The finishing act of the spectacular 2023 WEC season, 8 Hours of Bahrain, saw the drivers’ champions taking the title in a champion style while their main contender was handicapped on the first corner. We saw the Porsche 963 mixing it well and truly with the Ferrari 499P. The challenge, however, came not from the factory backed Penske team but from car #38 of Hertz team Jota, which has been showing very strong race pace since the 24 Hours of Le Mans. We also saw the two decades old track surface in Bahrain exposing the aerodynamic weaknesses of the otherwise beautiful and daring Peugeot 9X8, demonstrating why its upcoming upgrade is truly needed. We take a closer look at the data from the race, generously provided by FIA WEC and Al Kamel Systems, to try and understand some of the reasons behind the finishing order of the race.

The 8 Hours of Bahrain featured lots of battles for position spread over the entire length of the race, most notably between the Porsches and the Ferraris. This implies a very close race pace which makes it difficult to model the results. On the other hand, the race did not have any interruptions by safety car which makes if simpler to analyse. There were two short full-course-yellow (FCY) periods in the race. FCY periods are designed to preserve the relative order and the gaps between cars and while it does not always work that way their effects on the finishing order tend to be minimal. There were also no post-race penalties in Bahrain which further simplifies our model to two components: race pace and pit time.

The race pace is presented by the median lap time of every car. This is the middle lap after sorting them by lap time. Half of all laps are faster than the median and half are slower. We use the median because it is more robust against outliers. The median is taken after discarding all laps under FCY and all pit-in and pit-out laps. This is shown in the first column of Figure 2. The second column adds to the median race pace the total time spent in the pit divided by the number of laps done by every car. This column should be compared to the right-most column which shows the actual finishing order in the race. The model explains the exact finishing positions of four of the 12 car field. The finishing position of the remaining 8 cars is within one position of the one predicted by the model.

The difference in corrected race pace (race pace plus pit time) between all the cars in the middle of the field, which have their positions miscalculated by the model, is always less than 0.1 second per lap. Exceptions are the second Peugeot- #93 and the Proton Competition Porsche #99. Overall, during the race #93 showed significantly lower pace than the Porsche, 0.471 seconds per lap slower. However, car #99 spent a full minute and a half more in the pit, which reduced the corrected pace difference to 0.133 seconds per lap, still in favor of car #99. Note that car #93 was given a drive-through penalty for speeding under FCY, which cost them another 26.6 seconds in the pit. The decisive factor in the Peugeot finishing ahead of #99 was the last stint driven by Mikkel Nielsen in #93 which was significantly faster than the one done by #99. Car #93 was 11 seconds behind #99 when the latter returned to the track after its last pit stop. Over the following 21 laps to the finish line the Peugeot closed that gap, overtook and pulled another 7 seconds ahead. Because this was just one stint out of the 9 driven by car #93 it is reflected relatively weakly in the median race pace, however, because it was at the very end it proved decisive for the finishing order. One important factor that likely played a role here was the tire compounds used. Sadly, the provided data does not give any information about the tires but in the middle panel of Figure 1 we can see that car #93 shows a steeper and more curved interval profile than car #99, possibly indicating the use of different tires.

During the last hour of the race a curious technical infringement was committed by car #99 for which they were reprimanded, they exceeded the front and total braking torque transfer.

A final note on the race of car #2 – Cadillac Racing. Their race was obviously decided by the first corner lock up, crash into #7 and consecutive penalty. However, while in the qualification they were the third fastest car, during the race, of all hypercars, their median pace was only faster than that of the #4 Vanwall. Which indicates possible damage as a result of the collision.

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