Why Audi isn't going radical

Audi looked like a wounded giant at the end of last year's World Endurance Championship. It might have triumphed in the Le Mans 24 Hours and kept the championship open to the penultimate round in Bahrain, but it was outgunned on the Tilkedromes that made up much of the second leg of the series.

Now it is back with a major update of its R18 e-tron quattro and a real confidence that it will be in the fight for the WEC titles as well as a 14th victory in the race that really matters in France on the middle weekend of June.

Audi's reaction to a season in which it was only truly competitive at three of the eight WEC race - the two it won, at Le Mans and Austin, and the season opener at Silverstone - with a root and branch overhaul of the R18. The new shape of the car indicates a major aerodynamic overhaul, while the target of moving up one megajoule class on hybrid power has been achieved.

That means the latest R18 will now run in the division that allows for 4MJ of retrieved energy to be deployed over the long 8.47-mile Circuit de la Sarthe at Le Mans rather than the lowest 2MJ category (and a percentage thereof for the regular tracks).

The failures of the second half of 2014 only provided extra motivation to improve the R18 for the coming season and get back on terms with eventual champion Toyota and ever-improving returnee Porsche, according to Audi Sport boss Wolfgang Ullrich.

"It was a difficult second half of the season but we managed to use that to bring everyone closer together," he says. "There was no finger pointing, no accusing; we just collected everything that we wanted to change for this year and pushed like hell to make it happen. It was push, push, push all winter long. What happened at the end of last year was good motivation."

Evolutionary step

The R18 name remains, but Audi's new WEC challenger has had a big makeover

Audi hasn't built a new car, as Porsche has done, but it's gone for the next best thing. It has undertaken a complete overhaul of the R18 e-tron quattro. So much so that the only carbon components carried over from the new-for-2014 car are the monocoque and the gearbox casing.

"The structural spine of the car is the same, so it is an evolutionary step that builds on the potential of last year; we were able to dig deep into the areas that showed that potential," explains Christopher Reinke, who manages the R18 project in his capacity as technical project leader of LMP1 at Audi Sport.

Reinke points out that last year's R18, the generic name for Audi LMP1 prototypes these days, was Audi's first stab at building a car to the new efficiency-based P1 rulebook. That left room for development, but at the same time a new design was never a possibility for reasons of resource, both financial and technical.

"It was always the plan to continue on the base of the '14 car," says Ullrich.

Hybrid power increase

Audi has achieved its goal of moving into the 4MJ division with a single hybrid system. The latest R18, like its predecessor, retrieves and deploys power only from the front-axle kinetic system, de rigueur for all the manufacturers running in P1 today.

The hybrid system is all new, but, says Reinke, "based on the same concept" as last year, which means one motor-generator and a differential rather than the two front units of the 2012-13 e-tron quattro.

The flywheel energy-storage system has been further developed by the new owner of its manufacturer, Williams Hybrid Power, automotive components company GKN. Reinke says that the "project was taken on in a very professional way by the new owners and the partnership continues as before".

Toyota beat Audi to WEC honours last season, sparking need for a renaissance © XPB

Audi's upgrade of its hybrid systems has been evolutionary in the same way as its approach to the rest of the car, according to Reinke.

"The correct approach was to take it step by step to have a well-sorted 2MJ system for last year and a clear road map very early to upgrade this system in an evolutionary way to this year's 4MJ system," he explains.

"It was the more efficient way to upgrade the existing system to 4MJ rather than introducing a second system."

Reinke said that other hybrid technologies are "constantly under evaluation", but a re-introduction of the turbo-driven system, akin to a Formula 1 Motor Generator Unit-Heat unit, was never on the cards.

Audi originally announced that the 2014 R18 would run an MGU-H before dropping the system because it didn't yield the expected gains and compromised the weight distribution of its turbodiesel contender.

The move to 4MJ means that Audi has more than 200kW of electric boost available through its front wheels. That compares with the ultimate power capacity of 170kW last year.

Three-time Le Mans winner Andre Lotterer, who is again teamed with Benoit Treluyer and Marcel Fassler in 2015, says that the drivers can really feel the difference.

