Audi is leaving nothing to chance, especially safety, as it prepares for its first Dakar Rally start in Saudi Arabia.
As its RS Q e-tron rally cars are assembled at Audi’s competition headquarters in Germany, desert duellers are teeming with technologies already proven in Le Mans sports cars, DTM touring cars, racing programs. rallycross and Formula E.
The three RS Q e-tron will be driven by Dakar veterans Stéphane Peterhansel and Carlos Sainz, as well as racing and rally star Mattias Ekstrom.
The tests are already well advanced, both on the red sand dunes and rocky desert tracks in Morocco and on dedicated test tracks in Europe.
“Today, four-ring electromobility is no longer a dream of the future, but the present,” says Markus Duesmann, President of Audi.
“We want to continue to show the Vorsprung durch Tecknik brand slogan in high-level international motorsport in the future and develop innovative technologies for our road cars.
“This is why we are taking a new step in electrified motorsport by facing the most extreme conditions. The many technical freedoms offered by the Dakar Rally offer us a perfect test laboratory in this regard.
The RS Q e-tron uses an electric transmission with an efficient combustion engine TFSI extracted from its DTM racers, but operating as part of an energy converter that charges the high-voltage battery while driving. The battery, which weighs around 370 kilograms and has a capacity of 50 kilowatt hours, powers slightly modified generator sets taken from Audi’s latest Formula E car on the front and rear axles.
A third motor-generator set is used as part of the energy converter and recharges the high-voltage battery while driving and also recovers braking energy.
The Dakar dueller has only one forward gear and the front and rear axles are not mechanically linked, as is also common in electric vehicles. Audi software manages the distribution of torque between the axles.
Measuring 4.5 meters long, 2.3 meters wide and measuring 1.95 meters high, the 2000 kilogram RS Q e-tron has a maximum system output power of 500 kilowatts and reaches 100 km / h in only 4.5 seconds on loose gravel, with a roof speed regulated of 170km / h.
All-new raid racers start their lives with a basic tubular steel frame, but there is massive protection for the crew and the high-voltage battery pack, as Audi uses the best technology it can find for the. first hybrid-electric desert racer to face the Dakar.
“The risks in off-road racing were at the heart of the considerations for a sophisticated safety concept. From the electrical safety of the high-voltage system to the optimal protection of passengers in the event of an accident, the design office has taken up many challenges, ”explains Audi.
Although Dakar rules prescribe a steel frame chassis, Audi has turned to the aerospace industry to find a heat resistant, quench and tempered steel that contains chromium, molybendum and vanadium. .
The story is similar through every element of the car, including the protection of the crew from the high voltage elements of the transmission.
“The structural design of the frame incorporates methods and discoveries that we have refined over decades in many disciplines,” says Axel Löffler, the car’s chief designer.
These include the tubular chassis designs of the DTM (2004 to 2011) as well as the sheet steel chassis in rallycross (2017 to 2018) and CFRP monohulls in LMP sports cars (1999 to 2016), in the DTM touring car (2012 to 2020) and single-seaters in Formula E (2017 to 2021).
Depending on the components, the body is made of CFRP, Kevlar or composite, supplemented in some cases by an internal honeycomb structure.
To protect against scratches, a heated and laminated glass windshield from the Audi A4 road car is used, while the side windows are made of lighter polycarbonate.
The cockpit is completely dust-proof and the crew moves around in CFRP hulls, similar in design to DTM and LMP cars. All the seat shells are identical, but the foam inlays and airbags are tailored to each driver and navigator.
The high voltage system of the electric drive, with its energy converter, requires multiple protection. The centrally located high voltage battery is protected by CFRP structures, some reinforced with Zylon.
The lower protection is very complex to protect against the effects of one meter high jumps, swirling stones and large ramp angles.
It starts with an aluminum plate to resist abrasion and partially absorb impact energy, topped with energy-absorbing foam that distributes the loads over a superior sandwich structure above it.
This third structure protects the high voltage battery and the fuel tank.
In total, the structure is 54 millimeters thick.
“With these designs we are seeing a direct transfer of our knowledge from the circuit to off-road rallying,” Löffler explains.
“Certainly the energies are higher off-road due to the long travel of the suspensions, the duration of the load and the mass of the vehicle, but the measured g-forces are similar to those of the Le Mans prototypes.”
But wait, there is more.
An in-car ISO monitor, also used in Le Mans and Formula E diesel hybrids, detects dangerous fault currents. In the event of maximum kinetic loads, such as a collision, the system switches off automatically. In this case, lights on the body and an acoustic signal serve as warnings of danger to the outside world.
Optimal insulation of the system against water during river crossings and an electrically insulating extinguishing agent in the on-board fire extinguisher are also used.