24 Hours of Le Mans: Das über-geek's endurance racing hangover recap

Lead_Photo_Corvette_2
The 24 Hours of Le Mans is over and the day-long knuckle twisting and head-scratching is now just a blurry memory, leaving a dull ache and vague impressions of LMP1 spaceship sounds. If you haven’t heard, Porsche won overall (as I predicted, although I picked the wrong car) for the first time since 1998 and Corvette Racing picked up their eighth victory in the program’s 16 tries at the track (Most race teams would love to bat .500 in big races). But those were only part of the stories, so naturally I did a bit of digging to see how things reached their ultimate conclusions.
Of course I did. My sleep-deprived excitement led me to look at some numbers ahead of the race and I’m also the guy who has examined the irreverent 24 Hours of LeMons under a microscope. So I suppose it’s only natural to
write about how the super-tough French race played out. Anyway, make the jump to dive into the strange depths of my mind, but do check out Daily SportsCar‘s coverage from Le Mans, including their own “By The Numbers” piece.

Before we go into granular detail, it’s worth noting that the constant suggestion that Le Mans is now a 24-hour sprint race is relevant in most regards, but the winners in each of the four classes were the ones that, for the most part, made the fewest mistakes (Interestingly and perhaps not surprisingly, most of the trouble for teams happened in the overnight hours) .There’s obviously a bit more subtlety to it in some cases (hence the rest of this post), but the old maxim of endurance racing still rings true: To finish first, you must first finish.
I’ve summarized the numbers in each class to give a general idea of both how each car ran as a team and how each driver on a team contributed. I tried to compile a reasonable sample size to give an idea of ultimate and/or typical pace. Is my method perfect? Probably not, but I’m also not a mathematician, as much as I’d like to be.
Anyway, I think the analysis still tells some interesting stories, so let’s look at some numbers (Sorry for the Excel screencaps, also, but the chart function here isn’t very friendly to big charts):

LMP1

LMP1_Car
 
LMP1_Driver
I’m not terribly interested in overanalyzing this for a change, so here are a few key things to notice from these two charts:

  • The #19 Porsche’s 4-1/2 extra minutes in the pits over the #17 team car were likely taken under Safety Car conditions when there was no rush to return to the track because of little consequence in losing track position. They instead patiently checked the car over to make sure it would last the duration at its frenetic pace. The #17 had a one-minute drive-through penalty that cost them and the #19’s torrid pace at the same time in the overnight hours (driven by Nick Tandy’s monster stint) may have been the difference-maker.
  • On-track incidents cost the #7, #8, and #18 cars any chances at a win. The #18’s two big issues don’t show on the “Pit Time” because they were off-track excursions that resulted in getting beached in the gravel traps at Mulsanne Corner. This shows in the raw data as very long lap times. The #7 had a tire puncture and some bodywork issues while the #8 was involved in an early wreck going into one of the Slow Zones.
  • As they did last year, Audi ran much faster during the race than they did during qualifying. Unsurprisingly, Andre Lotterer was consistently the fastest in the #7 and Lucas Di Grassi in the #8 matched Lotterer’s pace over the race. Di Grassi and Porsche’s Neal Jani both showed incredible durability by running 161 and 162 laps, respectively.
  • Speaking of impressive drivers, the former/current F1 contingent in Porsche’s cars were night and day. Mark Webber’s ultimate pace was much slower than Nico Hulkenberg’s. Webber was used as #17s’ third driver; Hulk logged the most laps in the #19, although as mentioned above, Tandy’s nighttime stint may have been the drive of the race and Earl Bamber quietly and rapidly went about his business.
  • The #2 Toyota ran a very solid race that probably would have won last year, but they were ultimately short on pace. They gambled that the six Porsche and Audi cars would have issues enough to open the door for them, instead opting to run the whole race to a lap time (in the 3:23-3:24 range, by the averages above). However,I don’t think anyone anticipated all eight cars from those three manufacturers would run more than 97 percent of the total race distance. The one 3:20 lap by the #1 car at least hinted at the TS040’s pace, but by the time they showed that (and it was the only lap under 3:22 for either car), Audi and Porsche had left them far, far behind.
  • Nissan rant: There has been a lot of back-and-forth over Nissan’s teething troubles, but I think their performance was gutsy and perhaps telling. While two cars retired, the #22 finished the race (albeit unclassified for not running 70 percent of race distance). Having a running car at the checkered flag is no small feat at all. They ultimately ran LMP2 pace with a car making half its planned horsepower, a small percentage of its intended braking capacity, and running a question mark of a gearbox. I see two things worth noting in these numbers. First, the more laps a driver put in the car, the better his laps times. This suggests the drivers and probably team were still very much learning about the car under racing conditions even up until the final hour. Second, The GT-R LM ran 12-lap stints using only the internal-combustion engine. I don’t know how many laps a functioning hybrid system will add—indeed that opens a whole Pandora’s Box full of questions not just for the morbidly curious like myself but for Nismo’s engineering team—but it stands to reason they should have no trouble squeezing another lap (if not more) out of a stint next year, when Nismo’s development has hopefully graced the GT-R LM with more pace.

