This weekend the teams race on the new Buddh International Circuit, located about 50 kilometres south east of New Delhi. The track has similarities in composition of corners to a number of F1 circuits but it has unusual features too. So how will the teams tune the cars in to the circuit and what will the winning race strategy be on Sunday?
Here is a comprehensive guide to the considerations the F1 engineers will be looking at when deciding how to attack this weekend’s race.
Buddh International – 5.125 kilometres. Race distance – 60 laps = 307.249 kilometres. 16 corners in total. Average speed 210 km/h. A new circuit hosting a Grand Prix for the first time
Aerodynamic setup – High downforce. Top speed 320km/h (with DRS open) 308km/h without
Full throttle – 70% of the lap time (est) Total fuel needed for race distance – 161.6 kilos (high). Fuel consumption – 2.65 kg per lap (ave)
Brake wear- average.
Loss time for a Pit stop = 15.5 seconds (est)
Total time needed for a pit stop: 20 seconds (est)
Fuel effect (cost in lap time per 10kg of fuel carried): 0.35 seconds (ave/high)
The track is a combination of mostly slow speed corners and some long straights, which leads to a reasonably high average speed. The first sector of the lap is stop-start, with two straights intercut with hairpins, while the middle sector is a flowing section featuring some faster corners, including the banked Turn 10/11, which engineers estimate will be approaching the G force on the drivers and loading on the tyres of Turn 8 in Turkey.
The track has a lot of elevation change, rising 14 metres from Turn 1 to Turn 3, which contributes a little to increasing the fuel weight penalty, in other words the weight of every 10kg of fuel slows you down more than at some other tracks.
During practice and qualifying the adjustable DRS wing can be used for approximately 62% of the lap, roughly similar to Spa. In the race it will help overtaking on the straight. With 20 metre track width, overtaking should not be a problem at Buddh.
Teams will have been using simulation tools in the factories to establish baseline items such as gear ratios, wing levels, springs and cooling requirements. But they can only really understand the grip level of the track and the tyre wear rates by running on the circuit. It would appear that the track surface is quite smooth and there are no real bumps.
The total fuel needed for the race is high at over 160 kilos, which will test the fuel tank size of some teams, especially with the higher fuel consumption brought about by exhaust blowing diffusers. Recently we have seen an increasing number of drivers running out of fuel on the slow down lap after the chequered flag. We may well see that again in India.
The Indian Grand Prix is the 17th round of 19 in the 2011 FIA F1 World Championship. Sebastian Vettel has clinched his second consecutive world championship and won four of the last five races, but the Red Bull team has lost its 100% record in qualifying, as Lewis Hamilton’s McLaren took pole in Korea. However on race day the Red Bull was still the fastest car and the Buddh Circuit should suit its car.
Most teams are using the final races of the season to test out ideas and components for next season, so relative performance can change, for example Ferrari were not particularly fast in Korea, until the second half of the race.
The forecast for the weekend is stable with temperatures in the mid-20˚Cs to low 30˚Cs and track temperatures up in the low 40˚Cs.
Pirelli tyre choice for India: Soft (yellow markings) and Hard (silver markings). This combination was seen in the first five races as well as Silverstone.
Although the teams have the basic information about the circuit, the radius of each corner and length of the straights, they do not yet have a good feel for the abrasiveness of the track surface and the level of track improvement over the weekend. This will be crucial to making the right calls on Sunday. Teams will use the extra set of Pirelli soft tyres available for practice on Friday to learn as much as possible about tyre degradation.
Simulations show that the circuit provides a similar level of tyre challenge as Silverstone and Korea, with 80% of the tyre energy of Suzuka. The high temperatures are likely to lead to tyre blistering, particularly on the shoulder of the tyre and camber angles will have to be conservative to cope with heat build up the long straights.
The combination of soft and hard tyres is a very conservative one; it is a new track and Pirelli don’t want to take any chances. The combination has not been seen since Silverstone, (which started in wet conditions so the hard tyre was not used) and earlier in the season, in Barcelona for example, we saw a performance difference of over 2 seconds between the two compounds.
This will mean that drivers will want to qualify on the soft and do most of the race on it, with probably no more that 10 laps on the hard tyre at the beginning or end of the race.
The main taking point is likely to be the fast Turns 10 and 11: similar in its characteristics to the famous Turn 8 in Turkey, although tightening, rather than opening out and therefore slower. It will put a lot of lateral energy through the tyres. The corner is a right hander, so it will hurt the front-left tyre in particular and this could be a limiting factor in the race.
