Chinese GP: Renault technical preview

Renault tech file: Shanghai

China is one of the modern breed of Formula 1 circuits and offers some unique challenges to the teams and drivers. Although it does not feature much elevation change, there is a wide variety of challenging corners -- from slow hairpins to high speed sweepers, and some extremely tricky sections. As is generally the case with the most modern circuits, it is also very wide, which can make it difficult for the drivers to find the right line. The facilities are excellent, and provide the teams with the best possible conditions in which to approach the race weekend.

Chassis

Tyres: In general terms, Shanghai is a tough circuit for the tyres. Not only are the front tyres heavily loaded by corners such as turn 1 (left front), 7 (right front) and 8 (left front), but the numerous slow corners mean the rear tyres are worked hard under traction, accelerating away. Turn 13 also deserves a special mention, where the front left tyre is heavily loaded through this 270 corner, all the while accelerating and putting high lateral and longitudinal loads through the rear tyres. It is always a difficult challenge to find the optimum solution in terms of tyre choice for this circuit.

Aerodynamics: As with many modern circuits, Shanghai includes a mixture of high-speed corners and long straights which means the level of aerodynamic downforce has to be judged very carefully to protect position on the straights, without compromising grip in the corners. Just as in Bahrain and Hockenheim, aero efficiency comes to the fore, and ideal levels of downforce are sometimes compromised in favour of straightline speed to avoid being overtaken in race conditions. The engineers will pay careful attention to the cars' relative straightline speed during practice in order to choose the optimum aero level for qualifying and the race.

Suspension: In mechanical terms, it will be important to find the correct compromise that gives the driver confidence in the car's handling over the full race distance. Shanghai is a circuit that features a lot of braking from high speed, some fast corners and plenty of acceleration phases. Combined with a number of changes of direction at both high and low speed, it means we will generally run a stiffer, more reactive set-up at the front of the car -- and then make the springing softer at the rear, for optimum traction and braking stability. In particular, we concentrate on making the car stable under heavy braking and on partial throttle openings, as the driver is often having to turn and brake/accelerate simultaneously, for examples in turns 1&2 or turn 8.

Engine

Power: The less powerful engines, combined with stickier tyres, mean that the engines spend a higher percentage of every lap at full throttle than they did in 2005. However, the impact of this change is lower than average in Shanghai -- owing to the fact that the circuit includes a large number of slower corners, and relatively few high speed turns at high throttle openings. For the 2006 season, the average increase in the time spent at full throttle has been of the order of 17%, whereas at Shanghai it will be only 11%, meaning a total of 61% of the lap is spent at maximum throttle.

Cooling: This extra time spent at full throttle also demands increased cooling, as the engine is rejecting more heat proportionally than the V10. However, with ambient temperatures in Shanghai expected to be in the mid to high 20s, this will not pose any problems given that the team has already negotiated the demands of the hot European summer without any problems.

-credit: renault