Four-Wheel-Drive in Grand Prix

It takes a long time to progress

Attempts to put 4-wheel-drive into Grand Prix racing are by no means new, and date back to the Edwardian days, but successful attempts are another matter. Even so, Ferguson Research of Coventry showed us all in 1961 that a properly designed and well engineered racing car with 4-w-d was a serious proposition and could deal effectively with any two-wheel-drive racing car, in the wet or in the dry. Since the beginning of motor racing designers have explored the 4-w-d path, not always for the same reasons, nor in the same manner, but all were prompted by the basic feeling that it was illogical to drive a car through only two of its four wheels. Any study of the movements of the best four-footed animals will show them to be far superior in many ways to a two-footed animal, such as the homo-sapien, and certain far-thinking designers and engineers have always felt that a racing car, or private car for that matter, driven through all four wheels must be superior to one driven through only two, whether they be the rear ones or the front ones. Some attempts to produce a successful 4-w-d car were crude, others ingenious, but none were overwhelmingly convincing. In the very early days the Dutch firm of Spyker built a 4-w-d racing car, in the nineteen-thirties Maserati and Bugatti experimented, while in America the Gulf Oil Company sponsored Harry Miller’s 4-w-d project. Immediately after the war Cisitalia commissioned Porsche to design a 4-w-d car, which was very advanced and had great possibilities but was never completed in time for a race. When Daimler-Benz made their great onslaught in 1954 their Grand Prix Mercedes-Benz W196 was intended to have 4-w-d, but time defeated the project. Both Porsche and Daimler-Benz intended their 4-w-d layout to give the greatest advantage under acceleration, the dividing of the power and torque between the four wheels providing greater traction. Commercial vehicles, and in particular military ones, have used 4-w-d for greater traction since their early days, but the problems of cornering and suspension did not trouble them. Porsche intended the Cisitalia to do its cornering with rear-wheel-drive only and use the 4-wheeldrive for acceleration, the driver selecting the extra drive to the front wheels by means of a steering column lever. Daimler-Benz were thinking along the same lines, with the selection being made electrically and operated by a foot-switch; they had further ideas about making it automatic, controlled by slip on the rear tyres. In the lesser world of racing, particularly in sprints and hill-climbs, many amateurs experimented in the world of 4-w-d and one of the most successful and significant was a special called “Fuzzi”, designed and built by Robert Waddy. It was powered by two 500 c.c. Speedway J.A.P. engines, one driving the front wheels, the other the rear wheels, with a differential accelerator pedal that allowed the driver to control the engines independently. As an aside, it had a pure space-frame chassis and was built when the likes of Chapman, Broadley and Cooper were in their cradles, the name “Fuzzi” being derived from “fuselage” from the aeronautical world where Waddy got his inspiration. Anyone who watched “Fuzzi” accelerate in 1937/38 and record faster times in sprints with 1,000 c.c. against supercharged 1,500 c.c. arid 2,000 c.c. cars will have been convinced about 4-wheel-drive.

For many years the tractor king, Harry Ferguson, was convinced of the benefits of 4-wheel-drive, especially for road cars, both in the interests of efficiency and safety, but he had a hard time trying to convince the motor industry of the benefits of 4-wheeldrive. He formed Ferguson Research Ltd. for the express intention of furthering 4-wheel-drive and was convinced that he had the true answer to the steering, cornering and handling problems that 4-wheel-drive seemed to bring with it. Put very simply the Ferguson idea was that there should be a differential between the front wheels and one between the rear wheels, as most people had been doing, but in addition there should be a third differential placed between the pairs of wheels, and that this differential should be coupled with a device that would automatically divide the torque fore and aft as required. The effect of this system is that no single wheel can spin; either none will spin or all four will spin, which brings us back to our four-footed animal, whose four pads are controlled by the single brain, each corner reacting to local conditions. To be 100% convinced of the Ferguson Formula (FF) you have to see their single-seater research vehicle P99 accelerate across tarmac covered with irregular pools of water. I was fortunate enough to watch this apparent phenomenon at the Road Research Laboratory in 1961. When Harry Ferguson died he left sufficient money in trust for Ferguson Research to continue its work under the guidance and leadership of A. P. R. Rob and designer Claude Hill.

