Monday, 26 November 2012

Statistics from the 2012 WEC season - GTE Pro

Last week I posted a summary of the numbers from the LMP1 class of the 2012 World Endurance Championship. This week, I am looking at the GTE Pro class. In many ways, this was a more closely contested class than ever, with a battle between three manufacters throughout the eight races of the championship.

For the sake of simplicity I'm going to limit this analysis to just three cars:
  • the no. 51 AF Corse Ferrari 458 Italia, driven by Gianmaria Bruni (not Bahrain), Giancarlo Fisichella and Toni Vilander (Sebring, Le Mans and Bahrain);
  • the no. 77 Felbermayr Proton Porsche 911 RSR (997), driven by Marc Lieb, Richard Lietz, Patrick Pilet (Sebring) and Wolf Henzler (Le Mans); and
  • the no. 97 AMR Aston Martin Vantage V8, driven by Stefan Mücke, Darren Turner and Adrian Fernandez (Sebring, Le Mans and Silverstone).
The championship certainly boiled down to just these three, and with one or two exceptions (of which more as we go through the detail), they had relatively trouble-free runs throughout the season.

First, I would like look at average lap time - but across a season covering eight different circuits, this makes no sense, so instead, the table below shows the average speed achieved by each of the three when it was on the track (i.e. distance covered divided by time, deducting time spent in the pits).

Car No.51 Ferrari77 Porsche97 Aston Martin
Season Average Speed (excluding pit stops) 172.68 km/h 167.22 km/h 171.04 km/h
Season Average Speed (excluding Le Mans)160.54 km/h 159.94 km/h 157.65 km/h
Potential Season Average Speed (excluding pit stops)180.11 km/h 179.53 km/h178.50 km/h

Readers may recall that the Felbermayr Porsche failed to finish at Le Mans, and since this is by far the fastest circuit (and the longest race) on the calendar, it has something of a disproportionate impact on the results, so I also show what happens if you remove Le Mans from the analysis.

The "Potential Average Speed" is calculated by taking the fastest 50% of laps achieved in each race during the season, and then weighting the average by the length of each individual race.

To summarise, there seems little doubt that the Ferrari is the quickest, on average, although towards the end of the season, the Aston Martin was certainly catching up, but this cannot be seen by merely looking at the season average.

What is not taken into account are the changes that were made to the regulations during the season - e.g. the performance breaks granted to the Porsche from Silverstone onwards, or the reduced fuel tank size for the Ferrari after Bahrain.

Conventional wisdom tells us, however, that average speed on the track is only half the story. The other half of the story is the time spent in the pits. Here are the numbers:

Car 51 Ferrari77 Porsche97 Aston Martin
Average stint on tank of fuel191.1 km 175.6 km 174.2 km
Total time spent in pits5h 14m 23.427s 1h 25m 50.367s 1h 57m 58.353s
Total time spent in pits (Silverstone onwards)47m 19.185s 44m 47.510s 35m 58.280s
Total number of pit stops61 57 66
Total number of pit stops (Silverstone onwards)23 26 25
Average Median Pit Stop Time1m 25.943s 1m 21.105s 1m 24.580s

Due to problems for the Ferrari at Sebring, the Aston at Spa and the aforementioned failure of the Porsche at Le Mans, I have added the numbers for the final five six-hour races for a more realistic comparison. However, even these numbers are unduly affected by longer stops for the Porsche (at Silverstone) and for the Ferrari (at Shanghai).

Perhaps one of the most telling statistics is that the AF Corse Ferrari managed to complete the six hours at Interlagos spending just 5m 36.551s in the pit lane. To show this was no fluke, at Spa its total pit time was 5m 36.613s. Neither the Felbermayr Porsche not the Aston Martin managed to complete a six hour race with less than six minutes in the pits.

The caveats regarding Average Stint Length and the explanation of the Average Median Pit Stop time can be found in my previous post about the LMP1 figures - there is no point in repeating myself here.

What is rather fun, though, is to put the "race parameters" (speed, stint length, pit stop time) into the prediction software and see what comes out. So, if we use an "average circuit", and say that each car has an "average" race, then we get the following results for the "Six Hours of Average":

Car No.51 Ferrari77 Porsche97 Aston Martin
No. of pit stops5 6 6
Projected number of laps161 161 160
Projected Time Taken6h 01m 36.056s6h 02m 36.635s 6h 02m 44.512s

Winners distance: 1,063.96km

Note: The lap length of the "average circuit" is 6.608km and the fastest GTE lap in this "race" was 2m 11.418s, but I'm not sure which driver did it... suggestions welcome!!

1 comment:

  1. Great article Paul - along with the LMP1 version a fantastic insight into the year.

    Thanks Daniel