Almost a year after the original concept idea, Audi Sport has started testing the Audi RS Q e-tron. With this innovative electric prototype, Audi will take part in the Dakar rally for the first time in 2022.
The participation is unique: Audi wants to be the first automaker with an electrified powertrain to compete against conventionally powered competitors and is going for overall victory in one of the world’s toughest rallies. “The quattro was a game changer for the World Rally Championship. Audi was the first brand to win the 24 Hours of Le Mans with an electrified powertrain. Now we are ushering in a new era with the Dakar Rally, where we can test and further develop our e-tron technology under extreme conditions,” said Julius Seebach, Managing Director of Audi Sport GmbH and responsible for Audi’s motorsport activities.
The characteristics of the Dakar Rally present the engineers with special challenges. The marathon event lasts two weeks and the daily stages are up to 800 kilometers long. “That’s quite a long distance,” says Andreas Roos, responsible for the Dakar project at Audi Sport. “What we are going to do has never been done before. This is the ultimate test for an electric powertrain.” Because there are simply no charging stations in the desert, Audi has opted for an innovative charging concept. The powerful high-voltage battery of the Audi RS Q e-tron is charged as required while driving by an energy converter with an efficient TFSI engine from the DTM. Because the combustion engine runs in the particularly efficient range of 4,500 to 6,000 rpm, the specific consumption is well below 200 grams per kWh.
The powertrain of the Audi RS Q e-tron is electric. The front and rear axles are both equipped with a so-called motor generator unit (MGU) from the Audi e-tron FE07 Formula E car that Audi has developed for the 2021 season. Only a few minor adjustments were needed to use the MGU in the Dakar Rally. A third MGU serves as a generator to charge the high-voltage battery while driving. In addition, energy is recovered during braking. The battery weighs about 370 kilograms and has a capacity of about 50 kWh.
“The battery is also an in-house development that we realized together with a partner,” says Stefan Dreyer, head of development at Audi Sport for motorsport projects. “As engineers, we basically see development potential in every part. But in terms of the drive system, we have already achieved a system efficiency of more than 97 percent in Formula E. There is not much more room for improvement. But the battery and power management is another case. This is where the greatest development potential lies. What we learn from the challenging Dakar project will be reflected in future production models. As usual, we are also working closely with our colleagues from passenger car development on this project.”
The maximum system power of the electric powertrain is 500 kW. How much of this may be used during the Dakar Rally has yet to be determined by the organisers. The Audi RS Q e-tron only needs one forward gear. The front and rear axles are not mechanically connected, as is common with electric cars. The software developed by Audi takes over the torque distribution between the axles and thus creates a virtual and freely configurable center differential. This has the positive side effect that it can save weight and space that a cardan shaft and a mechanical differential do need.
Externally, the Audi RS Q e-tron differs significantly from conventionally powered Dakar prototypes. “The vehicle looks futuristic and has many design elements typical of Audi,” said Juan Manuel Diaz, Audi Motorsport Design Team Leader. The brand with the four rings is driving the Dakar Rally in collaboration with Q Motorsport. “Audi has always taken new and daring roads in racing, but I think this is one of the most complex cars I’ve ever seen,” said team principal Sven Quandt. “The electric powertrain requires many different systems to communicate with each other. Besides reliability, which is paramount in the Dakar Rally, that will be the biggest challenge in the coming months.” Quandt compares Audi’s Dakar project to the first moon landing: “At the time, the engineers didn’t really know what was coming for them. It’s comparable with us. When we finish the first Dakar event, I think it’s already a success.”
The prototype of the Audi RS Q e-tron drove its first kilometers at the beginning of July. An intensive testing program and the first tests at cross-country rallies are on the agenda until the end of the year. Andreas Roos: “The schedule for this project is extremely full and challenging. Less than twelve months have passed since the project officially started. We had to start development while the regulations for vehicles with alternative propulsion were not even finalized and we were dealing with the Corona pandemic, what the team has achieved so far is unique.”