The Lotus 88 - Ingenuity quashed

One thing about Colin Chapman and his staff at Ketteringham Hall, the Research and Development centre of Team Lotus, is that they do have a go and do not sit around waiting to see what others are doing before they design a Formula One car. Since they got on to the subject of aerodynamics, with particular reference to the flow of air under the car, at a time when most designers were trying to prevent any air from going under their cars, they have discovered a lot of interesting things about car and air behaviour at high speed. If you are going to look at the passage of a racing car through the air like you do an aircraft, then there are many things which spoil accepted theories. One of these is the exposed and rotating wheels, but rules have forbidden total enclosure on Formula One cars since 1960, so wheel disturbances are something you have to live with in Formula One.

An aircraft in level flight does exactly that, it keeps level, so that the airflow all around it can be considered stable. A racing car does anything but remain level. Under acceleration it takes a nose-up attitude (or tail-down), on corners it rolls and under braking it nose-dives, with the front down and the tail up. All these movements might not be obvious to the casual observer, but experiments with instruments coupled to the various parts of the car show clearly how the space between the underside of the car and the ground varies. When this happens the aerodynamic centre-of-pressure moves and this is bad for aerodynamic stability. For a long time Chapman and his design staff have been worrying about this problem and have been looking for a solution whereby the aerodynamics of a Formula One car could be kept stable, while the mechanical components did what the ground undulations or the dynamics required of them. In other words they wanted to divorce the two parts of the car, the aerodynamic functions and the mechanical functions.

This was the solution they arrived at with the Lotus 88, long before there was any ban on sliding side-skirts. The bodywork and the side-pods were designed to form a single complete unit, consisting of two rigid side-plates running the whole length of the car, joined by three titanium cross-members; these side-plates carried the radiators, with the air exiting at the sides. Attached to the lower edges were the undersides of the side-pods and on the top the upper body surface and this whole structure was mounted on small coil spring/damper units to short links attached to the wheel uprights. Literally inside this structure sat a conventional cockpit monocoque carrying the driver and the fuel tank, the engine and gearbox and the main suspension units, with rocker-arms and wishbones running out to the wheel uprights, this monocoque being made of a new compound of Carbon Fibre and Kevlar. In the original design the side-plates ol the aerodynamic chassis, which Chapman mistakenly called the primary, or first chassis, carried the then legal sliding side-skirts which hung down and rubbed on the ground, thus sealing the channel of air under the car.

With the banning of sliding side-skirts the side-plates of the aerodynamic chassis were set to give the regulation 6 centimetres ground clearance when stationary. This is when the trouble started. It was pretty obvious that at speed the downforce created by the air-flow over and under the aerodynamic chassis was going to press the whole of the bodywork downwards compressing the four mounting springs sufficiently to make them become coil-bound, and thus become solid, then all the down-force was going to be transmitted directly, unsprung, to the wheel uprights, and thus to the tyres, which is the basic object of using down-force. Meanwhile, the mechanical chassis, carrying the driver, engine, gearbox etc., could remain static within the bodywork, until dynamic or road conditions caused the main suspension to work. Since 1970 all aerodynamic effects have had to transmit their down-force to the tyres through the entirely sprung parts of the car, which is to say that aerofoils and fins are not allowed to be attached directly to the wheel uprights. Entirely sprung parts of the car was interpreted as meaning the chassis, though in a Formula One car these days it is not easy to say what the chassis is, with the engine being a major structural part ot the whole car. Chapman said the Lotus 88 had two chassis, the aerodynamic one, which he called the first chassis and the mechanical one which he called the second chassis, but the opposition would not accept that and insisted that it was illegal to transmit the aerodynamic down-force directly to the wheel uprights. There was a lot of confusion over the interpretation of the rules when it came to defining the word chassis, for no-one was quite sure whether the word was meant to be singular or plural, it being the same word in both cases. Most people thought it meant singular, but there was no valid reason to suppose this.

Then the Lotus 88 was attacked on Article 274/3 “Coachwork and Dimensions”, Rule 7 which specifies that any part of the car influencing its aerodynamic performance must be rigidly secured to the entire sprung part of the car and must remain immobile in relation to the vehicle. No-one had defined what the entirely sprung part of the car was, nor had they defined what the vehicle was in the second part. Confusion reigned at Long Beach, again in Brazil and also in Argentina and a lot of people were protesting, some on the principles involved, some on word details, some against the mis-managernent by officials and scrutineers, some on Rule 7 Art. 3, others on aerodynamics acting directly on the wheel uprights. It is important to realise that none of this was involved with dodging the skirt-ban ruling, even though many journalists did not seem to realise this. Meanwhile Gordon Murray of Brabham was deliberately dodging the skirt-ban rule with his hydro-pneumatic suspension, but there was so much flak over the Lotus 88 that many people missed this fact.

A tribunal was held to make an official ruling on the Lotus 88, comprising a group of FIA members not involved with Formula One, and they decided that it was breaking the rules and was illegal. They applied the general rules under Definitions, Article 252, where it says Mechanical components include all parts for the propulsion, suspension, steering and braking and all accessories whether moving or not which are necessary for their normal functioning. It then goes on to say Chassis: Structure of the car which holds mechanical components and coachwork together, coachwork having been defined as, All entirely sprung parts of the car linked by the external air stream, except the safety roll-over structures and the parts definitely associated with the mechanical functioning of the engine, transmission and running gear. It does not say that you cannot have the coachwork on one chassis and the mechanical components on another chassis. The “beefing” by other designers is principally against the aerodynamic down-force being transmitted directly to the wheel uprights, when the small springs become coil-bound (i.e. solid), and not through the car’s main suspension system.

For the moment the Lotus 88 twin-chassis, twin-suspension, first and second chassis car, call it what you will, has been deemed illegal and consequently banned. But we have not heard the last from the men at Ketteringham Hall. Meanwhile everyone is happily cheating on the footnote to Article 274/3 which says, Under no circumstances shall any suspended part of the car be less than 6 cms. from the ground, with the car in its normal racing trim, the driver on board. . . If corrections of suspension height can be made with the car in motion, the conditions defined above must be respected with the adjustment at the lowest static position usable in racing.

At Imola the official observers on the fast parts of the circuit said that “everyone, but everyone, had the sides of the coachwork touching the ground”. If everyone cheats then it is all right. I really do not see what all the fuss was about over the Lotus 88. The really pathetic part of the whole affair was to hear Chapman’s “friends” in FOCA say “if it’s accepted, we’ll have to copy it”. Had they said “if it’s accepted we’ll have to find a way of beating it” I would have gone along with them.

As it is the Formula One Constructors’ Association (FOCA) has split itself apart and can be considered dead and buried, apart from running a useful Travel Agency, providing they like your face and you have cash in your hand. — D.S. J.