Tuesday, 19 March 2013

Twelve Hours of Sebring

Subscribers to DailySportsCar.com will have been able to read, earlier this week, my analysis of Audi’s lap times at the Sebring Twelve Hours. As usual, the team will be staying on at Sebring for a further three days' testing – a tremendously useful way to gather information ahead of what promises to be a closely fought season for the World Endurance Championship.

Races these days tend to create a huge amount of data. Having not been at Sebring, I have no particular access to anything private, but there is still a huge amount of information out there, and for teams that gather telemetry information, the trick is not in gathering the information, but in working out how to use it to draw sensible conclusions.

The trouble is that the data never tells the whole story. There are always other parameters; other factors, that influence what is going on, which it is often extremely difficult to get to the bottom of. Things like engine mappings, tyres, driver technique and so on, can have a massive effect on a car’s lap times (or even sector times), and from the outside you can end up tying yourself in a knot, trying to get to the bottom of it all.

With that in mind, there are some observations about the individual driver performances in the Audi Sport Team Joest cars that time did not permit me to investigate in the dailysportscar article, that I thought were worth sharing. As always, I would welcome your comments.

In the winning Audi, number 1, Oliver Jarvis’s fastest lap time was almost 1.9 seconds slower than Benoît Tréluyer’s fastest lap in the same car. The best that Marcel Fässler could manage, having set pole position, was to lap within a second of the flying Frenchman, but he was still 0.8 seconds quicker than Olly.

Taking the average of the fastest 10 laps of each driver shows a similar pattern:
Tréluyer - 1m 45.544s
Fässler - 1m 46.724s
Jarvis - 1m 47.643s

And the average of the fastest 50 laps of each driver is no different either:
Tréluyer - 1m 46.633s
Fässler - 1m 47.857s
Jarvis - 1m 48.852s

Looking at the same information for the number 2 Audi, gives:
Average of fastest 10 laps
Kristensen - 1m 45.681s
McNish - 1m 46.324s
Di Grassi - 1m 47.176s

Average of fastest 50 laps
Kristensen - 1m 46.951s
McNish - 1m 47.391s
Di Grassi - 1m 48.645s

In each case, the order matches the driving order in the car, so the fastest driver started the car, the slowest drove third. Both Audis also copied each other in terms of driving stints, so let’s analyse each stint:

Audi #1
Stint No. Driver Laps Best lap Average of best 10 laps Caution laps
1 Tréluyer 44 1m 45.061s 1m 45.758s None
2 Fässler 49 1m 46.111s 1m 46.937s 5
3 Jarvis 48 1m 46.952s 1m 47.682s 4
4 Tréluyer 78 1m 45.211s 1m 46.098s 5
5 Fässler 65 1m 46.216s 1m 47.183s 6
6 Jarvis 46 1m 47.699s 1m 48.609s None
7 Tréluyer 34 1m 47.121s 1m 48.227s None

Audi #2
Stint No. Driver Laps Best lap Average of best 10 laps Caution laps
1 Kristensen 43 1m 44.870s 1m 45.704s None
2 McNish 62 1m 45.572s 1m 46.399s 5
3 di Grassi 59 1m 46.537s 1m 47.176s 4
4 Kristensen 49 1m 45.956s 1m 46.798s 5
5 McNish 69 1m 46.227s 1m 47.390s 6
6 di Grassi 44 1m 48.356s 1m 49.146s None
7 Kristensen 38 1m 48.024s 1m 48.454s None

All this seems to suggest quite strongly that both di Grassi and Jarvis were significantly slower than their team-mates, which, based on their performances in largely similar cars last year, is surprising to say the least. Maybe it is purely that they were less familiar with both the team and the track?

Also, while I would expect Tréluyer to be quicker than Fässler, I am surprised that Tom Kristensen managed consistently to lap quicker than Allan McNish.

Like I said before, the data doesn’t tell you everything. But if there is an explanation for this, then I’d like to hear it.

1 comment:

  1. I suspect that each drivers threshold of acceptable risk through traffic makes a difference. Who knows, perhaps McNish was minded to treat traffic with relatively more caution on this occasion, as we all know, you have to finish to win!