This is me only writing half the things I want to write. On to the next class!
 

LMP2

I’ve only picked out the top five finishers in this cost-capped, pro-amateur class because they tell an unusual story that perhaps flew under the radar.
LMP2_Car
 
LMP2_Driver

  • Most commentators focused on KCMG’s incredible pace and/or Nicolas Lapierre’s massive effort in the car, which were both singularly impressive. What struck me, however, was that the new closed-top Oreca05 consistently ran one lap per stint longer over green-flag runs than their closest class competitors without compromising pace. Why is this important? Because all LMP2 cars have the exact same fuel capacity: 75 liters. It could be the car’s low coefficient of drag (It was fastest through the speed trap all week at 310 kilometers per hour) or it could be any of a dozen other factors from driver coaching to fuel-pump pickup design to, well, the factors are myriad. However it was done, it stands out to me as the most incredible and perhaps unnoticed factor in the whole race weekend.
  • The LMP2 margin of victory was only 48 seconds over the charging JOTA Sport Gibson (nee Zytek). KCMG probably wasn’t pushing late in the race and let that gap narrow in the closing minutes, but with a pit stop costing about a minute each, one could argue that eliminating a pit stop won them the race. The Hong Kong-registered team wasn’t without issue, however: The Oreca stalled on the Mulsanne but was able to restart and they also had to serve a drive-through penalty earlier in the race. Nevertheless, JOTA’s first-hour troubles with a gear-selection issue were enough to keep them from being repeat winners. That said, Kiwi Mitch Evans and Brit Oliver Turvey both turned in heroic performances while Simon Dolan gave them a solid amateur performance in the pro-am class.
  • The G-Drive Ligiers were also hugely impressive. Strategy in the pro-am classes tends to mean using the amateur driver only to the bare minimum and Julian Canal’s pace couldn’t match Dolan or Matt Howson in the cars ahead. Nevertheless, pro Sam Bird—who has had rotten luck all season—put in a heroic effort in the #26, clocking a staggering 171 laps while also churning out an absurd pace.
  • The Murphy Prototypes open-topped Oreca03R is admittedly fairly out of date, but Karun Chandhok said during the race they were just trying to make the car last and bring it home in one piece. They were certainly in the hunt late in the race on the back of a 12-lap fuel strategy before a couple of small problems knocked them back to fifth. Murphy have a proclivity for finding young talent and French protege Nathanael Berthon certainly will have caught the eye of several LMP1 team bosses.
  • Only three of the 19 cars in the class were able consistenly to run 12-lap stints in the class: KCMG, Murphy, and the Signatech Alpine (which is essentially a slightly redesigned Oreca03R) that crashed out overnight but would have otherwise made it interesting.
  • With the way this race unfolded, it’s surely a disappointment that the ACO is changing LMP2 regulations in 2017 to limit chassis in the class to just four manufacturers and a single engine.

 

GTE-PRO

Until the race’s last two hours, this was a heated battle between Corvette Racing and the #51 AF Corse Ferrari.
GTEPRO_Car
 
GTEPRO_Driver
 

  • When I talked to Oliver Gavin a couple weeks ago, he said the goal for Le Mans was simple: (1) Drive the car, (2) bring it in for fuel, (3) go back out and drive the car, (4) then bring it in for fuel, tires, and a new driver. Repeat as necessary. That’s exactly what Corvette Racing did for the duration of the race. Like all GT cars, they had to do a brake change during the race, pitting from the lead of a duel against #51 with about eight hours left to do so. That brake change cost them track position and dropped them to a couple seconds behind the Ferrari and the race was on from there with Tommy Milner battling Toni Vilander in a huge fracas.
  • As I was crunching numbers at that point, I saw that AF Corse probably had the upper hand and would need one fewer pit stop from that point to the race’s end. That turned out to be moot when Ferrari’s ace Giammaria Bruni suffered gear selection issues after taking over the car for the final push. The fix cost them seven laps and any chance at back-to-back victories.
  • Interestingly in the second-place #71 car, veteran GT racer Olivier Beretta lacked pace and was relegated to basically bridging the gap between his younger, faster colleagues Davide Rigon and James Calado. The five-time Le Mans class winner (two in Vipers, three in Corvettes) will probably continue racing at Le Mans for many years, but this may be his last foray in one of AF Corse’s leading PRO-class cars. If that’s the case, it will close a 20-year chapter in Beretta’s storied career of racing in the to GT class at La Sarthe.

