A Race Engineers' Perspective Following Le Mans Test Day
Rick Mayer, race engineer of the Keating Motorsports/Risi Competizione No. 85 Ferrari 488 GTE-Am team, gives us an updated preview of this year's 24 Hours of Le Mans, June 16-17, 2018, following the recent Le Mans Test.
Drivers Ben Keating, Jeroen Bleekemolen, and Luca Stolz all drove the No. 85 Keating Motorsports/Risi Competizione Ferrari 488 GTE at the recent Le Mans Test and will be the driver line-up for the twice-around-the-clock endurance race.
NOTES FROM THE ENGINEER:
Le Mans is a harsh event to work. Le Mans and I have a love-hate relationship. I look forward to the end of the race each year. You hope Friday isn't a late night for the crew as warm-up is at 9:00 a.m. Saturday and the race starts at 3:00 p.m. You have to get to the track so early on Saturday, it means the crew is working non-stop for just about 40 hours; that is if you finish. It is a constant struggle to pace yourself to maintain concentration and not burn out, especially on Sunday morning and leading into the afternoon. At best you will get a few 10 or 15-minute naps, if you can fit it in and if it works for you. The decision process is a bit complex by Sunday afternoon, maintaining focus is the challenge.
There are some significant differences between GTE-Pro and GTE-Am in the way you approach the event and how the race is run and won. In GTE-Am the only real strategy is in driver rotation; that's not all science as the weather conditions play a significant part in this.
BoP (Balance of Performance) is significant in any class as pace in your class is key to winning, and BoP is a component. In GTE-Pro, the BoP will be more significant as the drivers are all so evenly matched. A big difference between driver lap times in the GTE-Pro class will be .5 seconds per lap. In the GTE-Am class you can only have one 'rated' Pro driver in the 3-driver line-up and one has to be a Bronze, this is meant to be the slowest driver classification. The lap time difference between the fastest and slowest driver is usual 4-10 seconds; a large variation depending on skill level. This difference usually grows at night and in wet or mixed conditions. It's not uncommon at Le Mans for the track to be wet in only portions. Meaning you might be driving with slick tires on a partially wet track or conversely on wets in a partial dry track. In GTE-Am the drivers play the most significant role in the outcome of the race and more specifically the Bronze driver. To win you need to be the best at minimizing the effect of the Bronze driver. The Bronze driver needs to drive when the lap time difference to the Pro is minimized. A simple concept but so many variables make it difficult to get it right.
The past few years the ACO has used slow zones in place of always deploying the safety cars, where drivers maintain speed at 80 kph in sections where track workers are required to remove a car, extract a car from the gravel, repair the track etc. Le Mans has nine (9) slow zones this year with light systems in the cars defining their active locations. This unfortunately adds random time gain or loss to the race. These slow zones are activated at the discretion of the Race Director when required and end when the Race Director is confident the track is clear. This does not coincide with how many times each car runs through the slow zone, it's purely track condition dependent. You could gain or lose 30 seconds or more randomly. Slow zone use has significantly reduced the deployment of the safety cars (3 SCs at Le Mans). Taking care of more minor issues this way keeps the race moving. If you have a fast car without issues this could be to your benefit. If you must repair damage and spend time in the garage this system makes it nearly impossible to gain back laps lost. This is a significant difference in philosophy to the IMSA sanctioned races.
The minimum pit time is regulated by the minimum fueling time (45 seconds in Am), that will drive the total pit stop time so it's very difficult to make up any time in pit strategy; the fueling should always take longer than drivers change and wheel change. The gaps to your competitors must be gained on track.
The minimum drive time for every driver in any class is six hours. All the GTE cars (Pro and Am classes) are ACO mandated to 14 laps a stint max, which is just under an hour a stint. So the slowest driver still has to drive at least six stints if not seven to fulfill the minimum driver time requirement of six hours. That lap time difference between quick Am's and slow Am's now becomes pivotal. The last few Le Mans in GTE were won by the team that spent the least time in the garage; only tires, fuel and drivers change and a brake change about half way through the race. Compounding this you have three dry specifications of Michelin tires to choose from and two wet options. Cars can only use 15 sets of dry tires in the race. Every GTE will be double stinting tires most of the race if it stays dry.
For Risi Competizione and Keating Motorsports our test went well and with a little luck we should be fighting for the win. We're starting from a very positive position having the fastest Bronze GTE-Am driver in the field at the test. Risi Competizione has run well at Le Mans in years past and we are hoping to add to that success.