AMG has been producing racing versions of Mercedes-Benz cars and high performance street machines for over four decades. That tradition continues with Mercedes-Benz SLS AMG GT3, spec version of the new SLS gullwing coupe.
The GT3 has been developed in cooperation between Mercedes-Benz’s AMG division and HWA, a company headed up by one of the founders of AMG (Hans Werner Aufrecht) that oversees the German carmaker’s DTM (German Touring Car) race operations. The new car retains the visual flavor of the road-going SLS AMG but has been extensively reworked in line with the FIA’s latest GT3 regulations.
The GT3 SLS will use the same 6.3-liter V8 as the road car, but the FIA will determine its final output for racing. The aerodynamic enhancements are the big news here, with changes to the bodywork evident all over. The front end features a deep carbon fiber splitter that’s only bested by the large rear wing out back. The hood sports a large cooling event and there are air intakes for brake cooling in the side skirts and cooling vents in the fenders behind the front wheels as well. Other race-spec features include a smooth underbody, rear diffuser, central-locking wheels and fuel filler pipes in the C-pillar.
The fenders have been widened front and rear to accommodate the large racing tires. With a breadth of 78.3 inches, the GT3 bodyshell is a good 2 inches wider than the series production Mercedes-Benz SLS AMG. The new sills feature openings for cooling the rear brakes, with the smooth underbody visible along the underside of the sills. The B-pillar houses the standardized fuel tank adapter for the rapid refueling system. The 31.7 gallon fuel tank is located centrally behind the driver.
Thanks to its low weight, the acceleration figures for the GT3 – 3.7 seconds for the sprint from 0 to 60 mph – are considerably below the already excellent figures for the series production vehicle. Depending on gear ratio, the top speed is more than 186 mph. In contrast to the series production vehicle, the Mercedes-Benz SLS AMG GT3 is equipped with a six-speed racing transmission with sequential shift. Thanks to its compact construction, the race-tested transmission offers considerable packaging benefits – ultimately, the GT3 version has less ground clearance than the series production vehicle. The driver shifts gear using two shift paddles on the steering wheel. The transmission is mounted directly on the rear axle and connected to the V8 engine via a torque tube, which has a very high degree of flexural and torsional stiffness.
Shortest stopping distances, highest stability and optimal control are guaranteed by the AMG race braking system. All four corners feature brake discs in motorsport-tested composite technology. Gray cast iron axial and radial floating discs are fixed to an aluminum hat via stainless steel composite elements. This sophisticated technology enables perfect heat dissipation and thus reliable stability. The Mercedes-Benz SLS AMG GT3 is also equipped with precisely calculated cooling channels – openings in the front skirt and ahead of the rear wheels direct cool airflow over the brake discs.
On opening the gullwing doors, the Mercedes-Benz SLS AMG GT3 displays a functional interior with a distinctly race car feel. The driver sits in a racing bucket seat fitted with a six-point harness and the HANS system (Head and Neck Support) that fixes the helmet in place in the event of an accident, thus minimizing the risk of injury. Additional safety comes courtesy of the steel roll cage, which also serves to further stiffen the aluminum spaceframe. A steering wheel with a diameter of 13 inches facilitates perfect vehicle control.
Sales will start this fall and AMG hopes to have the homologation process completed in time for the 2011 race season.