In 1961 the Ferguson P99 competed in the British Grand Prix at Aintree and Fairman drove it for all to see and evaluate its worth. Later that year Moss won the Oulton Park Gold Cup with it. The FF System was offered to British racing car constructors, but at the time B.R.M. were the only ones with any engineering facilities or sufficient money; the rest were small-time special builders with barely a milling machine or gear-cutting machine between them. B.R.M. made a half-hearted attempt with a 4-wheel-drive Grand Prix car and it was left to the Indianapolis world to exploit the Ferguson Formula, in the shape of STP-sponsored cars designed and built by Ferguson Research Ltd. In 1964 they built an Indianapolis car with a supercharged V8 Novi engine and in 1967 the STP turbine car. The Grand Prix world seem to be a timorous lot when it comes to experimenting and spending money on research, preferring to leave it to subsidiary interests. The money behind Indianapolis racing allows owners to be much more adventurous and 4-wheel-drive to the Ferguson Formula and other similar ideas have appeared steadily in U.S.A.C. racing.

At last 4-wheel-drive is appearing on the Grand Prix scene and both Lotus and Matra produced their first cars for practice at the Dutch Grand Prix. The Matra MS84 transmission was designed and built by Ferguson Research Ltd., while the Lotus 63, although designed by Lotus and manufactured in great part by ZF of Germany, follows in many principles that of the original Ferguson racing car of 1961. The Matra and the Lotus have approached the problem from entirely different directions, with the result that the only real similarities lay in the use of a Cosworth V8 engine and having all four wheels driven. Both firms used knowledge already gained, in the layout and construction of their cars, as would be expected, Matra’s fore-knowledge being limited to Grand Prix racing, while Lotus knowledge came from Indianapolis, having already built 4-wheel-drive cars for Indianapolis. The Matra MS84 from a distance looks very much like a normal Grand Prix MS80, the suspension layout and body shape being almost identical, whereas the Lotus bears no resemblance to a Type 49, but looks like the Indianapolis STP-Lotus cars, and, in fact, many parts are interchangeable.

Matra have taken their successful MS10 and MS80 design and, keeping the same basic conception, have designed 4-wheel-drive into it. As the first MS84 is very much a prototype and research vehicle it has a tubular space-frame, which is easier and quicker to build and modify than a stress-skin monocoque chassis. The suspension front and rear follows normal Grand Prix practice that has now become as standard as the half-elliptic spring and beam axle was in the vintage years. The Cosworth V8 engine is turned through 180 degrees so that the clutch and flywheel are just behind the driver and the 5-speed gearbox, central differential and control unit and the stepped take-off drive are all in one casing attached to the engine and under the reclining part of the driver’s seat. A standard G.P. Hewland gear-cluster is used as the basis for the gearbox, and from the FF unit enclosed drive shafts run fore and aft along the right-hand side of the cockpit almost at elbow height and a right-hand lever operates the gearbox. The fore-and-aft drive shafts run to offset differential housings with short transverse shafts fully enclosed and rigidly mounted on the chassis. The brake discs are mounted on the ends of these transverse rigid shafts, and because the discs are in close proximity to the suspension pivot points the only possible place for the brake calipers is low down, hanging under the discs. This obvious layout has brought about a vast reduction in unsprung weight and with the all-up weight being slightly more than the two-wheel-drive Matra, the all important sprung-to-unsprung weight ratio is greatly improved on the MS84 over the MS80. Very short universally-jointed drive shafts transmit the power from the ends of the rigid transverse shafts to the wheel hubs. Another advantage to accrue from the 4-wheel-drive layout, providing you are a disciple of old designers like Vittorio Jano, is the inevitable improvement in low polar-moment of inertia, and Jano would have been very pleased to see the Matra layout, as would have old Dr. Ferdinand Porsche. For those people who have become used to seeing a gearbox sticking out behind the rear axle centre-line the MS84 looks most unusual, for there are no mechanical parts sticking out of the back. Although the MS84 may look like the earlier MS80 from a distance it has three major technical advantages over its predecessor and they are, 4-wheel-drive, better sprung-to-unsprung weight ratio and a lower polar-moment of inertia, all of which are desirable in most designers’ handbooks.