 

GTE-AM

Of all the classes, the pro-amateur class here turned into the most intriguing. One car dominated almost the entire race, only to have it undone in the final hour with a crash. Behind them, the race was perhaps a lot closer than it seemed.
 
 
GTEAM_Driver
GTEAM_Car

  • Yes, it was the #98 Aston Martin Racing car that was the class of the field, leading by a full lap before Paul Dalla Lana crashed hard in the Ford Chicane during the race’s final hour. The story leading up to that was fairly incredible: The team’s pro driver, Pedro Lamy, racked up something like 10 hours of driving despite having chicken pox. He managed spectacular pace while Dalla Lana was uncatchable among the bronze drivers in the class (Every team may have a maximum of one pro driver and one silver driver). Mathias Lauda was reasonably quick, but the really impressive bit comes from the fact that the Aston could only go 13 laps on a fuel stint, compared with 14 for every other GTE car. That meant their lead late in the race had come despite the deficit of having one extra visit to pit lane.
  • SMP’s win is in itself fairly incredible. The car suffered through a bit of contact and an off-course run that required a tug out of the gravel trap. Had they not had those setbacks, they very likely would been challenging the Aston Martin for the win through the last hour if the #98 had similarly had no troubles since their driver lineup was very fast, including impressive pace from silver-rated Victor Shaytar. Regardless, they inherited the lead and overcame their troubles by simply outpacing the Dempsey-Proton Porsche.
  • Patrick Dempsey’s team finished on the podium and Dempsey should be profusely thanking his Porsche factory driver coach Patrick Long, who was only seven laps short of literally running half the car’s race distance. The pros in GTE-AM are expected to do the heavy lifting and Long had his fair share of that. Those paychecks are tough to earn for the pros in these classes.
  • All-American team Scuderia Corsa made it five Americans on the class podium in their debut at Le Mans. They got solid performances from Jeff Segal and Townsend Bell while Sweedler acquitted himself nicely as an Am in the team’s first visit to Le Mans.
  • As with Sweedler, Dempsey’s 50-lap average is skewed by the fact that each driver only ran a bit more than 50 laps to reach the four-hour drive-time minimum for amateur drivers. As a result, some caution and Slow Zone laps end up in the calculation. In reality, Dempsey was probably 10 to 15 seconds quicker over a green-flag lap than his average and Sweedler was five to seven seconds quicker.
  • Before the race, I said the #83 AF Corse was Aston Martin’s biggest challenger on paper, but a broken splitter set them back just enough that thy were a non-factor. Francois Perrodo was second only to Paul Dalla Lana in pace for a bronze driver while silver driver Rui Aguas split time almost equally with 1998 Le mans overall winner Emmanuel Collard, who was starting his 21st consecutive race at La Sarthe. Interestingly, this car ran a few 15-lap stints without Safety Car conditions. Even if these occurred during local Slow Zones (basically speed-controlled local cautions), that means they were close enough to making 15 laps under full-green conditions that a couple miles at 80 kilometers per hour stretched it just enough to sputter in on fumes after 15 laps.

 
That’s what I see in the numbers, which is of course only a fraction of the stories that take place over a 24-hour race and in the weeks, months, and years leading up to it. And following it. So starts another year of anticipation for next year’s Le Mans, which we already know will see the return of the Ford GT (at the hands of Chip Ganassi Racing and Multimatic Racing) and a new Toyota LMP1 (the TS050).
Fin.
 
[Lead image source: Richard Prince/Chevy Racing | All other images copyright 2015 Hooniverse/Eric Rood | Information source: FIA WEC Live Timing]

0 Comments

  1. My conservative calculation (tank completely empty at every refill, 100% filled every time):
    (initial filling + 32 pit stops) X 68.5L gas over (395 laps X 13.629km each )
    ->Upper ceiling for fuel consumption is 42L per 100km (5.6MPG).
    That’s a 40ton semi truck going 80kph, or a city bus with hybrid engine doing 25kph on average….
    Does anybody know the tank volumes of the other classes?

    1. They can use even more fuel than that. 395 laps in 24 hours is 16.5 laps per hour. The maximum fuel flow for a 8MJ petrol hybrid is 88.5 kg per hour. 88.5 kg of petrol is just over 120 liters.
      16.5 laps x 13.629 km = 224.87 km to use 120 liters of fuel. That is 53.4L per 100km. So even with 42L per 100km, they are in serious fuel saving mode – 21% less than theoretically allowed.

      1. I didn’t know about the flow restrictions (neither the rest of the rules). I am too lazy to calculate the optimum green flag stint length and fuel flow for a given speed regime, but I guess 13 is a good number: burning 10% more wouldn’t make one 10% faster…

        1. Fuel flow restriction only applies to LMP1, I’m pretty sure. The GT cars’ fuel capacities are part of the balance of performance, so they’re all a bit different.
          Interestingly, I believe the Aston Martins had the largest fuel tank capacity in GTE.

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