Silverstone - the technical requirements 06 Jul 2007
The arrival of the V8 engines last season, coupled with ever-rising levels of downforce, transformed the challenge of the Silverstone circuit. Corners previously requiring downshifts were taken with just a lift of the throttle, and indeed the first half of the circuit, all the way to Vale, requires very little braking at all. The engines are under prolonged load and indeed, the full throttle percentage per lap jumped by 12 percent between 2005 and 2006.
While the less-grippy tyres used in 2007 will see that figure decrease, it still makes this a tough track for every part of the car. Corners range from 180mph (290km/h) sweepers to the long, slow complex at the end of the lap - and the car must also cope with the bumpy surface and capricious, gusting winds. One word to describe Silverstone? Selective, for both cars and drivers. Renault reveal how they plan to get the most out of the R27 this weekend...
Downforce levels at Silverstone are medium-high - the same as those used one week ago in Magny-Cours, when the R27 confirmed its recent progress in terms of pure performance. The downforce is required for the quick corners in the opening part of the lap, and the relatively short straights and short braking zones mean that any deficit in straight-line speed is unlikely to see competitors overtaking you. The lack of heavy braking also means we run some of the smallest brake ducts of the year to optimise aerodynamic performance.
Ride is an important characteristic at Silverstone, where maintaining consistent aerodynamic performance is so critical for performance in the quick corners. The surface is quite bumpy, and nowhere more so than under braking for Turn Eight, where the uneven surface can unsettle the car. The drivers also tend to drift out onto the kerbs exiting the quick corners in order to take the fastest line, which can make the circuit seem bumpier than it is.
We run the car with a forward mechanical balance at this circuit - essentially, with a stiff front end and softer rear end. The stiff front gives the car a good change of direction in the high and slow speed corners, while the softer rear end gives better grip under traction, exiting Turns Nine, 11 and 16 in particular.
Tyres are always given a hard time at a circuit including numerous high-speed corners, and this means Silverstone, along with Spa and Sepang, is among the toughest tracks of the season. Bridgestone will offer the 'medium' and 'hard' compounds from its 2007 range of Potenza tyres in order to cope with these challenges.
As a former airfield, Silverstone is inevitably exposed to the wind - and this can have a big impact on car performance. Gusting wind alters the aerodynamic balance of the car and makes handling unpredictable, particularly in the high-speed corners. The driver must be able to judge the direction and strength of the wind, and adjust his driving accordingly.
The percentage of the lap spent at full throttle has actually decreased for 2007, with the advent of the single tyre supplier era, decreasing from 71 percent to 68 percent for 2007. However, Silverstone remains one of the harder circuits in terms of the demands it places on the engine, which also needs to be responsive at high revs as the drivers take the quick corners on either full or partial throttle. In terms of cooling, we have already tested at this circuit, and are well-prepared for every eventuality.
Fuel consumption is high at Silverstone, as is the time penalty for carrying extra fuel weight. This means that it is a circuit where strategies rarely vary from the norm, as two extra laps of fuel, for example, could cost nearly two tenths per lap. Expect to see most teams running a standard 2007 strategy of two stops, which are generally slightly forward-biased for the front-runners in order to ensure good grid position and clean air in which to race in the early stages. With overtaking nearly impossible at this circuit, track position is all important.