The Indian Grand Prix from a tyre point of view

The Buddh International Circuit represents new territory for Formula One and Pirelli, in one of the fastest-growing automotive markets in the world. Tomorrow the drivers will experience the track for the first time: here are some of the biggest demands that the tyres are likely to face on the 5137-metre circuit, located just outside of Delhi.

The track

A new track means that the surface will be at first dirty and slippery, making it hard for the tyres to generate grip – especially during practice at the beginning of the weekend. The track evolution should be pronounced, meaning that the times will improve as the weekend goes on.

The first sector of the track includes a slight left-hand corner before braking for a right-hand turn. This destabilises the car under braking, making the front-right wheel go lighter than it would normally when braking in a straight line. This inside tyre tends to lock up close to the apex causing understeer; it also means that the outside tyre has to do all the work of steering the car and supporting the front.

On the main straight – one of the longest on the Formula One calendar – the DRS flap is open. The dirt on the track leads to wheelspin under acceleration. The surface temperature of the tyre climbs to over 100 degrees centigrade, placing a heavy demand on the tread.

Turn 10 is certainly the most demanding corner of the track. The wide radius and camber allow high speeds to be reached that take the tyres to the limit of adhesion and put plenty of energy through the loaded tyre.

Preparing for a new circuit

While every circuit is new for Pirelli this year, a track that has never been raced on before is particularly challenging, both because of the nature of a new surface and because of the lack of previous data.

At the start of the season, Pirelli had a certain amount of data relating to all the circuits on the Formula One calendar this year, both from the teams and organisers, and also from previous experience of testing or racing in other series.

The data supplied relates to the forces at work on the tyres; wear rates in the past, driver feedback and statistical information relating to acceleration, braking, weather conditions and previous race strategy – as well as many other vital parameters.

With a brand new circuit, there is no prior data at all, so the task of preparing for the race and selecting the nominations becomes much harder. This is why Pirelli has nominated the hard and the soft tyres for the inaugural Indian Grand Prix, so that every possibility is catered for.

In addition to this, two of Pirelli’s engineers inspected the Buddh circuit en route to the Singapore Grand Prix. They were among the first people to drive the complete circuit, but their work mostly consisted of looking at the track surface in detail.

They brought with them sophisticated laser measuring equipment, in order to assess the abrasiveness of the circuit by examining closely the spacing and shape of the stones that make up the aggregate. Several readings were taken from the machine, in order to ensure an accurate representation. Using these readings a virtual representation of the track from the tyre’s point of view can be created on computer.

Together with some asphalt samples from the new track, this allows Pirelli to calculate the likely wear rate and the effect of the asphalt on the tyres at different points on the circuit. Nonetheless, these are theoretical calculations that cannot replace real data, as the way that rubber is laid down on the track with 24 cars running over the course of a weekend is impossible to replicate.

On arrival at all the circuits – but particularly in India – Pirelli’s engineers walk the track, to check that what they observe corresponds to the data they have received. They are also looking for any potential problem areas, such as sharp kerbs, modifications to the circuit from previous years, or street furniture such as manholes on a road circuit.

Pirelli’s motorsport director Paul Hembery concludes: “There’s no doubt that preparing for a circuit that is completely new is more difficult than going to one of the established venues. However, the technology and know-how that we have at our disposal means that we can forecast some very accurate predictions without actually having raced at a circuit. Nonetheless, at a track where nobody has any previous information, we have to go with a conservative choice in order to cater for any possibility.”