TG meets the mighty Audi R18 e-tron

UPDATE: Audi has revealed this year's livery at the Circuit de la Sarthe - head this way for all the pictures...  

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This year’s top-flight WEC – and therefore Le Mans – prototype racers are about to enter a season after some of the most extreme regulation changes in endurance racing history. And we’re not joking – if you thought the recent rule changes in F1 were radical, you haven’t seen anything yet.

Essentially, this year’s WEC championship and Le Mans race will not be won by the fastest car. Instead, it’s the team who uses an allotted amount of energy each lap the most efficiently, while covering the most mileage, who will end up on the top step of the podium.

But that’s layman’s terms. You can read the new, very long and incredibly arcane rule book right here to try and get our head round what’s happening. Prepare to leave your brain cells in knots.

So in order to really know what these ruddy complex rules mean for the teams, drivers and cars, this week we went to one of Audi’s secret test sessions in America to let top bods clarify this year’s rules (and comb our brain cells straight again).

Click forth to see the new Audi R18 e-tron quattro in action and find out how the makeup of endurance racing may well have changed forever…

Pictures: Rowan Horncastle

When Le Mans’ legislators – Automobile Club de l'Ouest – planned this year’s rules, there was one over-riding quest: efficiency.

This, you may think, would mean the first thing to go is the wasteful engines. Cut down the cylinders, choke them to death with air-restrictors and make them run on recycled apple juice – that kind of thing. 

But the new rules actually allow engines to run freer than ever: there are no limitations of cylinders, air restrictors have been removed and turbo pressures can now be sky high.

“Awesome! Quad-turbo W16 engines for everyone!” you’d think. You’d be wrong.

Cars now have to drink 30 per cent less fuel than last year. But this isn’t like the fuel restrictions once imposed at Le Mans during the Group C era; a simple case of giving teams a set amount of go-juice and told to run until the tank went dry. Oh no. This is a lot more complicated.

To keep cars efficient, each major team will now be allocated a certain amount of energy per lap based on the size of its mandatory hybrid set-up. This stipulated energy that’s shared by the combustion engine and hybrid system is replenished after each lap, but must not be exceeded. If it is, there are punishments.

Still with us? How it works is that to offset less fuel and smaller fuel tanks, the capacity of a LMP1 car’s batteries or hybrid flywheel system has been massively bumped up to compensate.

In combination with their choice of petrol or diesel engine, a team has to choose a hybrid system that kicks out either two, four, six, or eight megajoules of recovered ‘free’ efficient electric power per lap.

The idea of the given energy allotment per lap (which is still unknown to the teams at this late stage) is about equalizing the hybrid power with the engine power. If you’ve got a big, heavy but powerful 8MJ hybrid, you get less fuel to play with but could be faster. If you have less hybrid oomph from a 2MJ setup, you need to run a smaller, more efficient engine that may not be as powerful and could need to re-fuel more often.

It’s now a strategy game more than ever, and the ACO hasn’t imposed these rules to slow down, decrease power or clip the aero of each car –  just to balance out engine technology and hybrid technology. Something Dr. Wolfgang Ullrich, Head of Audi Motorsport, pointed out:

“In the end we’re all given the same amount of energy and the goal isn’t to make the biggest power out of it, it’s to build the fastest car,” he says.

Essentially LMP1 designers and engineers now have to build a car around a package problem. They know how much energy they can use, so have to mold the fundamental elements of a car – aero, engine, hybrid, drivability and electronic systems that combine the two ­– together into the fastest bundle.

However, the yet-to-be-decided energy allotment (the final number will come out after testing) that drivers have to hit lap after lap will be below the absolute performance potential for each car. Most agree this is a fly in the ointment of ‘true’ pedal-to-the-metal, balls-to-the-wall racing. Instead of getting in a car and just driving it flat out, the modern day endurance racer will have to re-wire his brain.

How? Well, for each lap the driver has to hit their set efficiency target. If they are under the target, they’re just giving away time. It then resets for the next lap. If they go over their target, they have two laps to give the excess energy back. Fail to do that, they get penalized with a stop-go penalty. Which is potential disaster at Le Mans – the 24-hour sprint that’s now won and lost in seconds, not laps.

It all means more pressure on the drivers than ever: anyone behind the wheel is walking a fine line between efficiency and inefficiency. Something Audi’s driver, Oliver Jarvis, isn’t massively keen on.

“The honest answer is that I’m not a huge fan of the rules at the moment,” the Brit driver told us. “As a racing driver you want to be able to go flat out and the rules have changed this. You want to focus on the driving, but now you have other factors that are straining on the mind. That’s before you add traffic.”

Ah yes, traffic. It would be relatively simple to be consistent and fuel efficient if no one else was on the circuit. But having to deal with a flood of slower cars on the circuit is an absolute killer for efficiency, and has forced a change in driving style.

“This year when you see a car 100 metres ahead, your brain has to quickly analyse whether it’s better to stay flat on the throttle and use fuel to pass them,” says Oliver.  “Or, you take the opportunity to lift off, save some fuel, coast into the corner and get them on the exit and use the rest of your energy for the later in the lap. We now have to make those quick calculations every corner, every lap.”

Nine-time Le Mans champ, Tom Kristensen, wandered over to explain exactly how to become a Le Mans hyper-miler. And who better?

 “There are three main ways to be efficient,” says the Great Dane.

