1999 Mercedes-Benz CLR

Despite winning the FIA GT Championship in dominating fashion for the second year running, the AMG Mercedes-Benz team could not look back at a perfect 1998 season. The big stain on their record was the complete failure of the CLK-LM in the 24 Hours of Le Mans; by far the most important race of the year. After the dominance of Mercedes-Benz in 1998, most of the GT1 class competitors chose not to return to the FIA GT Championship for 1999, leading the FIA to eliminate the category from the series, similar to the DTM/ITC two years earlier.

The Automobile Club de l’Ouest(ACO), organizers of the 24 Hours of Le Mans, chose to follow the FIA’s lead and no longer allow GT1 category cars to enter Le Mans. While FIA GT concentrated solely on their lower GT2 category in 1999, the ACO created a new category of race car known as a Le Mans Grand Touring Prototype (LMGTP).  The LMGTP regulations for closed-cockpit cars were similar to the former GT1 regulations, but shared many elements with the ACO’s existing open-cockpit Le Mans Prototype (LMP) category. This very smart move meant that manufacturers like Toyota, Nissan and Mercedes-Benz all had a reason to return to the great race.  Mercedes, no longer able to compete in the FIA GT Championship with their existing cars, chose to concentrate their efforts on the ACO’s new LMGTP category.

The Mercedes-Benz CLR was a set of racing cars developed for Mercedes-Benz through a collaboration with in-house tuning division Mercedes-AMG and motorsports specialists HWA GmbH. Designed for the Le Mans Grand Touring Prototype (LMGTP) regulations, the CLRs were intended to compete in numerous sports car events during 1999, most notably at the 24 Hours of Le Mans. It was the third in a series of sport cars campaigned by Mercedes, following the CLK GTRs and CLK LMs that had debuted in 1997 and 1998 respectively, and intended as Mercedes’ largest effort to win Le Mans overall for the first time since 1989.

Work on the CLR began in September 1998 as Mercedes was closing out their second FIA GT Championship season. Development of the new car was led by HWA GmbH, which in 1998 was created as a motorsports division of AMG before becoming divested when AMG was merged into Mercedes-Benz’s parent company DaimlerChrysler in 1999. The new LMGTP rule set did not require road legal versions of the cars to be built so Gerhard Ungar, chief designer for HWA, was free to develop a racing car without concern for road legality issues or the inclusion of driver comforts. The transition from GT1 to LMGTP also allowed a decrease in the minimum allowed weight, from 950 kg (2,090 lb) to 900 kg (2,000 lb).

The new design had a much smaller cockpit monocoque made from carbon fiber and aluminium honeycomb. The monocoque design shared its lower half from the CLK LM‘s combination of carbon fiber and steel tube frame, but required a full carbon and aluminum upper half due to new load tests mandatory for LMGTP cockpits. The bodywork of the CLR was also much lower, 10 cm (4 in) shorter in overall height compared to the CLK LM, while the nose was substantially lower and flatter than its predecessor due to a shorter wheelbase allowing longer overhangs. Aerodynamic development on the design was carried out at the University of Stuttgart’s wind tunnel and assisted by the specialists Fondmetal Technologies. Aerodynamic emphasis was placed on low drag for maximum top speed. Mercedes-Benz’s brand image was also retained with the reuse of CLK-Class tail lights from the CLK LM and a front grill and headlights based on the then-new CL-Class.

The powerplant for the CLR was also a variant of the design used on the CLK LM. The GT108C 32 valve V8 engine was loosely based on the M119 engine used in Mercedes-Benz road cars at that time. A previous variant of the M119 had won Le Mans for Mercedes in 1989. Displacement was increased from 5.0 L (310 cu in) to 5.7 L (350 cu in) to compensate for the new air restrictor limitations in the LMGTP category, and allowed the motor to produce approximately 600 bhp (450 kW; 610 PS). The first engine was completed and began testing in December 1998. The Xtrac  6-speed sequential gearbox came directly from the CLK LM, while Bridgestone continued as the team’s tyre supplier. The suspension setup from the CLK LM was largely carried over to the CLR, although a central spring was added to the rear suspension.

Mercedes announced their CLR program to the world in February 1999 just days before the first car began private testing at California Speedway in the United States. Testing continued into March at California as well as Homestead-Miami Speedway in Florida before the team moved to the Circuit de Nevers Magny-Cours in France. At Magny-Cours three CLRs completed a 30 hour test session covering 8,073 mi (12,992 km). On 20 April the CLR was shown to the press for the first time during a test session at the Hockenheimring in Germany. By that point in the development process 21,735 mi (34,979 km) had been covered by CLRs in testing without any major failures.

