The torque tube housing in the 2017 aluminum-bodied Mercedes GT R sports car is made from aviation-grade carbon fiber reinforced plastic (CFRP) in a one-shot production process.
The CFRP tubular shell with heavily loaded connecting flanges that replaces weight-optimized aluminum weighs 30.6 pounds, a 40 percent reduction. It allows a highly direct as well as extremely flexurally resistant and torsionally stiff transaxle-type connection between engine and transmission. The tube and the drive shaft, which is also made of CFRP can easily handle the huge torque of 700 Nm from the 585 hp Mercedes AMG-GT R, according to Mercedes-Benz engineers.
“The torque tube not only absorbs the high forces and torque during vehicle operation, but can also withstand the dynamic load cycles and peak loads that come with a sporty driving style,” the company said.
The component, finalist in the SPE Automotive design competition, was developed by Mercedes AMG with the materials specialists from Daimler Research and the fiber-composite supplier ACE GmbH. The resin is Huntsman 8625 epoxy.
According to the SPE, the part was produced with a new process (first time in auto industry) that is a combination of resin transfer molding and a process from blow molding flexible tubes. The component was inflated in the interior of the tool by vacuum and overpressure. The injection from the resin takes place from the outside.