The fourth race of the Formula One season takes place on Sunday at the 5.4-kilometer Bahrain International Circuit,in the desert about 30 kilometers southwest of the capital city of Manama.
The demands of racing in the 3.3-mile desert circuit are like none other on the calendar,with the ambient temperatures expected to rise up to 35 degrees Celsius,or 95 degrees Fahrenheit,and the track temperature reaching 45 degrees Celsius or more.
This means that tyre temperatures also rise,making tyre management once again a crucial factor at this race.
The evolution of the track grip,on a track that is not used much throughout the year apart from for this Grand Prix,is almost impossible to predict. Adding to that uncertainty is the fact that desert sands spray across the surface and reduce grip. The track surface is made of granite imported from Wales and is one of the most abrasive and wearing circuits for Formula One tires.
In Friday practice,we need to try and find a good car setup to maximize the long-run performance for the race so we can keep the tyres alive longer than others, said Valtteri Bottas,a driver at the Williams team.
The Pirelli company intentionally created a much softer,more quickly degrading rubber for the tyres this year. But at the second race of the season – in Malaysia in March – Pirelli decided to change its original choice of tyres for Bahrain from the soft and medium level of hardness to the medium and hard level. The big challenge in Bahrain is normally the heat, said Paul Hembery,the Pirelli racing director. And this accentuates the amount of energy going through the tyres.
Traction and braking are the two key aspects of Bahrain, he added,both of which are very demanding on the tyres,and I would expect to see a three-stop race from most teams,as was the case last year. Degradation rather than actual wear will decide the strategy.
The car setup for this circuit is all about finding that grip,but also about dealing with the four straight sections of the track raced at more than 300 kilometers an hour. Each straight is followed by a medium-or slow-speed corner,taken in fourth gear or less. Eleven of the circuits 15 corners are taken at 200 kmph or less,in fourth gear or lower. According to Pirelli,in the first corner the cars decelerate from 315 kmph. to 65 kmph. in just 130 meters,or 425 feet,and three seconds,placing a force on the tyres equivalent to around 4.5 g.
Car setup is a compromise between straight-line speed and favoring grip in cornering. The car requires fairly high levels of downforce in Bahrain,so a lot of the rear wing is used. The high temperatures mean that the air is less dense and less effective aerodynamically.
The suspension needs to be sufficiently compliant for the traction requirements,according to James Allison,the technical director at the Lotus team. He said the traction demands from the lower-speed corners also require a focus on enabling maximum use of the mechanical grip as opposed to the aerodynamic grip from the tyres.
The Bahrain circuit is a real challenge,particularly for the tyres,with overheating,and also the sand on the track,but this helps make it unique, said the Mercedes driver Lewis Hamilton,a former world champion. The layout has a great combination of fast,slow and medium corners,which make it tough for the drivers and the car,so it will be a true test fro us, he added. The circuit is also one of the hardest on the engine because of the high temperature and low humidity more than because of the straights.
It ranks in the middle range of circuits in terms of engine power,as the drivers are on full throttle for 50 percent of the circuit during the race and 57 percent during qualifying.
The body work may have to be slightly opened to aid the cooling configuration,while the aridity increases pressure within the cylinder chamber,which can cause internal failure, said Remi Taffin,the head of track operations for the Renault engine manufacturer. We can counteract this by tuning the engine.
Because it is one of the most difficult circuits for braking,it is also particularly difficult in terms of brake cooling. There are eight braking areas around the lap,and five are heavy braking zones.
The wind around the unprotected desert circuit also plays a role in aerodynamics. Finding the right aerodynamic setup during the Friday and Saturday practice sessions is also crucial.
It is not easy to find a good setup as you do experience the track surface changing over the weekend and sometimes the wind can affect the balance of the car too, said the former world champion Kimi Raikkonen.