Audi unveils details of series hybrid Dakar racer

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Audi Sport has started testing its Audi RS Q e-tron, with which it will take on the Dakar Rally in 2022.

Audi will be the first OEM to compete in the event with a series hybrid, and challenge for overall victory. “The quattro was a game-changer for the World Rally Championship. Audi was the first brand to win the Le Mans 24 Hours with an electrified drivetrain. Now, we want to usher in a new era at the Dakar Rally, while testing and further developing our e-tron technology under extreme conditions,” said Julius Seebach, MD of Audi Sport. “Our RS Q e-tron was created on a blank sheet of paper in record time and stands for Vorsprung durch Technik.”

The characteristics of the Dakar Rally present the German marque’s engineers with a variety of challenges. Not least, the marathon event lasts two weeks and the daily stages are up to 800km in length. “That’s a very long distance,” noted Andreas Roos, responsible for the Dakar project at Audi Sport. “What we are trying to do has never been done before. This is the ultimate challenge for an electric drivetrain.”

Because there are no charging opportunities in the desert, Audi has chosen the series hybrid approach with the TFSI engine from its DTM project, mated to an electric drive. As the IC engine is used only as a generator, it can operate in its most efficient range of between 4,500rpm and 6,000 rpm, with a claimed specific fuel consumption well below 200 grams per kWh.

The front and rear axles are both fitted with a motor-generator unit (MGU) from the current Audi e-tron FE07 Formula E car developed by Audi Sport for the 2021 season. Only minor modifications have been made to use the MGU in the Dakar Rally.

A third MGU, of identical design, is part of the energy converter and serves to recharge the high voltage battery while driving. In addition, energy is recuperated during braking. The battery weighs about 370kg and has a capacity of approximately 50kWh.

“The battery is also a proprietary development that we have realized together with a partner,” said Stefan Dreyer, head of development at Audi Sport for motorsport projects. “As engineers, we basically see development potential in every component. But in terms of the drivetrain system, we have already achieved a system efficiency of over 97% in Formula E. There’s not much more room for improvement. The situation is quite different with the battery and energy management. This is where the greatest development potential lies in electromobility in general. What we learn from the extremely challenging Dakar project will flow into future production models. As always, we are also working closely with our colleagues from road car development on this project.”

The maximum system power of the e-drivetrain is 500kW. However, how much of this may be used during the Dakar Rally is still being finalized by the organizers. The car will run only a single forward gear. The front and rear axles are not mechanically connected, and software will handle the torque distribution between the axles creating a virtual and freely configurable center differential, which has the positive side effect of being able to save the weight and space that would have been required by propshafts and a mechanical differential.

The Dakar Rally entry is being run in conjunction with Q Motorsport. “Audi has always chosen new and bold paths in racing, but I think this is one of the most complex cars that I have ever seen,” said team principal Sven Quandt. “The electric drivetrain means that a lot of different systems have to communicate with each other. Besides reliability, which is paramount in the Dakar Rally, that’s our biggest challenge in the coming months.”

Quandt compared Audi’s Dakar project to the first moon landing: “Back then, the engineers didn’t really know what was coming. It’s similar with us. If we finish the first Dakar event, that’s already a success.”

The prototype of the Audi RS Q e-tron had its first rollout in Neuburg at the beginning of July. An intensive test program and the first test entries at cross-country rallies are on the agenda from now until the end of the year.

“This project’s schedule is extremely packed and challenging,” concluded Roos. “Less than 12 months have passed since the project officially started. We had to begin the development while the regulations for alternatively powered vehicles had not even been finalized yet. And all of the development took place during the Corona pandemic. You mustn’t underestimate that either. What the team has achieved so far is unique. The rollout was a very special moment for everyone.”

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Lawrence has been covering engineering subjects – with a focus on motorsport technology – since 2007 and has edited and contributed to a variety of international titles. Currently he is responsible for content across UKI Media & Events' portfolio of websites while also writing for the company's print titles.

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