Aerodynamic effect is mainly used to improve mechanic grip between tyre and asphalt with favourable effects for acceleration and the miles covered speed when cornering. In the second half of the 60's the concept spreading among Formula One designers, changed the terms of the aerodynamic research works carried out till that time: firstly they researched penetration above all, often grappling with aerodynamic lift phenomenon that lifted the single-seater at high speed. Then, they passed to the opposite concept, searching a drag able to force the single-seater downward and it's for that reason that still today Formula One has a coefficient of aerodynamic penetration comparable with the van one. First step was the use of upturned wing profiles on single-seaters. Colin Chapman, keen on aeroplanes, was among the pioneers who experimented these devices. He was the first who understood that the car body could also generate aerodynamic load and the Lotus 72 was the result of it with an advantage over the competition that has lasted for three years. At mid1970's everybody had by then learned the lesson, but Chapman was already conceiving a new idea that had to re-establish the Lotus superiority; his idea was to generate an aerodynamic load also under the car and not only obtained by the bodywork and wings. As a matter of fact it wasn't a novelty at all, given that there was a famous precedent: in the second half of the 1930's there was a fight between Auto Union and Mercedes to beat the absolute speed record. Cut and thrust between the ranks were frenetically following each other: big resources and new technologies as wind tunnels were allocated to study these streamlined monsters. To make an attempt to defend its record against Mercedes, Auto Union designed the 6.5.L, where numbers indicated the powerful capacity of the engine. The car body featured by "coke bottle" sidepods which went from mudguard to mudguard and from straps (flexible skirts) that sealed the car bottom as much as possible to the asphalt: the structure generated a kind of suck that stuck the car on the ground. The project paternity isn't clear: officially the car was designed by Eberan Eberhorst, but some existing memoirs seemed to involve Ferdinand Porsche, who had worked at Auto Union till 1937. The new record attempt was fixed on the 28th January 1938 on the Frankfurt-Darmstadt freeway and it ended tragically with Bernd Rosemeyer's death. The German crack racing driver, after running 429 km/h on the outward, had his car disintegrated on the return, betrayed by a lateral wind that made his car lose dangerously adhesion to the track. In so far as we don't know whether Colin Chapman was acquainted with that precedent, but in any case the idea he was developing still meant a novelty. To verify his intuition, in 1975 a research team was made under Tony Rudd's guidance: Peter Wright, Ralph Bellamy and Charlie Prior joined in it. They set about experimenting using the London Imperial College wind tunnel, very innovative one for the use of a rolling road. Inside the structure they promoted an in-depth study on wing profiles of different shapes, obtaining rather remarcable results. Tony Rudd, in Colin Chapman's biography written by Gerard Crombac, reported the results of those first experiments as follows: "the closer the wing profiles were drawn to the rolling road, the more negative pressure had terribly increased. When we realized that fact for the first time, the rolling road appeared to be lifting to catch up the profile! In fact, we were obliged to have the tunnel fitted so that the rolling road was held steady, and that's why we really understood the ground effect importance". Practically, the incoming air passed through a narrow slot under the inverted wing profile and went out accelerated due the increased gap between the profile and the rolling road, thus creating a lower pressure which attracted the two surfaces. On the basis of these results a project was elaborated for a single-seater (monoposto) equipped with big inverted wing profiles on the chassis sides, very close to the ground. It was also understood that the bigger was the profile, the major was the need to seal the ends to the surface, in order to avoid the introduced air going out laterally. The solution was to adopt side straps (or skirts) which excluded the air from flowing underside the monoposto. As for the radiators repositioning, Tony Rudd was inspired by De Havilland Mosquito, the Second World War aeroplane, which had sidepods embedded into the wing surfaces. Thus he discovered that by heating the air he created a dynamic effect. Lotus 78 was the result of those experiments: the car was received by the press and F1 engineers with scepticism. They didn't understand the role of those big sidepods, and in fact it took a lot of time before they could share the secret. The 78 missed the title in its debut season, mainly for Cosworth engine unreliability and bad luck, but in 1978, together with its evolution, the 79 dominated by gaining both constructors' and drivers' title with Mario Andretti. At the end of that winning season Colin Chapman realized that competition was once again catching him up, maybe faster than he expected. Instead of going on with the 79's evolution, he started a complete new project that made radical changes in the concepts till then developed: the Lotus 80.