Wheels spinning under acceleration out of the many low speed corners will also take quite a bit out of the rear tyres.
Whereas the Bridgestone hard tyres were better at coping with high temperatures than the softs, with Pirelli it is the other way around.
The pit lane at Buddh is long at 600 metres, but simulations show that it can be negotiated in 20 seconds including the stationary time, so it’s not as bad from a strategic point of view as might be imagined.
Drivers will want to spend as little time as possible on the hard tyre, as it will be so slow in comparison with the soft. So strategists will be planning around 10 laps or less on it. For top ten drivers, who must start the race on their qualifying tyres, they will take the hard tyre at the end of the race; for those outside the top ten, who can choose their starting tyre for the race, we may see some opting to get the hard tyre out of the way early, as the pace will be slower with traffic in the first ten laps than when the field has spread out in the last ten laps. Heidfeld (Renault), Sutil and Barrichello tried this strategy in Barcelona.
On paper therefore, allowing for that short stint on hards, strategists will be planning a three stop race, but the game will be to establish whether it’s possible to cut that down to two stops, by making the softs last longer and using the hard for a little longer. Teams like Toro Rosso and Sauber, which have made a speciality of extending the opening stints and gaining track position in the process, may well try it again here.
Otherwise there will probably not be a big variation between strategies this weekend.
Chance of a Safety Car
As there is no data this is yet to be established. However we have seen a number of safety cars around one third distance in the races this season, which have mixed up the order. A Safety Car at Buddh would help drivers attempting to make one less stop.
Starts are a critical part of the race and strategy can be badly compromised by a poor start, while good starts can make strategists change their plans in the hope of a good result.
In Korea, the winners off the line were Kovalainen, Barrichello and Ricciardo (gained 3 places) while the losers were Button, (lost 3 places), Buemi and Senna (lost 4 places). Senna’s starts have been a problem since he came back to F1 with Renault. He’s now lost 19 places in just five races. Compare that with Ricciardo, who has gained 10 places off the start in his eight races.
As far as 2011 start performance is concerned drivers have gained (+) or lost (-) places off the start line this season on aggregate as follows:
+25 Schumacher *
+17 Buemi #
+9 Di Resta,
+6 Massa, Heidfeld ******
-8 Hamilton, Rosberg*****
-9 Sutil ##, Maldonado
-14 Perez ###
– 23 Webber
* Schumacher had one bad start in Australia, losing 8 places but since then has been the season’s outstanding starter. He gained 9 places in Spa and four in Monza.
** Kobayashi lost 10 places in Spain, prior to that he had gained 8 in 4 starts.
*** After losing places in the first three races, Alonso has reversed that trend. His starts in Barcelona and Monza were outstanding.
**** Petrov had a good record until he lost 4 places at the start in Valencia. He was on a +2 balance before Monza where he was taken out at the start.
***** Rosberg lost four places at the start in Silverstone and was on a +6 balance before Monza where he was taken out in the first corner
****** Heidfeld had gained 20 places but lost 12 at the start in Germany
******* Di Resta had consistent start form and gained 7 places in the first nine races, but lost 12 at the start in Germany.
# Buemi made up nine places at the start in Hungary having started 23rd on the grid
## Sutil had a positive start balance until Hungary where he lost 12 places at the start
### Perez lost nine places off the start in Hungary.
#### Alguersuari was doing well with a +6 record prior to Spa, where he was hit by another car and lost 18 places. In Monza he gained 7 places at the start.
Pit Stop League Table
Of course good strategy planning also requires good pit stop execution by the mechanics and there have been some amazing performances; we have seen tyre stops carried out in less than two and a half seconds this year.
The table below shows the fastest single stops in the recent Korean Grand Prix. Allow approximately 17 seconds for “loss time” ie the time it takes the car to travel down the pit lane and enter the pit box. The difference between that and the time shown below is the stop time, plus the driver’s reaction time when released.
Red Bull’s pit crew were the only team to break 20 seconds in Korea, while Virgin slipped to the bottom of the pile, below HRT.
1. Red Bull – 19.985
2. Mercedes – 20.091
3. McLaren – 20.584
4. Ferrari – 20.639
5. Force India – 21.060
6. Renault – 21.163
7. Sauber – 21.225
8. Williams – 21.569
9. Lotus – 21.951
10. Toro Rosso – 21.992
11. HRT – 22.092
12. Virgin – 22.412