Monday, 20 April 2015

A few details from the Silverstone Six Hours

The Silverstone Six hours was, for many, one of the best races ever in the World Endurance Championship: afterwards some were saying it was the best race they’d seen. Due to a family holiday, I wasn’t even there; but I did follow along with what was happening, and I would agree that it was an outstanding example of endurance racing in the current age.

In 2014, the WEC served up some splendid racing, but a combination of stability in technical regulations, a year’s worth of experience and development from the three leading LMP1 manufacturers and a few minor tweaks to the sporting procedures and the opening round of the 2015 season had action to keep everyone on their toes throughout the six hours.

It is a credit to the team behind the technical regulations that three very different configurations of car, one from each of the manufacturers, should end up in the top three finishing positions, separated by less than 15 seconds at the chequered flag.

That’s a percentage difference of less than 0.07%. The winning margin represents a difference of just over 0.02s per lap over the Silverstone Grand Prix circuit. If you want to make the comparison (and perhaps you shouldn’t) that is less than the difference between Hamilton and Rosberg, in identical F1 Mercedes. Consider this: each of Porsche, Audi and Toyota have different types of hybrid systems, different size of engine and even a different number of cylinders in their solutions to the best way to go racing.

Inevitably, though, you can break it down differently, and then, as I shall demonstrate, there are some bigger differences to be seen. A good way of analysing the outright pace of each car is to look at the best 20% of the laps completed under full green conditions and here are the results for the top six LMP1 cars.

No. Car Drivers Lap time
8 Audi Di Grassi/Duval/Jarvis 1m 42.173s
7 Audi Tréluyer/Fässler/Lotterer 1m 42.264s
17 Porsche Webber 1m 42.301s
18 Porsche Dumas/Lieb/Jani 1m 42.576s
1 Toyota Buemi/Davidson/Nakajima 1m 42.975s
2 Toyota Wurz/Conway/Sarrazin 1m 43.356s

It is interesting - and I must admit reassuring - that this clear pecking order is what I predicted following the Prologue at Paul Ricard last month. Whether this is a pattern that will change as the season progresses, remains to be seen.

Let us now take a look in a little more detail at the contributions of the individual drivers of the first three cars past the chequered flag and the stints that they completed, as here, as in so much else, different strategies are at play.

One of the ‘tweaks’ in the regulations referred to above limits teams to six sets of tyres per car for qualifying and the race (at least at Silverstone and Spa). This means that, at best, one set of tyres has to be used for a double stint: furthermore the tyres used in qualifying have to be used again, unless two sets of tyres are used for double stints. (This latter strategy is not necessarily impossible, and I believe was tried by at least one team at Silverstone.)

The following three tables show the race strategies employed by each of the podium finishers:

No. 7 - Audi R18 e-tron quattro
Stint Driver Laps Average Lap time
1 Benoît Tréluyer 24 1m 44.040s
2 Benoît Tréluyer 28 1m 43.367s
3 Marcel Fässler 28 1m 44.630s
4 André Lotterer 28 1m 43.162s
5 André Lotterer 28 1m 43.688s
6 André Lotterer 28 1m 43.806s
7 Marcel Fässler 28 1m 43.478s
8 Marcel Fässler 1 N/A
9 Marcel Fässler 8 1m 44.156s

No. 18 - Porsche 919 Hybrid
Stint Driver Laps Average Lap time
1 Romain Dumas 24 1m 43.943s
2 Marc Lieb 29 1m 44.442s
3 Neel Jani 29 1m 44.587s
4 Romain Dumas 30 1m 44.188s
5 Marc Lieb 30 1m 44.351s
6 Neel Jani 30 1m 44.171s
7 Neel Jani 29 1m 43.535s

No. 1 - Toyota TS040 HYBRID
Stint Driver Laps Average Lap time
1 Sébastien Buemi 23 1m 44.167s
2 Sébastien Buemi 28 1m 44.825s
3 Anthony Davidson 28 1m 44.236s
4 Anthony Davidson 28 1m 44.158s
5 Kazuki Nakajima 28 1m 44.240s
6 Kazuki Nakajima 28 1m 44.359s
7 Sébastien Buemi 26 1m 43.857s
8 Sébastien Buemi 12 1m 44.001s

I will leave it to you to draw your own conclusions - compare the lap times of your favourite drivers and see how they did. Certainly no-one disgraced themselves, but the differences are considerably more than 0.02s per lap. The fastest stint in the race, though, was not done by any of the drivers shown above; in fact it was by Oliver Jarvis, in the no. 8 Audi. In his second stint, after the car had lost time in the pits having damage repaired, he put in a 28-lap stint with an average lap time of 1m 43.137s. Earlier in the race, Lucas Di Grassi had also done a (slightly shorter) stint in 1m 43.180s, discounting the effect of the second full course yellow. Only André Lotterer’s first stint (see above, 1m 43.162s) is comparable.

It seems too that the track might have been improving towards the end of the race - in any event, it is impressive that all of the top three cars were going faster at the end of the race than they did at the start. Not much sign of wear and tear over six hours - I wonder what will happen over twenty-four?

But first, Spa-Francorchamps. Will the pecking order be maintained? Will the need to score points in the WEC outweigh the desire to test components ahead of Le Mans? Will there be special Le Mans ‘low-downforce’ aero trim in evidence? What will the weather do?

It’s a tantalising prospect...

1 comment:

  1. Nice analysis, but way too long between updates... Le Mans is already history. I keep checking this site, but I am removing it from my favorites. I know there are no "rules" about how often to update a blog, it is entirely your decision. However, assuming you want to build readership, you need to update more regularly. Good luck in the future.