Audi R8 LMS: Lightweight, safe, efficient – the Audi R8 LMS

In 2015, the second generation of the Audi R8 LMS picked up from where its predecessor left off: commercially and racing-wise, the GT3 racing car is a worldwide success. It has been delivered to customers since winter 2015/2016, and by just 2016 Audi had delivered its 200th GT3 sports car.

Even more race car technology, lightweight construction par excellence, more efficient aerodynamics and a standard of safety that surpasses the requirements of racing law: With these qualities, the new Audi R8 LMS picks up from where its successful predecessor left off. Between 2009 and 2016, drivers in both generations of the customer race car have taken 36 drivers’ titles, nine 24-hour races and five 12-hour races worldwide.

Audi Sport GmbH has been building the chassis of the current race car generation in the Böllinger Höfe since September 2015. The final assembly takes place at the Biberach customer racing site. The GT racing car is closely related to the production model – the chassis of both types are built in the same plant.

In terms of safety, Audi plays a pioneering role, as the new Audi R8 LMS clearly surpasses the requirements of the regulations which took effect in 2016. Thanks to a modified structure of the front end and a carbon fiber reinforced plastic (CFRP) crash element being used for the first time at the rear, the GT3 sports car fulfills the crash test requirements for Le Mans prototypes (LMP). The sophisticated Audi Protection Seat PS 3 with its structural stiffness and adaptability to various driver physiques has been setting standards in seating technology for years. It is firmly connected to the chassis, which increases stiffness. An easily adjustable foot lever unit and a height- and length-adjustable safety steering column enable various adjustments to the respective driver. For the first time in a GT3 race car, there is also a rescue hatch in the roof of the kind used in DTM race touring cars. Following a crash, it makes it possible to pull off the driver’s helmet upward in a way that is gentle on the spine and to apply a KED.

Audi has systematically displayed its lightweight design expertise in the new R8 LMS. In spite of the additional weight resulting from the aforementioned innovations, a significant reduction of the race car’s dry weight has been achieved. Now, the homologation weight that has been reduced by 25 kilograms can easily be complied with even in endurance racing trim with additional headlights and air conditioning. The intelligent material mix of aluminum in the Audi Space Frame (ASF), a CFRP structural component, and the steel roll cage make the chassis alone about 30 kilograms lighter – now tipping the scales at 252 kilograms. At the same time, the torsional stiffness of the supporting frame has increased by 39 percent.

Although the race car features a more complex material mix, Audi has interlinked the manufacturing process of the production car and the race even more closely than before. At a manufacturing facility at the Böllinger Höfe industrial park in Heilbronn, Audi Sport GmbH jointly produces both chassis variants. In spite of the race car receiving modified cast-aluminum nodes and a steel roll cage, the racing chassis of the R8 LMS remains integrated in the basis production process up to and including the point of roof assembly and cathodic dip painting (CDP), which is a type of priming. Only after these process steps, the race cars are completed at the Heilbronn-Biberach site.

Engine rebuild after 20,000 kilometers

Audi uses production parts in the new R8 LMS wherever they make technical and economic sense in racing. The V10 engine with 5.2 liters of displacement and up to 430 kW (585 hp) of output in racing is produced on the same assembly line as the production unit. It remains nearly unchanged and, with a scheduled rebuild interval of 20,000 kilometers, sets standards in racing. The designers use modified or completely new assemblies only where they are required by motorsport regulations or by the significantly higher loads encountered in on-track competition. For instance, the production ASF chassis is only modified while the new bodywork consists of CFRP. In the suspensions, wishbones strictly designed for racing have now been installed for the first time. The six-speed transmission with paddle shifters is a completely new development as well. It is 25 kilograms lighter than its predecessor. At the same time, its efficiency has increased because the previously used drop gear arrangement has been eliminated. The new MS 6.4 electronics comprise engine electronics, traction control, and the software for the electrohydraulic gearshift. The powerful processor allows for higher computing speeds and thus faster responses. A power box is another new feature. It replaces the traditional fuse box of the onboard electrical system. As a result, engineers can easily monitor the system loads and protect the system against overload with respect to specific functions.

The new aerodynamics concept of the Audi R8 LMS for the first time includes a fully lined underfloor and a conceptually integrated rear diffusor. As a result, the size of the rear wing profile is reduced by 25 percent compared with the predecessor while the maximum downforce prescribed by the FIA is achieved in spite of the profile’s smaller size. Consequently, aerodynamic drag decreases by 20 percent while top speed, at the same engine output and fuel consumption levels, increases by 6.5 percent. The front wheel wells are open toward the rear via a larger cross-section and thus contribute their share to improved airflow. The airflow rate and cooling surface of the radiator at the front end have increased by ten percent to prepare the car for maximum outside temperatures. The circulation of fresh air in the cockpit has been intensified so that the race drivers can concentrate on their tasks even better than before. At a speed of 200 km/h, the airflow rate amounts to 250 liters per second. Audi has achieved these improvements although the aerodynamic design freedoms provided by the regulations from 2016 on are clearly smaller than before.

As a result, the Audi R8 LMS is featured as an all-round race car for customer racing. It meets the challenges posed on all race tracks in all climatic regions, is capable of delivering high performance, and can be economically operated due to its long service intervals. It offers a maximum level of safety and is equally well suited for sprints and endurance races.