The Audi RS Q e-Tron won its first desert rally in Abu Dhabi, and now the next evolution is ready. The innovative prototype presents itself significantly improved for the 2022 Morocco Rally and the 2023 Dakar Rally. The body is new and features enhanced aerodynamics, lower weight and centre of gravity.
New operating strategies improve the efficiency of the electric drivetrain. The driver and co-driver benefit from more effortless operation in the interior and when changing wheels. Following these evolutions, the RS Q e-Tron now bears the abbreviation E2.
‘We’ve managed a good debut at the Dakar with the Audi RS Q e-Tron and our first stage victories in a motorsport discipline that is new to us,’ says Rolf Michl, Managing Director of Audi Sport GmbH and responsible for motorsport at Audi. ‘The entire team is working together and pulling in the same direction. As is usual at such an early stage, the drivers, co-drivers, and technicians quickly agreed on the next development targets. We have summarised the result in a new evolution package – the RS Q e-Tron E2.’
The RS Q e-Tron E2 launch marks the beginning of the second phase of the development program. In October 2022, Team Audi Sport will prepare for the 2023 Dakar Rally with the new prototype in Morocco. ‘The Audi RS Q e-Tron E2 does not adopt a single body part from its predecessor,’ says Axel Löffler, Chief Designer of the RS Q e-Tron. ‘We are doing away with the rear hood’s underflow to the B-pillars’ left and right. This solution reduces weight with modified lay-ups and optimised fabric layers of composite material.’
To comply with the prescribed interior dimensions, the cockpit, previously narrowly recessed towards the roof, is now significantly wider. The front and rear hoods have also been redesigned. This is accompanied by the lowering of the vehicle’s centre of gravity. ‘The T1U prototypes have to weigh 2,100 instead of 2,000 kilograms in the future,’ continues Löffler. ‘Given that the first generation of the RS Q e-Tron was overweight, it was still necessary to save several dozen kilograms.’
The aerodynamic concept in the body below the hood is entirely new. Its widest point is at the height of the cockpit, while the body tapers significantly towards the front and rear. Audi has now dispensed with the part of the fenders behind the front wheels and formed a transition to the door. Internally, this structure was called the ‘elephant foot.’ As a result, the designers saved more weight and optimised the airflow.
‘The aerodynamic aspect should not be underestimated in desert rallying,’ says Löffler. The new cockpit dimensions mean that the body has a larger and, therefore, less favourable cross-section. Nevertheless, it was possible to reduce the overall aerodynamic drag by around 15%. This does not change the top speed. It remains limited to 170 km/h in the regulations. ‘The improved air flow further reduces the energy requirements of the electrically powered car,’ says Löffler. ‘We implemented the aerodynamic calculations entirely using computational fluid dynamics.’
Energy management plays a crucial role here. The electric drivetrain of the Audi RS Q e-Tron E2 comprises an energy converter consisting of an internal combustion engine and a generator, as well as a high-voltage battery and two electric motors – one on each axle. The electronic control system of the complex electric drivetrain proved its worth in the first rally events. Challenges only arose in extreme cases. For example, Audi noted short-term power surpluses at the Dakar Rally when the wheels made less contact with the ground while jumping or on uneven terrain.
The FIA rules now intervene at a threshold of 2 kilojoules of excess energy and impose sporting penalties. ‘By comparison, more than one hundred times the amount of energy flows to the motors per second within the permissible limits [compared to the previous generation],’ says Florian Semlinger, development engineer for embedded software, application and test bench. ‘We could have made it easy on ourselves and set our threshold several kilowatts lower, but that would have meant performance disadvantages. Instead, we put a lot of fine-tuning into the power controllers.’ The software now recalculates two individual limits – one for each motor – within milliseconds. As a result, it operates precisely along the permissible limit.
The so-called auxiliary consumers also benefit from optimised control. The servo pump, the air- conditioning cooling pump and the fans have a measurable impact on the energy balance. During the debut season in 2022, the Audi and Q Motorsport rally team gained valuable experience that enables better assessment. The air-conditioning system, for example, works so aggressively that it could cause the coolant to freeze when constantly running at its maximum output. In the future, the system will run in an intermittent mode. This saves energy, yet the interior temperatures only fluctuate slightly, even over longer periods. The operating strategy for the fans and the servo pump has also been optimised. The systems can now be regulated differently for the lower load on the liaison stages than on the special ones.
The Audi drivers Mattias Ekström/Emil Bergkvist, Stéphane Peterhansel/Edouard Boulanger and Carlos Sainz/Lucas Cruz can look forward to their new workplaces. The displays are still in the driver’s field of view and located in the centre console in the usual style, and the central switch panel with its 24 fields has also been retained. However, the engineers have restructured the displays and controls.
‘The total of all the functions quickly creates confusion,’ says Florian Selinger. ‘That’s why, for the first time, the driver and co-driver can now select from four system areas using a rotary switch.’ The ‘Stage’ theme contains all the essential functions while driving competitively – such as the speed limiter in sections with speed limits or the air jack. The ‘Road’ part contains, for example, turn signals and the rear-view camera, functions that are often in demand during the liaison stages. The ‘Error’ option detects, categorises, and catalogues errors.
The ‘Settings’ section includes everything useful for the engineering team during testing or after the car arrives at the bivouac, for example, the precise temperatures of individual systems. Crews can now work much more quickly after a puncture. Simple, flat and easily removable body components replace the previous bulky covers for the spare wheels on the flanks. The new ten-spoke rims from partner Rotiform are much easier to handle. Drivers and co-drivers can grip them more easily and safely complete the change.
‘We have combined all the important lessons in a very short time. The result of our ideas is the E2 evolution,’ says Uwe Breuling, Head of Vehicle Operations Audi Sport. ‘Our development team’s determined, and cost-efficient work has prepared us perfectly for our second Dakar Rally.’ Following initial testing led by Arnau Niubó Bosch, Head of Test Engineering, Audi Sport unveiled the RS Q e-Tron E2 in Neuburg an der Donau on September 1, 2022. From October 1-6, 2022, the new technology will have to prove itself in competition for the first time at the Rally du Maroc. All three Audi driver pairings will contest the desert rally that begins and finishes in Agadir, southwest of the North African country.
