Focus - more grip or more power? 31 Oct 2003
Tyre performance is the single fastest way to improve a Formula One car's lap time. Engine performance has an impact of course, but it requires a much larger percentage increase in horsepower to achieve the same reduction as an equivalent increase in grip.
As an illustration, take two very different circuits - the Hungaroring and Monza - the former tight and twisty, the latter a succession of long, fast straights. A five percent increase in power at Monza will reduce a theoretical lap time by 0.8s; at the Hungaroring by 0.4s. Conversely, raise grip five per cent and you gain 1.25 seconds at Monza and 1.94s in Hungary.
Upping a tyre's grip is not only the fastest way to increase performance, it is also the cheapest. However, the process of arriving at the right construction and compound is far from simple and is something Bridgestone and Michelin devote much time and money to.
While both may appear to have made big steps forward, equally critical to their progress is the teams' improved understanding of the dynamics that make the tyre work.
Aerodynamics also play an important role in getting the tyre to function and, just as importantly, getting it to survive. Decrease a car's drag slightly (equivalent to raising power) and you will make a small difference to lap time. Add a similar amount of downforce and the gains are far greater, as it helps the tyre enormously, particularly in medium-speed corners.
In fact, ignoring tyre degradation, over one flying lap the added downforce means the tyre is better everywhere, with better traction and better braking. Williams senior development engineer Frank Dernie has no doubt's as the tyre's contribution to a car's performance: "The tyre is probably the least glamorous part of the racing car but the most important, and it was just as true in 1980 as it is today."
So if tyres are so vital to a car's pace, what role does power actually play in the performance equation? "People love to know how important is the engine relative to the tyre, and what percentage does the engine provide and what percentage does the tyre provide," comments Williams technical director Patrick Head, "but the reality is if you want to be quick you've got to have everything working the best you possibly can."
(The above is an edited extract from a much longer feature, in which you can found out why grunt is, in fact, just as important as grip. It is available exclusively in the November issue of Formula 1 Magazine.)