During the practice for the British Grand Prix at Brands Hatch the B.R.M. team produced an experimental 4-wheel-drive car, which was driven by Richard Attwood for test purposes. Evolved in conjunction with the Ferguson Research firm this vehicle is a travelling test-bed for ideas that will no doubt he incorporated in the 1966 B.R.M. Grand Prix car. It was constructed from existing components from last year’s B.R.M. Formula One cars and the Ferguson P99 research single-seater that proved the point of 4-wheel-drive back in 1961. As a basis for this experimental car an old B.R.M. space-frame was modified In take a V8 Grand Prix engine turned through 180 degrees, so that the flywheel and clutch assembly were just behind the driving seat. A special gear-train steps the drive across to the left of the cockpit and a shaft runs forward to a 6-speed B.R.M. gearbox mounted to the left of the driver’s knees. Attached directly to this gearbox is a unit containing the Ferguson centre-differential and controlled-slip clutch unit and the gear train providing fore-and-aft propeller shafts. The front shaft is attached directly to the front-wheel Ferguson drive unit, containing crown-wheel and pinion and differential unit, and open shafts take the drive to the wheels. The rearward running shaft from the B.R.M. gearbox/Ferguson control mechanism runs along the side of the driving seat, under the left-hand cylinder head of the V8 engine, where a steady bearing is mounted, and thence to the rear-wheel Ferguson drive-unit, identical with the front one, and again by open shafts to the wheels.
Whereas the P99 used inboard brakes the B.R.M. has them mounted outboard, but this is merely because existing suspension units, wishbones, etc., are used in the interests of economy and time. The front-wheel drive shafts pass through the fabricated hub carriers via constant-velocity joints. At the moment 15 in. wheels carrying 6.00 Dunlop tyres are used, but again this a question of using existing parts, the important thing being to get the layout and system worked out and functioning properly, after which detail design work can be started. As it stands at present the car is unduly heavy and is not taking advantage of the Ferguson 4-w-d layout as regards size and weight, but this will follow once the acceptance of the principle has been achieved. The driving position is offset to the right of the cockpit, to allow for the propeller shaft and the engine-to-transfer-box shaft, and the engine is set at a slight angle in the chassis for similar space reasons. Fuel is carried in pannier tanks and oil in a tank at the rear of the car, while water radiator and battery are mounted right in the front of the nose. The intention is to run the car as a test-bed for information, with Attwood as the driver as the 4-w-d principle obviously needs a new technique of driving, as Ferguson’s discovered with the P99 and it is better to leave the team-drivers concentrating on winning races with the orthodox B.R.M. cars, and let a new and uninhibited driver do the test-bed work. This interest by B.R.M. in 4-wheel-drive principle for Grand Prix racing will undoubtedly cause other teams to take note, but in fact the Ferguson P99 pointed the way in 1961 but the Grand Prix world was then too conservative to take the lead. Congratulations to Tony Rudd and the B.R.M. designers for starting this new and interesting lead in the technical field of Grand Prix racing. It has probably been forgotten that the 1954 Mercedes-Benz W196 was designed for 4-w-d with the option of rear-wheel-drive or all-wheel-drive being at the choice of the driveir simply by operating a foot-controlled solenoid-switch. Time unfortunately beat this project and the W196 appeared as a rear-wheel-drive racing car, albeit a very successful one. – D.S.J.