Lotus have arrived at the same answers but from a different direction. Their thoughts go back to 1966 before the Ford Motor Company financed Cosworth Engineering to design and build the remarkably successful DFV engine. At the time they were using the H-16 B.R.M. engine, and like a lot of people, had thoughts of 450-500 b.h.p. in its second year of development. At the end of that year they began to make sketches and have thoughts about 4-w-d for Grand Prix racing, but the introduction of Ford money sent them off on a successful tangent with the Lotus 49 and the Cosworth V8. However, the 4-w-d thoughts were not abandoned, merely shelved, and a year later when their American contacts produced the Pratt and Witney turbine engine and STP money, they set off on a 4-wheel-drive course with the wedge-shaped Indianapolis cars. The two Grand Prix cars that appeared for practice at Zandvoort were direct descendants from the Indianapolis cars, many parts actually being interchangeable. There was no question of short-cuts or a research vehicle, the Lotus 4-w-d was designed as such from the start. The chassis is a stressed-skin monocoque rather like a bath, with the Cosworth V8 engine approximately in the centre, pointing rearwards, which is to say that the clutch and flywheel end of the engine are foremost. Between the driver’s seat and the engine is the 5-speed gearbox, transfer gears and torque control unit, but whereas Matra have the fore-and-aft drive shafts on the right, Lotus have them on the left. This is for two simple reasons, one that the car was derived from the Indianapolis cars, which were designed to have a left-side weight bias, and two, that by retaining the left-side layout there was no need to alter the starter motor position on the Cosworth engine. Matra had to convert the starter motor to a right-angle position, driving through bevel gears. The drive shafts run enclosed in tubes to the two cross-shafts, one at each end of the chassis, and these have differential units offset to the left. As must be obvious in any 4-wheel-drive layout the brake discs are best on the ends of the cross-shafts, reducing unsprung weight, and the brake calipers are hung below the discs. Short drive shafts run to all four wheels, and the hubs are sunk deep into recesses within the wheels. Lotus are great believers not only in a low polar-moment of inertia, but also in a 50/50 weight distribution and in the interests of the latter the driver is positioned fairly far forwards, so that the control pedals are ahead of the front axle cross-shaft and the driver sits with his legs under the cross-shaft housing. This layout left no room for any normal steering mechanism so the Lotus has all its steering arrangements on the front of the chassis frame. Vertical pillars at the frame corners carry triangular-shaped pivoting arms, swinging about one corner of the triangle. A transverse track rod joins the inner corners of these slave arms and from the outer corners links run rearwards at about 45 degrees to steering arms on the hubs. A rack-and-pinion unit is mounted on the front of the chassis at an angle and the left-hand end of the rack is also fixed to the chassis, which means that the free end of the rack acts as a push-pull arm and this is coupled to the right-hand triangular swinging member.

The Lotus suspension bears no resemblance to normal Grand Prix practice, consisting of fabricated rocker-arms operating inboard coil springs both front and rear, the colour photographs in the centre-spread showing the shape of these rocker arms quite clearly. The water radiator is carried well forward of all the mechanism and a long wedge-shaped nose cowling covers it, the thin end of the wedge almost scraping the ground. Both sides of the chassis monocoque contain fuel bags, with another in the rear cross-member, between the engine and the rear cross-shaft housing. Whereas the Matra 4-w-d could easily be mistaken for a normal bulbous MS80, the Lotus 4-w-d presents a very new look to the Grand Prix scene, though it is a look that has become very familiar at Indianapolis and in U.S.A.C. racing. Four-w-d must eventually take control of Grand Prix racing and apart front the Matra and the Lotus that appeared at Zandvoort for the first time, the McLaren and the Cosworth cars are following. Probably the first team to be successful will be the one who is sufficiently convinced about 4-w-d to scrap their two-wheel-drive cars and insist that their drivers stop chopping and changing about and get on with the new cars and develop new driving techniques applicable to the new systems. Moss, Clark and Andretti, who all drove 4-w-d with impressive results, insisted that new driving techniques were essential. At the moment there is little point in asking what they are for there has been insufficient 4-w-d racing for any clear cut driving theories to have been developed. What is clear is that any driver who approaches 4-w-d racing with 2-w-d mentality will not get the most front his car.—D. S. J.