New Tyrrell Formula One car
All things being equal, though in motor racing they seldom are, the 1974 Tyrrell Formula One should have made its first public appearance at the Spanish Grand Prix as these words are being read. When Ken Tyrrell had his first car designed by Derek Gardner in 1970 he did not think he was going to become a manufacturer, with a series of cars, or at least that is what he said. Since the introduction of cot Tyrrell at the Oulton l'ark Gold Cup meeting in 1970, especially for Jackie Stewart, there followed 002, 003, 004, 005, 006 and 006/2, and at times Elf 'Team Tyrrell fielded three cars in certain races. Now a new series of cars has begun with 007 and 007/2, for the new Tyrrell drivers Scheckter and Depailler. The first of the new cars was presented to the Press at an Elf-sponsored party in Paris in early April and a small group of Press people were allowed to inspect the car as it was being finished off in the small workshop of the Tyrrell Team in the woodyard of Ken Tyrrell, Timber Merchant, at Ripley in Surrey.
There is nothing unduly revolutionary about the new car as far as conception is concerned, though everything is newly designed, but it represents Gardner's interpretation of all the knowledge gathered with the earlier cars together with the results of various experiments carried out over the last eighteen months. The central monocoque section is in aluminium with flat surfaces everywhere and side pods of fibreglass containing the obligatory deformable structure and the ducts for the side mounted radiators are attached to the monocoque. The wheelbase of the new car has been increased from 96 in. to 102.08 in. and this extra length has been introduced between the engine and the back of the cockpit, unlike the McLaren where it has been introduced between the engine and gearbox. Gardner tried this idea on one of his earlier cars and decided it was not the was to go in the interests of weight distribution; also, he needed space behind the driver for part of the fuel load. Around this space is a large roll-over hoop, which is like earlier Tyrrells in being a full oval, running under the car as well as over it, and it forrhs the anchorage for numerous vital components such as radius arm mountings as well as mountings for the Cosworth V8 engine. The Hewland gearbox has inboard brake mountings and an alloy casting under the sump acts as a reservoir for the gearbox oil, which has Gardner's own dry-sump system, and at the same time as pick-up points for the lower wishbones. The Howland gearbox normally relies on the gear wheels splashing oil about the place for its lubrication, which Gardner was never very fond of, so he designed his own dry-sump system with pressure jets squirting the oil where it was most needed.
The rear suspension is by longitudinal torsion bars within torsion tubes (like a 1970 Lotus 72) actuated by links from the conventional rear end layout. At the front the suspension is by fabricated sheet steel wishbones with a tubular link front the lower one operating a rocking arm pivoted above the upper wishbone, the inner end of this arm operating on an inboard coil spring/damper unit. Front brakes are inboard, (everyone comes round to Chapman thinking in the end, it seems) following experiments carried out on earlier ears and have an interesting cooling feature in that an air duct from the nose takes air into the hollow fabricated brake disc bearing mounting and then into the centre of the disc from where it is centrifuged through the radial slots in the brake disc. Lockhead brake calipers, with four pads, are of a new design especially for mounting on the lower part of the disc under the car and in the air stream.
Again, as ,a result of earlier experiments, the nose is wedge-shaped and fairly pointed, the 'Tyrrell "bluff" full-width nose being abandoned. At the ends of the nose fins are tall slim air deflectors channelling the air between the front wheels and the bodywork, in the direction of the intakes for the side radiators. The rear aerofoil is on the latest "banana" shaped pattern and the engine air intake is tall and thin rather than short and fat. While there is nothing new or revolutionary about the new Tyrrell it is all of sound, logical design and sterns from practical, clear thinking, which has been the hallmark of Ken Tyrrell's Formula One team since its inception. With support from Goodyear tyres, Ford-sponsored engines and Elf petrol and oil the Tyrrell is still highly respected in Formula One, even without Jackie Stewart as the number one driver, and in spite of the sad and sudden loss of Francois Cevert at Watkins Glen last year, just when he was lined up to take over team leadership. D.S.J.
Rocker arm operation of the inboard front suspension gives rising rate characteristics.