The Ingolstadt marque wants revised car to be added to its list of winners © LAT

"The extra boost is quite noticeable ," says Audi's talisman driver. "We have a bigger boost and boost for longer as well.

"You can really feel the benefit of the four-wheel-drive now, especially at somewhere like Sebring. Out of Turn 17, the rear of the car used to step out over the bumps. Now we don't have to worry: you floor it, the car jumps and off you go. It's pretty cool that our sportscars are doing four-wheel drifts."

Ullrich admits that 4MJ is "the maximum we can do with the current concept". That is as good as confirmation that Audi will abandon the flywheel in future years if it pushes beyond 4MJ. Ullrich is already talking about the use of "road-relevant technologies", which is a clear hint that it will swap to batteries in the same way German rival Porsche has done.

Aerodynamic gains

The all-new aero of the 2015-specification R18 is evident from the photographs of the car undertaking its second test at Sebring earlier this month. The wholesale changes include the nose, which incorporates the front crash structure and has therefore necessitated the car pass a new crash test.

The rear bodywork extends to the full length of car, as on the Le Mans version in previous seasons, as a result of a rule change that mandates that rear impact cones be covered.

The Audi has so far run in the aerodynamic configuration in which it will start the season at Silverstone in April and Spa in May. It's not talking in terms of high- and low-downforce specifications, although it has confirmed there will be a new aero package for Le Mans. Rather, Reinke is promising a different approach to 2015.

"I see us being more flexible than last year," he explains, "but what configuration we will run where isn't decided yet."

Audi believes that a higher-downforce approach - it ran more than its rivals in both sprint and Le Mans-spec last year - is the way to go. Reinke reveals that its simulations maintain that this is correct for what he calls "overall laptime optimisation".

Audi has worked to address a weakness the 2014 car had with getting the most from its tyres © XPB

Suspension changes

The 2014 Audi struggled to unlock performance from its Michelin tyres on occasion last season, most notably at Fuji in October. Audi Sport Team Joest boss Ralf Juttner admits that "we were sometimes weak in getting mechanical grip and getting the tyres in their operating window".

Early testing at Aragon in Spain and at Sebring suggests this issue has been overcome. "We think we've addressed that problem," he adds.

What's happening with the rules?

Nothing, at least until after Le Mans. The Equivalence of Technology between turbodiesel technology and petrol power is set in stone until then, despite Audi's lobbying. Its arguments for a change ahead of next season were rebuffed by the rulemakers and its rivals at a meeting at last season's WEC finale at Interlagos in Brazil.

Can Audi compete at all circuits?

Audi believes the answer is yes, even if Toyota and Porsche move from six to 8MJ with their respective TS040 HYBRID and 919 Hybrid challengers. (Both are due to announce the technical specifications of their 2015 cars the day before the official WEC test at Paul Ricard on March 27/28.)

That would maintain 4MJ gap between them and Audi, but Juttner claims that this means a narrowing of the deficit: "Last year we had 33 per cent of their megajoules and even if they reach eight, it will still mean that we have 50 per cent. Also, we question whether it would be possible to harvest [energy] up to the higher limit at all the tracks across the season."

Audi's focus is still on Le Mans - just as it has been in every season of the prototype adventure that started back in 1999 - when it will run an additional car for Marco Bonanomi, Filipe Albuquerque and Rene Rast, but it believes it can compensate for the lack of hybrid punch where it really tells on the stop-start circuits of the second half of the WEC calendar.

Juttner talks about "challenging" Toyota and Porsche at places such as Fuji, Shanghai and Sakhir, tracks where the R18 was not competitive last year, rather then winning races.

"I believe that we will struggle at some circuits," he explains, "but with the new hybrid system and the steps we have made with the rest of the car, I'm sure we will have reduced the gap, if not completely closed it. We believe we can be within striking distance, which was not the case at some tracks last year."

Reinke echoes Juttner's sentiments, but is perhaps a little more gung-ho about the season.

"I honestly believe - it is more than a hope - that we have addressed the weaknesses of the car and therefore we will be much stronger generally," he says. "We're not going to win every race and I doubt with the competition level we have in WEC that anyone is going to do that.

"Our target is to win the WEC as well as Le Mans. We believe we have the right equipment to achieve that over the full season - and to do that we are not going to have to win every race."