnar Nilsson in 1977. However, the location of the 78′s rear suspension disturbed the airflow exiting the sidepods, while the design of the sidepods themselves was imperfect, creating a center of pressure so far forward that a large rear wing was necessary to balance the downforce. The Lotus 79 addressed these shortcomings. Thanks to what would now be deemed crude wind tunnel work, the sidepods were redesigned to create a more even application of downforce. They were also extended back to a rear suspension which had been reworked to provide a clean exit for the air flowing through the sidepods. This, in turn, enabled the Lotus 79 to utilize a smaller rear wing than its predecessor.
The platform for all this aerodynamic alchemy was a monocoque chassis constructed of sheet aluminum (rather than the 78′s honeycomb aluminum) in the interests of minimizing weight and keeping the cockpit narrow, thus enabling the sidepods to be as broad as possible in order to generate maximum downforce. Originally designed for a compact Lotus-Getrag gearbox, the 79 eventually utilized a five speed Hewland FG400 mated to the celebrated Ford-Cosworth DFV engine.
The result was as fast as it was beautiful. After an abortive debut in a non-championship race at Silverstone, Andretti practiced the 79 at Monaco but opted to drive his trusty 78 in the race. By the Belgian Grand Prix in June, the Lotus 79 was ready to race and it proved unbeatable, at least in terms of speed. Andretti and Peterson won six of eight races in mid-season, scoring one-twos at Zolder, Jarama, Paul Ricard and Zandvoort. The Lotus failed to win only the Swedish Grand Prix (where Andretti experienced engine trouble and Peterson was delayed by a punctured tire) and the British GP (where the American suffered a blown engine and the Swede’s fuel pump failed).
Andretti won the World Championship handily, clinching the title at the Italian Grand Prix with the U.S. and Canadian Grands Prix still to be run. Sadly, of course, Peterson lost his life due to complications from injuries he suffered in a start-line crash at Monza, having been forced to switch to a spare Lotus 78 after crashing his 79 in practice owing to a brake failure.