WEC-HY: 6 Hours of Fuji 2023 analysis
by Boris Deshev, Ph.D.
The 2023 6 Hours of Fuji saw Toyota wrapping up the constructor’s title with a race to go with the local star – Kamui Kobayashi, showing them all how it’s done both in qualifying and the race. We finally saw the Porsche 963 doing what Porsches do best – fighting for victory. At the same time Ferrari had their worse race with the 499P program so far. The race at Fuji was remarkable in one more aspect- more than five and a half hours of racing without safety car (SC) or full-course yellow (FCY) periods. 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 these results.
WEC RACE ANALYSIS TOOL (WRAT)
Figure 1: WEC Race Analysis Tool (WRAT). Top panel shows the position in class. Middle panel shows the gap, in seconds, between the cars and with respect to the average lap time of the winner. Markers on top of the panels show the pit-in laps. Bottom panel shows all lap times with their median shown with the thin horizontal line. Safety Car (SC) and Full-Course Yellow (FCY) periods are indicated in yellow. By default only the podium finishers are shown. Toggle the visibility of the rest by clicking on their entry in the legend.
Figure 1 shows the new WEC Race Analysis Tool (WRAT). It allows the reader to visualise various aspects of the race for all competitors in the class and compare them. The middle panel shows the interval in seconds between every car and an imaginary car doing the average lap time of the winning car on every lap. This ensures that all cars can be compared in the same way. The bottom panel shows the lap times on every race lap, thus showing not only the pace maintained but also the consistency of the delivered lap times. Pit-in and pit-out laps are not shown. The thin line shows the median lap time which is a good proxy of the overall pace maintained during the race and allows a direct comparison.
WHAT DETERMINED THE FINISHING ORDER
Figure 2: Breakdown of the major factors influencing the finishing order in the Hypercar category.
Normally in this section four separate factors are considered and their effect on the finishing order- race pace, pit time, positions lost during SC periods and post-race penalties. Contrary to the pre-race expectations there was no rain during the 6 hours of the race and there were no SC interruptions for the majority of the race. The one SC period right at the beginning of the race had no effect on the finishing order. Similarly, the brief FCY period towards the end also did not play a role. While there were some post-race penalties given they also did not alter the finishing order. This leaves the race pace and pit stop times as the only variables that determined the finishing order. Figure 2 confirms that. The only discrepancy between the finishing order predicted on the basis of race pace plus pit stop time and the actual finishing classification is the #51 Ferrari being ahead of Hertz Team Jota’s #38. The Porsche lost the position due to a drive-through penalty that was handed to them for crashing into their sister LMP2 car #28 an hour and a half into the race. The tiny pace advantage of 0.079 seconds per lap, that #38 had over #51, would have probably been enough to regain that position over 6 hours, but was not enough to do so over the little under four and a half hours remaining after that pit stop. In any case this goes under the uncertainties of the method employed here to explain the finishing order.
DISCUSSION
While this was a relatively simple race to analyse there were few things worth noting.
The pace of Penske Porsche car #6 - faster than #8 Toyota! In total the Porsche spent 13 more seconds in the pit than #8 and finished 8.649 seconds behind. It is not inconceivable that if #5 was in the game as well as #6 was, that could have spoiled #8’s day with consequences for their championship fight.
While all the 963s looked fast at Fuji, the data does not support some of the claims made in the press that #99 Proton Porsche would have likely finished fourth if not held back by a freak seat belt issue in their brand new chassis. As can be seen from the WRAT and Figure 2, both Penske Porsches, the Hertz Team Jota Porsche and the two Ferraris were faster than car #99. In a race where few made strategy mistakes and the perpetual safety car dice did not play a role, pace was the defining factor in the finishing order. On pace alone #99 would have finished eighth their technical problems dropped them to ninth.
The observed drop in performance of the Ferraris compared to Toyota was analysed in detail in another article but one can use the WRAT to see the drop in pace they experienced on the hard tires during the second stint. During the same stint the #2 Cadillac shows exactly the same drop in lap time. While the data on the tires used is not available we can assume they also tried as Ferrari did.
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