“First, you could run a lower fuel mix and engine programme. This means you’re down on power, so you’ll need to be aware in traffic and react differently.

“The second option is to run more power, but coast into corners. With coasting, you have to force your brain to lift off the throttle. But don’t think it’s relaxing. You’re straight on the brakes as hard as you can as you need to get the maximum recovery into the hybrid system to gain what you give away.

“And third, you must be smooth with the throttle and maximize grip, aero and momentum in corners.”

Tom added that these aspects are the absolute opposite of flat-out racing. He’s expecting more pressure as a driver than ever, as he’ll never be able to find a consistent zone or rhythm around the 8.5 mile Le Mans circuit. And this is coming from the most-decorated Le Mans champ in history. We pity the rookies.

TG’s access to Audi’s test session revealed something else interesting. The team has gone back on its initial decision to run the most powerful 8MJ hybrid system, something they initially publicised when launching this wonderfully Sith-looking R18 e-tron quattro.

Strap on for some tech. We were initially told that there’d be a mid-mounted V6 diesel engine powering the rear wheels of the black beast, with a flywheel that would store braking energy from the front axle and reapply it via a motor-generator-unit. They’d also utilise a second hybrid system: the V6’s turbo would be linked to a clever electrical machine that convert the thermal energy of the exhaust gas into electric energy. This energy would also be stored in the flywheel, so whenever the car accelerated the extra power could flow back to the front wheels or to the electric turbo. But not anymore.  

“We have been testing getting energy from exhaust gases as well as the brakes,” Dr Ullrich revealed. “But in the end the risks have been better than the reward.”

Instead, Dr. Ullrich believes that just retrieving energy from the brakes, and using the lowest 2MJ system, is the way forward. Going into a bigger megajoule class – as Porsche will be doing – will add crippling weight which will be difficult to package effectively.

Audi has also changed their diesel V6’s engine capacity to 4.0-litres. That’s more than last year, but is more fuel efficient across the rev range and works in conjunction with the new hybrid system.

What this means is that the three big LMP1 powerhouses – Audi, Porsche and Toyota – will be running three completely different engine configurations. Toyota’s TS040 is sticking with a petrol-powered, naturally aspirated 3.4-litre V8 and 8MJ four-wheel drive hybrid system. Porsche’s 919 has gone for a tiny 2.0-litre turbo-four-cylinder and 8MJ set up. Audi (with good cause, given its recent record), maintains that diesels are the way forward.

Which one will work best with the new hybrid systems? Nobody knows, which will make this year fascinating at the top of the LMP1 class. But Tom Kristensen believes his new car is a strong contender.

“There’s a huge difference in the agility with the new car and the new hybrid system feels much better,” Tom says after testing the car at Sebring the previous week. “This, as well as the combination of the narrow tyre, means you feel more feedback through the steering wheel in slower corners and the whole car is more nimble and very good at coming out corners.”

Will this fight for efficiency, and the fact that drivers can’t just pass when they want, just kill racing as we know it? Dr Ullrich doesn’t think so.

“I’m not concerned at all that we will not see racing,” he says with confident smile. “Don’t worry, there will be fighting because everyone has the same problems. And even if you know at the end of a straight you have to lift, you can be quite sure that the others have to lift as well.”

Oliver Jarvis says the same: “It doesn’t matter If we’ve had to change our driving style or not. As a driver you still want to be on the limit, take chances and deal with traffic. You can’t afford to back off. Ever.”

The one people who won’t know what’s going on are the fans. There are no visual aids, so won’t be able to see which cars are under/over their allotted energy. It may start to look rather odd this year when an LMP1 car isn’t flying past slower cars while they’re trying to save fuel or get back under their energy target.

Still, we don’t think the fans will lose faith. This year sees the renewed fight between Porsche and Audi at the top of the grid.

Now, both are members of the VW Group. What if, say, Porsche and Audi were neck and neck on the last lap? Could Dr. Ullrich get a polite phone call from VW Group CEO Martin Winterkorn requesting help so Porsche could secure the dream return to Le Mans after a 16-year absence?

“I don’t think that’d ever happen,” Ulrich says. “There was a decision in the VW Group that both companies should go racing with different concepts. It doesn’t matter if we’re in the same family. The idea is that there must be some learning factor for these different concepts that’ll be of use to the road cars in the group.”

And fundamentally, that’s why these rules have been made. Unlike F1, which likes to preach about developing technology that’ll trickle down onto your road cars, sports car racing has actually been doing that for decades. In fact, you can thank endurance racing for inventing such mundane items as the windscreen wiper and the disc brake. 

“Road cars that are going to come in the future will have one engine and one hybrid system – exactly like our [race] car,” Dr Ullrich claims.  “So we are on a level that’s very relevant and to get the maximum out of this technology is a challenge and we’ll hand over our results to the guys who make the road cars.”

So while these new rules mean the racing may have changed at Le Mans, it also means that the next R8 will bear far more resemblance to its circuit-based sibling than ever before. And the same goes for all of the other big manufacturers.

Will it work? We have no idea. And the teams are still scratching their heads to make everything work. But this new breed of hyper-hybrid racers go against each other for the first time when the 2014 WEC season kicks off on 20 April at Silverstone. Where hopefully any potential niggles will be ironed out before the ultimate racing season highlight at Le Mans on the weekend of 14-15 June.

Will the Four Rings rule again for a 13th time? Don’t bet against it…