Gentle in the air, light in the sand: the new body
“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. In order to comply with the prescribed interior dimensions, the cockpit, which was previously narrowly recessed towards the roof, is now significantly wider. The front and rear hoods have also been redesigned. “We are now doing away with the underflow of the rear hood to the left and right of the B-pillars. In conjunction with modified lay-ups, i.e. optimized fabric layers of the composite materials, this solution reduces weight,” says Löffler. The T1U prototypes will have to weigh 2,100 instead of 2,000 kilograms in the future. Given that the first generation of the RS Q e-tron was overweight, it was still necessary to save several dozen kilograms. This is accompanied by the lowering of the vehicle’s center of gravity.
The aerodynamic concept in the area of the body below the hoods is completely new. This section is almost reminiscent of the shape of a boat’s hull: 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 that was behind the front wheels and formed the transition to the door. Internally, this structure was called the “elephant foot.” As a result, the designers saved more weight and optimized the air flow. “The aerodynamic aspect should not be underestimated in desert rallying either,” says Löffler. Admittedly, the new cockpit dimensions mean that the body has a larger and therefore less favorable cross-section. Nevertheless, it was possible to reduce the overall aerodynamic drag by around 15 percent, i.e. the product of the CD value and the frontal area (A). This does not change the top speed. It remains limited to 170 km/h in the regulations. Nevertheless, the improved air flow offers one major advantage. “It further reduces the energy requirements of the electrically powered car,” says Löffler. “We implemented the aerodynamic calculations entirely using computational fluid dynamics (CFD).” These computer simulations replace the time-consuming work in the wind tunnel and still deliver highly precise results.