Pirelli talks Abu Dhabi night race challenges
Pirelli says the challenge for its tyres at the Yas Marina circuit in Abu Dhabi, the penultimate round of this year’s Formula One World Championship, will be in maintaining their performance throughout the operating range of temperatures. The race will be run from dusk to nightfall, meaning that track temperatures tend to fall and then stabilise. This affects pace, degradation and wear. In addition to the manufacturer’s 2011 specification tyres, the Abu Dhabi circuit will act as a proving ground for Pirelli’s latest range of development tyres, echoing last year’s first appearance on a contemporary Formula One car.
In terms of the track, Pirelli says the sectors test a range of performance characteristics, including the flowing sequence of bends that start the race, in which the car is subjected to sideways accelerations of 4G, with the outside tyres guaranteeing grip along with the best possible road-holding at speeds of 250kph.
Throughout the longest straight of the lap, the structure of the tyre is challenged due to the high speeds reached with full throttle maintained for around 15 seconds. The aerodynamic downforce generates a loading of 800 kilograms, entirely absorbed by the tyre structure, which at the same time has to soak up any bumps and imperfections in the track surface.
For Turn 11, the cars go from 300kph to 90kph in 110 metres. This is a 5G deceleration, taking the drivers into a slow series of esses that have to be driven with maximum precision.
The final section of the lap requires an optimal balance from the car. A sequence of curves progressively heats up the tread pattern. The tyre temperature can reach 130° degrees centigrade while still ensuring the highest possible levels of grip, durability and car control that are vital for Abu Dhabi’s asphalt.
2012 tyres ready for public bow after di Grassi tests
While the season has been taking place, Pirelli has also carried out 10 days of private testing with test driver Lucas di Grassi and a Toyota TF109 that has been modified to reflect the latest technical and aerodynamic regulations. The tests took place over four circuits – Istanbul, Barcelona, Jerez and Monza – covering on average 700 kilometres per day. The initial results of that work will be seen on Friday and during the young driver test.
The tests have concentrated on refining the latest evolutions of the P Zero tyres that will be seen next year, using a combination of computer simulation, driver feedback, and data analysis.
A new tyre is first virtually simulated using computer-based mathematical models by the research and development division in Milan, before a series of bespoke physical prototype tyres are made in the Pirelli factory at Izmit in Turkey. Before these prototypes are put onto a car, they are subjected to a number of machine tests in Milan that push the tyre’s limits way beyond the usual parameters. Only then does it take to the track.
During a tyre test, the test driver tries out each new tyre for a set number of laps but in between runs he will constantly return to a reference tyre: in this case, the existing compounds that have been used this year. This means that Pirelli’s engineers have a consistent base from which to work, and they will also know if performance has been influenced by any other factors apart from the new tyre that is being assessed.
As well as the raw data that is collected during a tyre test – such as temperature, loading and lap times – the driver gives his subjective impression of the tyre, taking into account warm-up time, driveability and handling precision.
Pirelli says that the driver’s impressions are often backed up by the data, meaning that often his idea of how the tyre could be improved further is considered alongside the collected objective measurements. Using the conclusions reached, the engineers can adjust the compound and structure to achieve the desired results – which can then be tested and verified again with a different prototype tyre. With only 10 days of official testing allowed prior to the start of the 2012 season, the work carried out by di Grassi and the test team is vitally important.
Pirelli’s motorsport director Paul Hembery commented: “The pace of development in Formula One is phenomenal and so it did not take the teams very long at all to fully understand our tyres and make the most of their potential. This means that in a way we have had to constantly reinvent ourselves in order to keep on pushing the envelope and next year’s tyres represent the next step, with yet more performance. The feedback and information that we obtain over the Abu Dhabi weekend and test will be very important as we continue to develop our 2012 range of P Zero tyres.”