Mercedes-Benz CLK GTR

CLK GTR

Mercedes-Benz CLK-GTR on display

As the Deutsche Tourenwagen Meisterschaft/International Touring Car Championship had folded in late 1996, with both remaining competitors Opel and Alfa Romeo leaving due to the high costs of their 4WD designs, Mercedes-Benz had no top series to compete in. With the success of the BPR Global GT Series leading to the FIA taking over and turning it into an international series known as the FIA GT Championship, Mercedes-Benz saw an opportunity to go against manufacturers like Porsche and Ferrari.

Following the design that Porsche had laid out with their 911 homologation special, the GT1, Mercedes-AMG was tasked by Mercedes-Benz with creating an extreme racing car that still maintained some elements of a normal street legal car. AMG's designers created a car which shared some design elements with the Mercedes-Benz CLK, yet had all the standard features of a racing car underneath. A Mercedes-Benz M120 V12 engine would be at the heart of the car, mounted behind the cockpit. The bodywork would be made entirely of carbon fibre, and would feature many aerodynamic design elements and cooling openings in order to survive on the race track.

To test the CLK GTR before the first chassis were built, Mercedes-AMG actually took an unusual measure. Through secrecy, Mercedes-AMG was able to purchase a disused McLaren F1 GTR, the defending BPR GT series champion, from Larbre Compétition. This purchase first allowed Mercedes-AMG to see the kind of lap times that their competitors could run, to serve as a measurement of the CLK GTR's abilities. However, more importantly, Mercedes-AMG set about modifying this F1 GTR by attaching bodywork that was meant to go on the CLK GTR. Mercedes-Benz also used their own LS600 6.0 liter V12 engine in place of the BMW V12 unit.^[7] This allowed Mercedes-AMG to be able to perfect the aerodynamics of the car before it had even been built.

Upon completion of the first two prototypes a mere 128 days after the initial drawings had been made, the CLK GTRs were entered into the 1997 FIA GT Championship season, debuting at the season-opener at one of Mercedes-Benz's home tracks, the Hockenheimring. Unfortunately the new cars were not able to shine, as brake problems eliminated one car after five laps, and the other finished over 20 laps behind the winning McLaren. However, by the next round at Silverstone, the CLK GTR began to show its pace, finishing less than a second behind the winning McLaren. By the fourth round, returning to Germany for the Nürburgring, a third CLK GTR was added to the team. In this race, Mercedes-Benz successfully outperformed the fleet of McLarens, taking first and second places. The team would finish out the season with five more wins, at A1-Ring, Suzuka, Donington, Sebring, and Laguna Seca, allowing them to secure the team championship as well as the drivers championship for Bernd Schneider.

Mercedes-Benz would use the CLK GTR for the first two rounds of the 1998 season before upgrading to the CLK LM. However privateer team Persson Motorsport would campaign two CLK GTRs throughout the entire season, taking a best finish of second at Oschersleben before finishing the year third in the teams championship.

Initially the CLK-GTR's V12 engine produced approximately 600 hp (450 kW) and 538 lb⋅ft (729 N⋅m) of torque.

CLK LM

Mercedes-Benz CLK LM

After conquering the FIA GT Championship, Mercedes-Benz set its sights on competing at the 24 Hours of Le Mans in 1998, which it had not been at since 1991. However, Le Mans presented a different challenge from that offered in FIA GT, in that the race distances were nearly one tenth the distance covered at Le Mans. Therefore, Mercedes-AMG set about altering the CLK GTR in order to meet the new demands required at Le Mans.

First and foremost, Mercedes-AMG decided that the M120 V12 would not be up to the task of running for 24 hours. Instead, they decided to use the M119 HL V8 engine from Sauber C9/Sauber C11 which raced in the late 1980s and early 1990s, as Mercedes-AMG felt that the M119HL would have better reliability at speeds while still performing the same amount of power as the M120 due to air restrictor regulations. The turbochargers were removed and other revised components were added in order to achieve high rpm.^[8] The modified engine was designated as GT108 B.

Satisfied with the engine, Mercedes-AMG also set about altering the bodywork to better cope with the high speeds of Le Mans. The nose was lowered and the large front brake cooling ducts on the sides of the nose were removed and replaced by a single, large opening in the front of the car. The roof of the car was also lowered and a new engine air intake was designed for better engine cooling along with various other mechanical tweaks. This new car would become known as CLK LM, with the LM designation standing for Le Mans.

Debuting at the 1998 season of Le Mans, the twin CLK LMs entered were immediately quick. The two car team took the pole, ahead of custom built open cockpit Le Mans prototypes. However, Mercedes-AMG's belief of the M119LH engine's reliability and capability was proven wrong as both cars suffered engine failures within the first few hours of the race, leaving Mercedes-Benz dejected.

Returning to FIA GT, Mercedes-Benz replaced their older CLK GTRs with the new CLK LMs and saw greater success. The two cars easily won every remaining race, including six 1-2 finishes. This handed Mercedes-Benz the teams championship again, while Klaus Ludwig and Ricardo Zonta would share the drivers championship.

For the 1999 season, no competitor attempted to enter the GT1 class in FIA GT except for Mercedes-Benz, forcing FIA to cancel the class, similar to the DTM/ITC two years earlier. Mercedes-Benz thus turned to constructing an all-new car to overcome their failure at Le Mans. No longer forced to build a racing car that could also be a road car, Mercedes-AMG set about creating the Mercedes-Benz CLR.

The CLK LM's V8 engine produced approximately 600 hp (608 PS; 447 kW), allowing it to reach speeds up to 330 km/h (205 mph) in testing for the 1998 24 Hours of Le Mans disregarding a claimed virtual top speed of 335 km/h (208 mph). In total, five CLK-LMs were constructed, with one test car for crash testing and subsequently written off, one road-going version was built to comply with the 1998 FIA regulations, and three race versions were constructed. Chassis #005 was sold by Mercedes AMG to a private collector in Japan after the 1998 season and has since changed ownership, but remains in private hands along with the road-going version.^[9]

CLK GTR Roadster

The only right-hand drive Mercedes-Benz CLK GTR Roadster once owned by the Sultan of Brunei

After the completion of the 20 original CLK GTRs, AMG's specialist group H.W.A., who had assisted in the construction of the CLK GTRs, began construction of a roadster version of the CLK GTR. Built either by modifying an existing CLK GTR or by building a new car from spare chassis and parts, these cars were modified with the removal of their roofs as well as a reconstruction of their engine covers. Additionally, the rear wing was replaced by a separate black wing, close to the one on the racing version of the CLK GTR. Further, the Roadster can be recognized by its different front grille, which had a large three-pointed star in it instead of a small version above it. Two rollbars integrating the cockpit headrests were used not only for structural integrity, but also for rollover protection. A total of 6 CLK GTR Roadsters were built by the company. Roadster chassis #1 was the only roadster painted in black and #2 was painted dark silver with a magenta interior. The remaining four were painted silver and have various interior colors.

CLK GTR Super Sport

H.W.A. also constructed a second variant, known as the CLK GTR Super Sport. These cars were similar to CLK GTRs, yet were powered instead by the newer Mercedes-AMG 7.3L V12 which had been in use in the Pagani Zonda and Mercedes-Benz SL73 AMG. Producing 664 PS (488 kW; 655 hp) and 786 N⋅m (580 lb⋅ft) of torque. The car also gained an additional front splitter for better stability at high speeds. Only 5 were built with the 7.3-litre engine: prototype #2, chassis number #01, #03, #13, and #17.