Audi’s DTM program—think the German equivalent of NASCAR—ended at the end of 2020, and 2021 is the German automaker’s final year in Formula E. But the investment that Audi Sport made in both those programs will not go to waste, as aspects of each are combining to power an outrageous-looking machine designed to compete in the Dakar Rally. Unveiled online today, the car is called the Audi RS Q e-tron, and Audi says that campaigning it in one of the world’s toughest off-road races will let the company test and develop its electric powertrains “under extreme conditions.”
Although Audi’s racing exploits have mostly taken place on the confines of race tracks for the last few decades, the brand has a strong link with rallying; it used the World Rally Championship in the 1980s to demonstrate its quattro all-wheel-drive technology. They might both involve rallying, but Dakar is a tougher challenge than the WRC, as it’s contested over two weeks in remote places, with distances of 500 miles (800 km) a day.
“That’s a very long distance,” says Andreas Roos, who is 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.”
The nature of the Dakar ruled out a purely battery-electric approach, although such a thing has been attempted in the past. Instead, Audi Sport has gone for a series hybrid approach—and yes, series hybrid fans, we think this one passes the purity test.
Three Formula E MGUs and a DTM engine walk into a bar…
The tube-framed RS Q e-tron uses a pair of 250 kW (335 hp) electric motor/generator units (MGUs) from Audi Sport’s current Formula E program, one mounted at each axle. These are fed by a 52 kWh (useable) lithium-ion battery pack that may have been borrowed from an Audi e-tron FE07 Formula E car. Total power output is 500 kW (670 hp).
Then there’s a third Formula E MGU, which forms part of the energy converter that charges the battery while the RS Q e-tron is on the move. (The two propulsive MGUs will also regenerate energy under braking.) The other component of the energy converter is a 2.0 L TSFI engine from Audi Sport’s DTM car, which is connected to that third MGU by a shaft. You might not expect a highly strung racing engine to work well as a generator, but Audi Sport says the engine is actually highly efficient when in the right rev range.
“We reduced the output from 450 to about 200 kW. It operates within the narrow optimized rpm range of between 4,500 and 6,000, instead of 9,000 rpm,” said Stefan Dreyer, head of development of motorsport projects at Audi Sport. “The engine has to run as efficiently as possible in the heat, cold, and at altitude. We optimized the pistons, injectors, and turbocharger for this and spent a lot of time on the test bench. We are proud of the specific consumption that is well under 200 grams per kWh.”
“The drivetrain is extremely efficient. There is hardly any power loss. You don’t have to expect temperature problems while you’re driving slowly in the sand. But above all, the electric drivetrain is much easier to control in all of the given situations,” Dreyer said. “The maximum torque is available from zero revolutions. You can regulate the drivetrain very precisely, whether the car is going over jumps or driving in the desert. The electric drivetrain does not react to external influences such as air pressure, temperature, and humidity. And you can use it at full power throughout the rally. It’s all much more consistent than with a combustion engine.”
The RS Q e-tron will also be recharged each night. Although Audi Sport hasn’t shown off the charging solution just yet, it says it plans to use as much clean energy as possible. And the car has been designed to be highly serviceable by a small support team.
The prototype RS Q e-tron first got its feet muddy at the beginning of July, and it’s now undergoing an extensive test program for the remainder of the year, before the 2022 Dakar Rally, which takes place in Saudi Arabia next January.
Audi Sport will enter three RS Q e-trons run by Q Motorsport. One car will be shared by Mattias Ekström (who won DTM and Rallycross championships for Audi) and Emil Bergkvist, one by 14-time Dakar winner Stéphane Peterhansel and Edouard Boulanger, and the third by Carlos Sainz (double WRC champion as well as three-time Dakar winner) and Lucas Cruz.
Listing image by Audi Sport