No. 33 The Lotus 79
Not the first car to embrace ground effect – but the first to get it right
There’s an old engineering maxim that if something looks right, then it is right. The Lotus 79 must surely be one of the best-looking grand prix cars of all time; wide, low, perfectly proportioned, unfussily detailed – and, on track, utterly devastating.
The 79 wasn’t the first car to make use of ground effects to boost cornering grip – that accolade goes to Can-Am racer Jim Hall’s Chaparral 2J, which used a pair of fans to suck air from under the car (an idea later resurrected in F1 by Gordon Murray for the short-lived Brabham BT46B fan car). But it was the first to get it right.
Lotus founder Colin Chapman spent much of the 1970s looking for the next big technical step that would deliver a crushing on-track advantage. But time and again he expended his energies in the wrong direction – either on technical dead ends in F1 or by becoming distracted by his growing road-car operation. By 1976, his design team had failed to come up with a credible successor to the 72, a title-winning car in 1970 and 1972, but now long in the tooth.
Lead driver Mario Andretti pronounced their 1976 car, with its complex multi-adjustable suspension, “a dog”. This prompted Chapman to look to aeronautics: he grew fascinated by the idea of using an upturned aircraft wing profile to create the opposite of lift. Lotus engineers Tony Rudd and Peter Wright had experimented with the idea while working for BRM, but had to drop it due to a lack of resources. With Chapman’s backing they got time in a windtunnel at Imperial College to prove the concept of shaping the underbody to create downforce. Here serendipity played its part: the basic windtunnel model, made from balsa wood and cardboard, began to sag as the low-pressure area under the car took effect. The nearer the outer edges of the sidepods got to the ‘ground’, the greater the effect.
Thus the Lotus 78, which made its debut at the first race of 1977, featured full-length sidepods concealing inverted wing profiles within, plus sliding skirts on each side, which sealed the gap between the car and the track. It noticeably bucked the trend for short sidepods, but even so rival teams could not fathom the car’s advantage.
The 78 won five races in 1977 in the hands of Andretti and Gunnar Nilsson, and a further two in 1978 before it was replaced by the 79. The new car built on the strengths of the 78 and sought to eliminate its faults, chiefly poor reliability, stemming from a chassis that wasn’t strong enough (due to Chapman’s fixation with low weight), and an aerodynamic centre of pressure that was too far forward.
Finessing the venturi within the sidepods, and packaging them so the rear suspension didn’t interrupt internal airflow, yielded so much more downforce that the 79’s chassis had to be strengthened further, contributing to its delayed debut. Andretti and team-mate Ronnie Peterson scored four one-twos before Peterson’s fatal accident. Andretti won the drivers’ title, with Peterson a posthumous second.
The 79’s success led Chapman to prioritise downforce on the Lotus 80. The more aero-efficient Williams FW07 – based on the 79 – took the title in 1980, and Chapman never again saw such dominance.