A look back at the groundbreaking, ground-effect Lotus 78
This revolutionary Lotus was the first competitive ground-effect F1 car
Lotus had dominated great swathes of the 1960s and early ’70s with some impressive machinery: the Type 25, the 33, the beautiful 49 and finally the 72. But by 1976 the performance of their 77 was causing Lotus founder Colin Chapman concern. A new car was required and Chapman was adamant that the Lotus 78 would be a completely different machine. Chapman had studied the radiators on the wings of a Mosquito fighter plane and found that the hot-air outlets produced lift. He deduced that if this was inverted on an F1 car, it would boost downforce. He handed the project over to head of engineering Tony Rudd, who put together a team that included chief designer Ralph Bellamy, vehicle engineer Martin Ogilvie and aerodynamicist Peter Wright.
An inverted wing profile wasn’t a completely new idea in F1; Rudd had tested the concept at BRM. But the eureka moment came when Wright was trying various car body shapes in a windtunnel. He noticed that as the speed of the rolling road increased, the car (and specifically its sculpted underside) was drawn closer to the road. When he added cardboard sides, downforce levels soared – and so ‘skirts’ were born.
Chapman gave the project the green light and after further design and engineering work, plus more time in Imperial College’s windtunnel, the 78 was put into production – taking design cues from the ageing 72. With a similar wedge shape and internal layout, the 78 had a stronger, narrower monocoque. The bodywork was made from fibreglass panels, with aluminium used to strengthen the chassis.
A longer wheelbase, better weight distribution and detailed aerodynamics helped, but it was all about the car’s underbody. In addition, the positioning of the radiators meant the hot air they expelled passed over the upper bodywork, creating ever more downforce. This boosted grip, which increased corner speeds. Initially brushes were attached to the sidepods to keep the low-pressure area beneath the car, but these were later replaced with movable rubber skirts.
Five examples were built, known as the John Player Special MKIIIS. The car was ready to race by mid-1976, and the team immediately knew they’d come up with something special. Lead driver Mario Andretti spent a lot of time with the car at the team’s Hethel test track, describing the experience of driving the 78 as if it were “painted to the road”.
Andretti pushed Chapman to run the car in 1976, but Chapman wanted to keep his powder dry since the title was already out of reach and he was wary of alerting the rest of the grid to what he had up his sleeve. The 78 therefore made its debut in the first race of 1977, the Argentine GP. Andretti qualified eighth and Gunnar Nilsson P10, but only one car started the race after a fire extinguisher exploded in Andretti’s car during Sunday warm-up. Andretti took over his teammate’s 78 for the race but retired with two laps to go when a rear wheel bearing failed, although he was still classified P5.
Further retirements for Andretti in Brazil and South Africa, with Nilsson managing P5 in the former, were the precursor to the car’s first win at Long Beach. Andretti had qualified second but his win was a little fortuitous since he had followed Jody Scheckter’s Wolf for most of the race, until a slow puncture got the better of Scheckter letting Andretti through with two laps to go. That popular home win was followed by another triumph, this time from pole, in Spain.
Despite these two wins the 78 suffered various teething problems. The low-pressure area under the car was too far forward, which meant a larger rear wing was needed, which, in turn, caused drag at high-speed circuits, although a small wing was later designed that enabled Andretti to claim victory later on in the season at Monza. Nilsson’s sole win came in the Belgian GP at a wet Zolder, and Andretti was victorious in France.
The brakes weren’t great and the trusty Ford Cosworth DFV was no match for the flat-12 engine in the back of Niki Lauda’s Ferrari, which, in turn, forced Ford to search for extra speed at the cost of reliability. This was what lost Andretti the title in 1977, even though he won more races than eventual champion Lauda. That said, Andretti still loved it: “If I was going to choose the car that gave me the most satisfaction winning races, then I would say the Lotus 78 rather than the 79.”
Other teams tried to copy it, but were hindered both by the skirts (which hid the underside of the car effectively) and the team’s secrecy. Lotus started the 1978 season with the same car and it was still competitive enough to enable Andretti and Ronnie Peterson to win two of the first three races. Peterson’s P2 in Belgium was the last podium for the 78 and a final scheduled appearance for the car with the works team. Héctor Rebaque privately campaigned the original 78 prototype throughout 1979 and, tragically, Lotus brought a 78 out of retirement for Peterson in Italy, the race that cost him his life, after his 79 was damaged in practice.
Andretti would win the title that year and while the new 79 took an extra five wins from the remaining 11 races, 18 of his 64 points came from the 78. It was in a class of its own.
“THE CAR THAT GAVE ME THE MOST SATISFACTION WINNING RACES WAS THE LOTUS 78” MARIO ANDRETTI
THE LOTUS 78
SPECIFICATION Chassis Aluminium monocoque Front suspension Double wishbones, inboard spring/damper Rear suspension Parallel top links, twin-radius arms, lower wishbones, outboard spring/damper Wheelbase 2,741mm Engine Ford-cosworth DFV V8 Engine capacity 2,933cc Output 475-495bhp Gearbox Hewland FG400 5-speed manual Tyres Goodyear Weight 588kg Notable drivers Mario Andretti, Gunnar Nilsson, Ronnie Peterson
RACE RECORD Starts 53 Retirements 23 Wins 7 Poles 9 Fastest laps 7 Other podiums 4 Points 106