To ground effect's limits
The new car creation took rather a long time, not only due to the difficulties encountered, but also because Colin Chapman wanted to have some chassis and spare parts enough to avoid the lot of troubles given the year before by the type 79, often available for Andretti only. To the team's problems in handling two different cars, a feeling of guilt was added for what happened in the Italian Grand Prix, where Ronnie Peterson lost his life after a terrible massive start line accident. Chapman's own conviction was that if the talented Swedish driver had the stouter 79 at his disposal instead of the old 78, he would have escaped death. Therefore the car presentation took only place in April 1979 on Brands Hatch circuit. When the veil covering the new car created by Colin Chapman was lifted, there was the enthusiasm of present journalists excited by Mario Andretti's optimistic statement: "The Lotus 80 will make the 79 look like an old London bus". Colin himself, with his usual charm, defined the 80 as "the most wonderful car I ever built". And in fact from the aesthetic point of view it was really striking. The main feature of the new single-seater was the complete absence of wings. The elimination was made possible after an accurate development of the car underside. The sidepods hiding the inverted wing profiles had the same early trend of the old 79's, but instead of ending in front of the rear wheels, they went further on the axis for the full length of the car. Same as the skirts. That fact had involved a hard work on the rear suspensions and axle shafts, which hadn't affect the air flow inside the side channels. The axle shafts and wishbones, actuating the spring units of the inboard shock absorber, were embedded into the bodywork and over the channels, while the only in sight parts were the lower triangles. To obtain an effective extractor aerofoil they had to design a slimmer new gearbox that was closed in a kind of keel. That new way to design the monoposto was the symptom of an epoch-making change: aerodynamics had no longer to bow to mechanics requirements, but the former was in a position to condition the latter, and that was the up-to-date Formula One basic concept. The lack of a real large rear wing was compensated by a bent shaped profile which formed the body ending part and was used to make slight adjustments to the basic aerodynamic load generated by the floor pan.. The front wings elimination caused the use of skirts running the full length of the nose and ending underside the cockpit. Like for the rear, a slight possible adjustment of aerodynamic load was allowed by a small profile, embedded on the upper area of the same nose. The need to generate downward force from the front side of the car had obliged engineers to go to the limits of regulations by the front projecting part. In fact, that one was 200 mm more than the old 79. Oddly, down-force generated by the new underside wasn't bigger than the 79's. The advantage they wanted to obtain was derived by the lack of wings and their consequent turbulences. Now an effective lower air flow corresponded also to a clearer upper flow: Colin Chapman valued the obtained advantage equivalent to around fifty horsepower more from the engine. That comparison explained what the English designer's were and other constructors' problems that used Cosworth engines: to intervene in chassis, aerodynamics and suspensions to compensate the lack of horsepower in respect of twelve cylinder Ferrari or Alfa Romeo. Though the monoposto was rather bulky, basic sizes of chassis were the same as the 79's: wheel base was 2750 mm, while the front and rear tracks were 1700 mm and 1630 respectively. From the 79 were also derived the worm and roller steering and the suspension layout featured by a wishbone in titanium and lower triangles on both axes. Brakes were mounted inboard on the rear and outboard on the front, with self-ventilating steel disks. However, they provided the use of both rear brakes outboard and new disks in carbon fibre. To construct the chassis they made great use of honeycomb, obtaining a stiffer and safer structure in case of accident, while the bodywork was made up of fibreglass strengthened by composite material. The unit construction body covered the whole mechanical parts, disclosing only the inlet trumpets of the Cosworth eight-cylinder. Radiators were fitted by the side of the cockpit, embedded into the sidepods: on the right the oil pod and on the left the water one. Large outlets on the bodywork allowed warm air to flow, but the problem that was mainly worrying Lotus engineers wasn't so much related to the insufficient cooling of fluids as to the overheating of the gearbox and rear brakes because