Features - Technical
APRIL 12, 1999
BY PETER WRIGHT
Every so often in Formula1, the combination of regulations and the status of the participants come together in such a way that it is the heart of the car, the engine, that for a while becomes the key component.
Last year's regulation changes to the overall dimensions of the cars, and the re-dimensioning and grooving of the tyres have been absorbed by the engineers. The Bridgestone-Goodyear tyre war is temporarily over. Big changes to the aerodynamic L/D are becoming harder and harder to achieve, with little scope for innovation. Whenever other factors stabilise, it is the engine that re-emerges to dominate overall performance.
Intensifying this situation is the ever-increasing interest in Formula1 by the major motor manufacturers. With Mercedes, Fiat, Ford, and Peugeot actively involved, Honda and Renault indirectly so, and BMW poised to join in, we are also about to see Honda and Toyota, and maybe Mercedes and Ford (Jaguar) actually become full-blown participants, where only Fiat (Ferrari) had previously taken that step. It is too early to tell whether it is the importance of the engine and the suppliers' desire to control the destiny of their products, or the increasing need to intensify engine development and the high costs involved, that has brought about this situation. Whichever way round it is, there is a power war under way, and top dollars are being spent on the weapons.
Ruling the roost at the moment is the Mercedes-Benz F0110H 3.0litre V-10, designed and built by Illmor, and fitted to the McLaren MP4-14. It is rumored to be producing around 820PS at up to 18,000rpm, and to weigh under 100kg. Mercedes have suddenly cut right back on published information about their engine - a sure sign that they take the escalating power war very seriously, being especially sensitive to BMW's impending arrival. Ford, out of a now wholly-owned and re-juvenated Cosworth, and Ferrari are next, with Ford scoring on low weight but currently unreliable, and Ferrari's engine appearing to be bullet-proof. Power continues to climb the RPM curve, yielding over 4.5PS for every 100rpm increase, while thermal, volumetric and mechanical efficiencies are maintained. Bore:stroke ratios are over 2.25:1, and the resulting disc-shaped combustion chamber presents a real challenge. Combustion research, friction reduction, achieved through specialised and extremely secret surface finishes and coatings, and detail design and analysis of the highly stressed bottom-end components are the key areas in the quest for ever-higher RPM.
However, it is not power but engine weight that is providing the McLarens and Stewarts with much of their superiority. The current cars are under-tyred at the rear and tend to be unstable, especially when braking hard as the driver tries to turn into the corner. To put as much tread width on the road as is permitted by the regulations means that the ratio of tread width front-to-rear, is 46:54. With a car that is on the 600kg (including driver) weight limit, it is hard to get more than about 43% of the weight on the front. To bring the weight distribution more in line with the tyres, weight must be removed from behind the CG and placed ahead of it, and there are few components that can be moved without increasing overall weight. Lengthening the wheelbase, by moving the rear wheels rearwards will do it (around 1.5% per 100mm), but weight goes up and it may hurt vehicle dynamics. The solution Mercedes and Ford have provided for their teams is a small, light engine.
McLaren have built an extremely light car, some say as much as 60+kg under the limit. If half that has come from the engine and gearbox, and that 30kg of the 60+kg of depleted uranium ballast that must be fitted, is placed ahead of the CG, they will have moved the weight 2% to the front. The McLarens and the Stewarts are the only cars that look as if they are stable, giving their drivers a chance to really brake deep into corners, where the time for a quick lap is so often found.
By the time this power war is over, Formula1 engines may well be producing 900PS at 20,000rpm, and weigh under 90kg. That is 300PS/litre, 10PS/kg, and over 1650 explosions per second. They should sound good!