How a top GT outfit is engineering a virtual Le Mans racer

"When you are doing a real [24-hour] race, you have your tyre man asking you for pressure. You have your team manager asking you how you go, you have interactions with lots of people. You have the noise of the cars and you have to be awake to ask the driver to jump in the car. Here we will be basically in a room with computers, no noise, so it will be really difficult to keep focused for 24 hours without this adrenaline."

As the clock ticks past 3pm French time on Saturday and the Virtual 24 Hours of Le Mans gets underway, there will be many elements that for the competitors will differ from the real-life race, which has been postponed to September amid the COVID-19 pandemic.

But even more so than for the drivers swapping a real-life cockpit for their home simulators, the engineers usually camped on the pitwall with ear-splitting Porsches wailing past every three and a half minutes will feel removed from the action, with none of the same urgency that comes from making race-deciding decisions trackside.

As technical director for Belgian GT and DTM squad WRT, Sebastien Viger will be calling the shots for the team's entry in the Prototype class with pro drivers Kelvin Van der Linde and Dries Vanthoor joined by sim racers Arne Schoonvliet and Fabrice Cornelis.

But nothing can compare to reality, so together with race engineer Wim Everaerts and data engineer Victor Famin - whose father Bruno was previously technical director of Peugeot's 908 LMP1 programme that won the 24 Hours in 2009 - Viger (below) is planning to base himself at the Zolder circuit to replicate the atmosphere of working at a live race track.

"It will be really important to avoid mistakes because apart from some avid sim racers, nobody really knows how tired or how physically engaging this 24 hours will be," says Viger. "You have to stay concentrated with no noise, without a direct view of what the pitlane is going to be for example, so the fresher minds in the last two hours will be quite important strategy-wise and also avoiding mistakes.

"In the preparation race we saw at the start, the first lap was a disaster, everybody crashing into each other, so actually that could be quite decisive in the last two hours. For sure the level of the driver will be important, but we expect it will be really about who can avoid mistakes, who can avoid silly situations and take it seriously."

Before joining the two-time Spa 24 hour-winning squad in 2017, Viger spent the majority of his career working in GP2/Formula 2 for the Spanish-based Racing Engineering squad, running Swiss driver Fabio Leimer to the 2013 title. He spent the latter two years as technical director, and became very familiar with the team's in-house simulator that ran the same r-Factor platform as will be used this weekend.

"So I have some roots of programming and understanding how these models work in sim racing," says Viger, who will engineer F3-convert Fabio Scherer in the WRT's expanded DTM line-up this year.

"It evolved in the last few weeks from pure expectation of only strategy to actually including some [set-up] techniques in the mix" Sebastien Viger

"Obviously this was used as a tool and not used as a race like we see now, [simulation] is just getting bigger and bigger, it evolved quite a lot and we had to adapt quite quickly. The main thing that we realised early on is maybe you have a bit less of engineering to do compared to some real races, but you also have to keep much more focused."

Nevertheless, with the 30-strong field of prototypes each theoretically capable of the same lap-times - all will be using the same Oreca 07 LMP2 model - a good engineering support system can have a profound impact. Viger admits the team's first assumption that the race would be determined more by strategy than by car set-up - due to the limitations of the virtual model - have gradually been altered as its preparations intensified.

"I would say our first assumption was this one, we started everyone like the real world jumping into the sim racer world really relying on the sim racers feedback, how to deal with the game, what are the tricks for the driving," he says. "But soon we realised that, 'okay, the car has a bit of oversteer or understeer, let's try this trick from real-life and actually it kind of worked.

"You still need to understand the model, it's different from the racecar, but the physics principles are still the same and from then on the car got better and better.

"It's kind of transformed a bit in the real-world interaction with the drivers, trying set-ups, trying double stints, trying to save some fuel, when to coast and not. All in all, you need to understand how the virtual car is doing but still have some real-life parameters you can still improve and do like real. It's funny how it evolved in the last few weeks from pure expectation of only strategy to actually including some [set-up] techniques in the mix."

By the same token, Viger says teams have access to even more data than they would in real-life due to restrictions on where they can put sensors.

"You get data like tyre temperature which is quite difficult to get in real-life because of the regulations," he says. "You don't work with the same sensors, especially as some real ones are not present, so I would say you miss some sensors but you have more information from other parts so you can still quite rely on the data you get. You have to work a little differently, but you can still get quite a lot of information. It's quite interesting actually."

The endurance racing pedigree of WRT's lead drivers Vanthoor, a winner of the GTE-Am class at Le Mans in 2017 (below) and 2017 Nurburgring 24 winner van der Linde, who Viger rates as "one of the best of the real drivers in the world at the minute with Max Verstappen", meant their selection "was quite an easy choice". Together with sim aces Cornelis and Schoonvliet, three-quarters of the line-up hail from Belgium, an important distinction for a proud Belgian team.

"I think we have a good line-up, we are lucky enough that our pro drivers and our sim racers are really close together," says Viger. "So for us it will be more about making sure they get some rest and they are fit and they can drive well-rested."

However, not all teams will have a similar luxury, which could create some strategy headaches for teams.

"We're used to having a clear demarcation between pro and am, you know when your pro is in you'll be one second quicker than the am," continues Viger. "Here you have some sim racers who are slower than some pro drivers, but you have some pro drivers that are really slow compared to some sim racers.

"Also you have unknown names: normally as a race engineer you know all the drivers and you know what kind of weakness they can have, but if you have an English sim racer or New Zealand or Polish, you don't really know them. It's quite difficult to tell your driver if the one that's in front is quicker or to expect some erratic driving, so it will be quite tough from this area.

"This is probably the biggest sim event of the last 10 years or probably ever, so it will be interesting, a really tough competition."

"You can call it real racing or virtual racing, but at the end of the day the definition of racing is you have several actors trying to be first and this is what we want to do" Sebastien Viger

For all its experience of winning races and championships in the GT3 arena, WRT's only experience of ACO-sanctioned competition came in a European Le Mans Series race at Spa in 2016, when Vanthoor and elder brother Laurens finished second in a Ligier - despite a qualifying shunt requiring an overnight change of chassis. Viger says the team's inexperience at Le Mans - although team boss Vincent Vosse has five starts, the most recent in 2007 - counts as a "big motivation" to impress against the event's grandee names.

"For a lot of people involved, it's a dream for them," he says. "Victor is quite linked to Le Mans from his family and Wim, and Vincent and I have unfinished business to do Le Mans.

"It's quite a big inspiration to be able to fight on an equal level with guys like Toyota because it can put us on the map of endurance racing as we cannot do at the moment with the [GT3] programme we have.

"For us the model from the beginning was clear enough, this is racing. You can call it real racing or virtual racing, but at the end of the day the definition of racing is you have several actors trying to be first and this is what we want to do.

"We wanted to be serious and this is also what Vincent [Vosse] wanted from the beginning to make sure that the way we work in real-life is transposed to sim racing and we can do it as seriously as a real involvement.

"Hopefully in the future we'll be there with the real car, but at the end it's still a 24-hour Le Mans win that we're going for."