of their embedding into a closed structure. Therefore they opened cooling ducts corresponding to the rear wheels. The cockpit, in spite of the chassis keeping the same size as the 79's, was larger and more comfortable one: Carlos Reutemann had the problem at heart as he felt rather uncomfortable in the old car. The Argentine driver had been recruited by Lotus in virtue of a big sponsorship from Good Year: the American tyre constructor had some trouble developing tyres with radial shoe, introduced by Michelin in 1977 and with them Reutemann had run in his precedent season with Ferrari. That year Lotus also saw the change in the car livery: John Player Special retired and Colin Chapman managed to make an agreement with Martini Racing. At those days, the Italian liquors industry policy was to favour the use of national colours on which to put its own red and light blue stripes. It was the first time since 1968 that the British Racing Green has been returning on the Lotus monoposto. The agreement with Martini turned out nothing exceptional and expired at the end of the year, leaving both parties dissatisfied. Luckier was the relationship with the other new sponsor, Essex, an American oil company came up from nothing. Its owner, David Thieme made a fortune taking advantage of the 1970's oil crisis and for Lotus he was a very munificent sponsor, at least till his financial crash in 1981.
LOTUS 80: a lemon car?
The Americans use the word "lemon" to designate the cars that are unsuccessful. The Lotus 80 was even a lemon farm: Carlos Reutemann's name, nicknamed Tarzan by Ferrari technicians, after some practice sessions at the wheel of the new monoposto, was changed into Cheetah. He returned to the old Lotus 79 and he didn't want to get off that car any longer, splitting the team in two factions. It wasn't the first time that Colin Chapman's drivers went on strike against one of his creations, because already in 1969 Graham Hill and Jocken Rindt had refused to drive the 63, an experimental single-seater with four-wheel drive. Out of spite, the English engineer called Mario Andretti, and made him run in the Lotus 63 at Nurburgring, where the American driver went off the track badly. Also as for the Lotus 80, Andretti, who respected Colin Chapman's technical qualities and knew how to work together with his team, sacrificed himself and managed to develop the monoposto. The main problem was the ground effect lack of stability as a condition: corners, irregularity on the asphalt and kerbs generated difference in the car height, through suspension oscillations. In those cases skirts didn't adhere more completely to the ground and some flow losses destabilized the downforce values. If then, unfortunately, the car should have been affected by a significant difference in the height, the aerodynamic structure of the bottom side could have suddenly become a carrying structure, making the car without control. The ground effect was a wonderful concept in a wind tunnel, where conditions were optimized, but not in the circuit reality. The lotus 80 based almost his full load on ground effect, and drivers found themselves with sudden changes of the aerodynamic setup which made the monoposto ungovernable and dangerous. First step was to refuse the idea of eliminating wings or aerofoil. Above all the elimination of the rear one turned out to be a risk: from first experiments in the wind tunnel, they realized that ground effect was maximum in the mid-car, losing force the more the airflow accelerated towards the diffuser exit. In the years to come, above all on fast tracks like Monza, we will see cars without front wings, but never without the rear ones. Lotus engineers designed a profile to put on the earlier one envisaged, whose side bulkheads were directly attached to the chassis, hiding the rear wheels. But on the Lotus 80 not even the aerodynamic front structure worked properly: after many tests with the skirts under the nose, they had to eliminate them and fit two conventional profiles on both sides. Under that dressing the car was lined up at the Spanish Grand Prix for Andretti only: Mario qualified fourth in the Lotus 80, at 5/10 from pole, and he gained a bright third place on race. Colin hoped he had solved his creature's problem, but the Ital-American driver's successful performance remained an isolated episode. Monaco wasn't certainly the ideal ground for a 4.5 m car. In fact, Mario qualified 13th and retired on race because a suspension broke after only 21 laps. In France it wasn't better and after obtaining the 12th time in practice, Andretti was betrayed by brakes. In both races he ran the 17th fastest lap. After the French experience the car was no longer lined up on race, but private practice