Pirelli: Intelligently testing philosophy
The hard and the soft tire will be the prime and option choices for the Malaysia, as was the case in Australia, but with rain such a common feature of Malaysia, the intermediate and wet tires are likely to take center stage as well.
The intermediate tire, distinguished by light blue markings, has a tread that is characterized by light grooves across the whole surface of the tire.
The wet tire, with orange logos, has an asymmetric tread design. The pattern is denser on the outer edge of the tire, while a centre channel and two smaller channels of the inside of the tire help to disperse water more effectively.
The amount of water displaced varies according to the depth of the grooves. The grooves on the intermediate tire are three millimeters deep, meaning that they can cope with standing water that is around two millimeters deep.
Any more water than that and the wet tire is required. The moment at which it becomes quicker to switch from the intermediate to the wet tire and vice versa – the ‘crossover point’ – is of vital strategic importance, and will hold the key to the teams’ tactics in Malaysia.
The wet tire has a tread depth of five millimeters and is able to cope with a level of standing water of up to five millimeters before aquaplaning sets in. One of Pirelli’s wet tires will clear up to 60 liters of water per second at 300kph (186.411 mph), meaning that a Formula One car at full speed will clean up 240 liters of water per second.
The intermediate tires by contrast clear 20 liters of water per second, as opposed to a road car tire that can only clear 10 liters per second – but at much slower speeds.
Malaysia presents a stark contrast to the first Grand Prix of the year in Australia, with hot and humid weather matched to a much more aggressive surface. This should lead to three or four pit stops during the race.
The Sepang circuit is 5.543 kilometers (3.44 miles) long, with the total of 56 laps that total 310.408 kilometers (192.878 miles). The circuit is well known for being tough on tires, and that is evident from the very first hard braking area into turn one.
The second turn is even tougher: the unevenness of the surface and the stiff suspension means that the inside wheel often lifts, putting all of the load on the outer front tire.
After the opening complex of corners there is a long right-hand bend taken at 250kph (155.342mph). This turn tends to result in understeer, forcing the driver to make a correction. The front left tire, which does all the work here, is subjected to a vertical load of 830 kilograms (1829.836 lbs).
As well as the two main straights, unusually separated by a hairpin bend, there is a quick succession of fast corners that impose a lateral acceleration of more than 3G on the car and tires. The left-rear tire temperature gradually rises to a peak of 150 degrees (302 degrees Fahrenheit) on the inner edge while accelerating out of the corner. The famous hairpin bend between the two straights is not only crucial, but a key area of stress for the tires, combining braking, turning and acceleration at the same time.
Pirelli come to grips with hot weather, experimental compound
As we mentioned earlier, Pirelli brought a new experimental compound to testing Friday. We were intrigued by how many teams would actually test the tires and provide Pirelli with quality data in which to help them develop the tire compound further. They picked hellish conditions in which to test them. With track temperatures that climbed to 124 degrees Fahrenheit and an ambient temperature of 99 degrees Fahrenheit it a wonder that any tire could survive the punishment F1 delivers.