WEC-LMGTE: 6 Hours of Monza 2023 report
by Boris Deshev, Ph.D.
The 6 Hours of Monza saw the coronation of Corvette Racing as the 2023 champions, with two rounds remaining. A return to (the top of) the podium for Dempsey – Proton Racing, for the first time since the opening round at Sebring. It also saw a dramatic rise from last to second for the Iron Lynx car and a fall from a dominant pole position to fifth for the Iron Dames car, which we analysed in detail in another article. Here we take a deep dive into the data from the race, kindly provided by FIA WEC and Al Kamel Systems, to find out what were the factors that determined the finishing order of the highly competitive LMGTE class. Meanwhile if you have missed the race you can admire it in its full length on WEC TV and on WEC’s official youtube channel.
RACE DEVELOPMENT
Figure 1. Interactive plot showing the development of the race for the LMGTE class. Position in class (top left) and gap between the cars (bottom left). Yellow areas show safety car (SC) or full course yellow (FCY) periods. The panel on the right shows the distribution of lap times, expressed as a percentage of the fastest in class. The thin vertical lines show the medians of the distributions. Cars are ordered in their finishing order.
Select which traces are displayed by clicking on the legend. Double clicking deselects all other traces. This figure (created with Plotly) will not display properly on screens narrower than 800 pixels
Figure 1 shows the overall development of the race for the LMGTE class. The plot is interactive allowing the reader to toggle the visibility of individual cars by clicking on their entry in the legend or selecting only one car by double clicking on it. The bottom left panel shows the gap between the cars. The absolute vertical offset is in relation to an imaginary car that does the average lap time of the winner on every lap. The relative offset between the cars shows the real gap between them in seconds. The lap time distributions and their medians, shown on the bottom-right panel, exclude the SC/FCY laps as well as the pit-in and pit-out ones. The lap times are expressed as a percentage of the fastest possible lap in the class over the entire weekend and only show laps within 107% of it. The fastest possible lap is the sum of the three fastest sectors from the entire weekend, which are S1 – 34.010 by #33 Corvette, S2 – 36.037 by #56 Porsche and S3 - 36.359 by #77 Porsche, for a combined lap time of 1:46.406. For comparison, the fastest complete lap driven by any LMGTE car during this event was 1:46.762 by #56 of Project 1-AO during the third practice. The first two fastest sectors were achieved during the third practice session and the last during the race. This shows an interesting contrast to the hypercars’ fastest sectors which were all achieved during the qualification. At the same time, car #85’s pole position had a margin over the second-placed car of 0.426 seconds. The margin between the first and the seventh car in the Hypercar class during the qualification was smaller- 0.422 seconds! It seems that the qualification is less important for the LMGTE class than it is for the Hypercar class. Expect an upcoming article on the subject at kineticum.com. The margin between the fastest lap driven and the fastest possible lap is the same for the LMGTE cars and the hypercars – around 0.3 seconds.
The 107% lap time limit, shown on the bottom right panel of Figure 1, equates to 1:53.854. This comfortably included more than 97% of all race laps driven by all LMGTE cars that completed the race. A notable feature of the lap time histograms shown on Figure 1 is the width of the distribution which, for the LMGTE class, mostly shows the difference between the pace maintained by amateur drivers and the rest.
WHAT DETERMINED THE FINISHING ORDER
Figure 2. Factors that determined the finishing order in the LMGTE class. From Left to right every column adds another factor to the previous one. See which column brings the car to its finishing position shown in the last column.
While there are many factors that can affect the outcome of an endurance race, below we consider the effects of three of them plus all post-race penalties. The median race pace is a good measure of the pace maintained during the whole race (explained in more details here). The total pit time is divided by the number of laps completed and added to the median race pace to take into account strategy and any technical problems encountered. The timing of safety car periods have the potential to alter the order of the competitors when combined with pit stops. On Figure 2 we build up the effect of these four factors with every column from left to right. The final positions are shown in the last column.
DISCUSSION
There were four cars in the LMGTE race whose final positions appear to be determined by their median race pace and little else- #77 and #60, which finished first and second, respectively, #83 which finished sixth, and #21 which finished ninth- out of 10 classified cars. This apparent simplicity is, however, illusive. While #77 did have a very strong pace, they were also the only team to execute the race with only five pit stops for a total pit time 23 seconds shorter than the next shortest in class. Car #60 started last and showed relatively poor pace during the first third of the race. A very strong pace in the remaining race more than compensated for that (check their histogram on Figure 1). They did a pit stop right before the second and third (last) SC period which helped them finish in the position determined by their median race pace.
The AF Corse car #21 had a penalty during the race and after it, both for abusing track limits, together with another penalty for leaving a gap behind the SC. The only reason why this did not affect their finishing position is that the only car behind them- #54- had technical problems which resulted in almost five minutes longer total pit time than that of #21. This determined #54’s final position, after a very promising first half of the race when they run consistency near the top.
The Richard Mille AF Corse car #83 had a very strong early two stints before loosing a number of positions due to a double pit stop during the second SC period, which also gave them a time penalty for leaving a gap behind the SC. They recovered one position during the last few laps when #56 was serving a penalty for track limits abuse (for which they were also handed a post-race penalty). This post-race penalty also helped #25 of ORT by TF move to its finishing position. They had the slowest pace of the entire LMGTE pack but were running in the top half of the order before the last SC period when they had to make a double stop from third, which delegated them to their final on-track position- eight, improved to seventh by the above-mentioned penalty for #56.
Overall #56 of Project 1-AO had a messy race which shows in their histogram (double peaked). They did get lucky with the SC periods, stopping just before the last two, loosing no positions. Following two penalties for abusing track limits they could have finished further below the position determined by their pace and strategy.
The real success story of the race at Monza was that of car #86 of GR Racing which , at the same time, was the undoing of the race for cars #33 and #85. Car #86 stopped four laps before the last SC which handed them back any time lost. By the time of their next pit stop, two laps after the end of the SC period, they were in second position. From that moment it was a straight fight between #86, #85 and #33. The last pit stop of #86 was 10 and 12 seconds faster than those of #33 and #85, respectively. This is when #86 gained its finishing position. Ultimately it was a very strong pace plus superior strategy which won them the third place. During their second-to-last pit stop they did likely loose time, as they stopped shortly after the SC period but so did #33 and #85. Irrespective of that #86 would have likely not been able to challenge the second place of the Iron Lynx car due to their lower overall pace.
The new champions managed to gain a position on the Iron Dames car #85 by better pit work. Despite them taking a drive-through penalty for speeding in the pit lane, their total pit time was 7 seconds shorter than that of car #85.
more from kineticu.com
What are the factors that determined the finishing order in the hypercar class at Monza?
The dice that undid all the good work. Lessons from the Iron * race at Monza
(published on 12.July.2023)
The Iron Dames car took pole position with ease and kept the strong pace during the race. Yet it finished fifth in class. We analyse the data from the 6 Hours of Monza, 2023 to understand why.
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