went on: to solve the Lotus 80's problems meant to solve the problems generated by ground effect. The wing addition had caused a supplementary load, but it wasn't sufficient to give stability to the car. The way was to work out suspensions and limit their amplitude: to make clear what it was happening it's sufficient to think that suspension springs were five times stiffener than the ones used earlier than the ground effect era. According to Stephen South, at that time the test driver at Lotus, the stiffener were suspensions, the more stabilized was the load generated by the car underside, but vibrations increased dramatically to the point that it was impossible to keep one's foot on pedal. Moreover, vibrations affected chassis, bodywork and suspensions causing dangerous failures. Components' strengthening was required, with the lost of advantages of the weight obtained by using light materials. From these troublesome tests and considerations that derived, Colin Chapman came to an important conviction: if we could have used even stiffer suspensions and, at the same time, isolated the driver and other fragile parts of the car, we would have obtained a more stable ground effect without affecting the carrying structures. After carrying out lengthy research, in 1980 we arrived at the Lotus 88, a monoposto in which aerodynamic problem had been separated from the mechanical one with two overlapped chassis. The base was a honeycomb and carbon structure in which mechanical parts and cockpit were located. Directly linked up with the wheels it was featured by suspensions again soft to absorb the track roughness and allow the driver a good driving feeling. Over that chassis there was a second chassis suspended, with indipendent shock absorbers that included the body and other accessories like radiators. The structure had to guarantee the proper position of the aerodynamic elements, avoiding the skirts loosing the contact from the ground. If the Lotus 80 was without any doubt a failure, the judgement on the 88 was suspended. When Chapman's car appeared a feud started between him and FIA. The Association, in fact, judged the double chassis as an infringement of the regulation that banned the use of aerodynamic movable elements. After a long fight, Chapman was obliged to drop his plan, but from the few tests carried out, it seemed that the problem of the aerodynamic instability hadn't be solved completely, and in any case it would have been necessary a huge development work to set up the double chassis. The Lotus 88 wasn't the only idea got from the experience he learnt with the 80. In fact, the English team owned a very advanced system to acquire data from a consulting aeronautics firm. Before the difficulties encountered, advisors suggested an active suspension that should maintain skirts sealed to the asphalt under any conditions. At first it came to nothing, but after the 88 flop the experimentations began and without realizing it they started the electronic Formula One era. In fact, experimentation went on also after skirts had been banned and in December 1982 the monoposto 92, fitted with the new system, was tested. However, it was necessary to wait till 1987 for a systematic use on race. Colin Chapman was the designer who left his mark more than others in Formula One, but in going continuously so far in the technical research was also grossly mistaken. The Lotus 80 was one of those cases: according to some sports commentators of those days he made the mistake to consider the 79 as the maximum development point of the ground effect. From now on it was only a matter of minimizing the bodywork turbulences and making the system more efficient. He wasn't the only one who took that road: always in 1979, Tony Southgate, the smart Arrows' aerodynamic designer, conceived the A2 that from some points of view was more extreme than Lotus 80. Southgate also wanted a car without wings by optimizing ground effect. He was also betrayed by the wind tunnel ideal conditions which intensified ground effect, but then they were unlikely to find again on track. Like Frank Williams and Patrick Head, he was in the right the man who just restricted himself to making a carbon copy of the 79 and improving the idea that was in it: the Williams FW 07, in fact, missed the title in 1979, but dominated on next season.
- Crombac G., Colin Chapman, the man and his cars, Haynes Publishing, Yeovil 2001
- Guzzardi G., Cento Anni di Automobilismo Sportivo; Edizioni White Star, Vercelli 2001
- Mannucci C.M., Ayrton, attached to Autosprint, 2004
- Piola G., Effetto suolo con le minigonne, in Autosprint, 2002
- Zana A., A roadmap for a tentative explanation of Bernard Rosemeyer 1938 accident, www.kolumbus.fi/leif.snellman/main.html.