BMW back to Le Mans

This weekend’s four serious Le Mans 24 Hour contenders are about to be steamed by news that BMW is planning a return in 2018.

While current Le Mans rules favour hybrid cars, it is understood that BMW is working towards its La Sarthe comeback with a pair of radical hydrogen fuel cell racers.

That alone will effectively turn the BMW race program into an electric car assault, running out of the Club de l’Ouest’s experimental Garage 56.

Senior sources at BMW said that while there were still many obstacles in the way, the Le Mans project would be both a technical and promotional leader for its first production fuel-cell car, due in 2020.

“We would have to race out of Garage 56, the way the rules are, but we won’t be going unless we think we can be in the fight to win,” a BMW source said.

BMW hasn’t produced an outright contender for Le Mans since it teamed up with Williams to create the V12 LMR, which won in 1999 with Yannick Dalmas, Jochim Winkelhock and Pierluigi Martini at the wheel. In one of the most competitive Le Mans races in decades, it defeated prototypes from Audi, Mercedes-Benz, Nissan and Toyota – all of which but Benz will fight it out again this year.

BMW board member Klaus Fröhlich was less committal at this week's world premiere of the new 7 Series when asked about his company’s Le Mans future.

“Audi is still racing and winning with this flywheel that spins from Williams. It’s not state-of-the-art, but well refined. All of these systems are highly expensive to develop.

“Never say never for us at Le Mans, but at the moment, for this year, no,” he said.

BMW’s only Le Mans victory came in 1999, when it campaigned the BMW V12 LMR Le Mans prototype built in conjunction with the Williams Formula 1 team.

A BMW comeback would be another feather in the cap of the World Endurance Championship’s innovation-encouraging rule makers, who have seen the WEC and its flagship French prosper as Formula One has stagnated.

Audi, Porsche, Toyota and Nissan are all WEC regulars under the ACO’s hybrid rules, while F1 has Mercedes-Benz, Ferrari and a wobbling Renault. All four run to the WEC’s hybrid-power rules, but in very different ways.

Audi bases its entry around a 700KJ flywheel accumulator derived from Williams’ engineering operation, combined with a 4.0-litre single-turbo diesel V6, and harvests waste energy at four megajoules per lap at Le Mans.

The Porsche 919 uses a turbocharged V4 petrol engine at the back and electric motors to drive the front wheels. It recuperates brake and heat energy at eight megajoules a lap, while Toyota combines a 3.7-litre naturally-aspirated V8, a pair of electric generators and a supercapacitor for ultra-fast charging and discharging speeds.

Nissan’s 2015 entry is the most radical of the 2015 runners, incorporating a front-engined 3.0-litre V6 petrol motor with electric hybrid power and running only front-wheel drive, but it’s none of them are anywhere near as radical as what BMW is planning.

BMW sources are confident that its hydrogen fuel-cell technology, developed in an alliance with Toyota, will be reliable and fast enough to run silently and very quickly at Le Mans.

“The current LMP1 cars are using hybrids and they’re phenomenally expensive to develop as racing cars and represent a step to electric cars. We want to avoid the step and go straight to the electric cars.”

There are plenty of problems to overcome, though, not least of which is the time (and energy) it will take to refuel the high-pressure hydrogen tank (or tanks), which are pressurized to around 700-800 bar, even on road cars.

Then there is weight, because the car will have to also run some kind of battery pack since the fuel cells operate only on-demand and take a fraction of a second to deliver the energy the driver has asked for.

The fuel cells are typically arranged in stacks and work by forcing the hydrogen from the tank (or tanks) and onto an anode, where each atom is broken down into its protons and electrons. The protons work their way through the polymer cell membranes in their haste to reach a positively charged cathode, which is where they react with oxygen (forced into the stack) to create the water vapour that is the only waste product.

With precious little atomic stuff left to do, the lonely, dateless electrons go on to supply electricity, usually at about 95 per cent efficiency and, in current production and near-production cars, at around 0.8 volts per cell.

A fuel-cell LMP1 contender from BMW will demand plenty of complete rethinks from La Sarthe, including its refueling technology, which currently caters for petrol and diesel only.

But it will also require a new alarm system for the pit lane as the BMW prototype will take racing to a whole new level of quiet.

While the ACO didn’t award a reserved entry for an experimental Garage 56 prototype for the 2015 Le Mans 24 Hour, it has plans to keep it open, with James Glickenhaus already said to be keen to use it as early as 2017 for the successor to the SCG003.

“We are looking forward to receiving applications on the condition that they are very interesting projects,” ACO sporting manager Vincent Beaumesnil said.

“The idea is that the car in Garage 56 would showcase technologies that could be used in LMP1 in the future,” he said.

Only two cars have successfully used Garage 56 to actually race in the Le Mans 24 Hour, and both of them have been Nissans. The first was the aerodynamically slippery, lightweight Deltawing in 2012 and the second was last year’s all-electric ZEOD RC, which achieved its target by completing a full lap at racing speed.

A Swiss company called GreenGT entered its hydrogen-powered H2 prototype in 2013, only to withdraw it before the race began, while the ACO backed out of negotiations to invite the series hybrid racer of British tech company Frazer Nash on the grounds that it wasn’t interesting enough.