“We experienced no major problems with the CLR. It ran like clockwork,” stated Mercedes-Benz Motorsport manager Norbert Haug. “We have developed a solid base, which was demonstrated during our last 30-hour test at Magny-Cours last weekend. There we ran more than 3,105 miles with the same car. The team was very pleased with the 8,073 miles covered by the three cars at Magny-Cours.”

The initial schedule for the CLRs consisted of participation in the May pre-qualifying and testing session at Le Mans in preparation for the race in June. At the April debut the team also announced plans to enter several races after Le Mans. The first, scheduled for July, was to be an exhibition event consisting of two 60 mi (97 km) sprint races at the Norisring street circuit in Nuremberg, Germany. Mercedes planned to enter four CLRs in the event. The team would then end their season with the final three races of the American Le Mans Series: the 10-hour Petit Le Mans at Road Atlanta and sprint races at Laguna Seca Raceway and Las Vegas Motor Speedway.

Team AMG Mercedes had three Mercedes CLR sports-prototypes at Le Mans with the following driver teams:

• Jean-Marc Gounon, 36, of France, Marcel Tiemann, 25, of Germany, and Mark Webber, 22, of Australia, drove car number four which utilized the automatic entry
• Christophe Bouchut, 32, of France, Peter Dumbreck, 25, of Great Britain, and Nick Heidfeld, 22, of Germany, drove car number five;
• Bernd Schneider, 35, of Germany, Franck Lagorce, 31, of France, and Pedro Lamy, 27, of Portugal, drove car number six.

Two cars have to be qualified during pre-qualifying May 2, while the number-four car has already been confirmed for the race because Mercedes-Benz won last year’s FIA GT Championship. Of the 34 entered cars in the LMP and LM GTP categories (open and closed sports-prototypes), only 26 will be allowed to race, so eight cars will drop out after pre-qualifying.

With the 1997 and 1998 FIA GT results still fresh, the rival Audi, BMW, Nissan and Toyota teams had every right to be worried. In that light the performance of the CLR at the test-day was quite surprising. Piloted by an all-star crew of drivers, which included the likes of Bernd Schneider, Christophe Bouchut, Nick Heidfeld and Mark Webber, the new Mercedes-Benz could do no better 6th, 14th and 15th. Embarrassed and baffled, the team returned to Stuttgart to try and salvage things before the race.

Come June it only got worse for the AMG-Mercedes team. Bernd Schneider pushed the car to the absolute limits and still only got his CLR up to fourth in qualifying. That was the least of the team’s concerns though. Early in the second day of sessions, CLR No. 4 driven by Webber was following the Audi R8R of Frank Biela through the portion of the circuit connecting Mulsanne Corner and the Indianapolis complex when he moved out of the Audi’s slipstream to prepare a pass. The CLR suddenly lifted its nose and front wheels off the circuit and became airborne, flipping upwards and somersaulting backwards before rotating onto its side. The car impacted the tarmac with its right side while perpendicular to the circuit then flipped back onto its wheels before skidding 300 m (980 ft) into the safety barriers on the side of the circuit. Webber was extracted from the car by track marshals and taken to a nearby hospital suffering from a sore neck, chest, and back. The accident occurred in an area not generally accessible to the public and was not seen by television cameras further up the circuit.

Due to the accident the No. 4 car was unable to improve its qualifying time from the previous day, relegating the car to tenth on the starting grid as competitors improved their times; Mercedes No. 5 also did not improve its lap time and finished the session seventh.
Bernd Schneider was able to go quicker than his time from the previous day with a 3.31.541 lap for the No. 6 car. Toyota took pole position with a 3.29.930 lap, while Schneider’s car was placed fourth on the final starting grid. The wreckage of the No. 4 CLR was returned to Mercedes at the end of the qualifying session and the team issued a press release confirming that they could repair the car before the start of the race two days later. A spare CLR monocoque, taken from their test car, was used to rebuild the No. 4. Webber was able to recover from his injuries by spending the following day in physical training and was cleared on Saturday morning to participate in the race.

On the morning of the race a warm-up session lasting half an hour was held as a final preparation for the teams. The No. 4 Mercedes, repaired after its Thursday accident, joined its two teammates on the circuit as the session began. Webber was once again driving the No. 4 car as the trio made their way down the Mulsanne Straight. Approaching Mulsanne Corner Webber trailed his two teammates but was approximately 15 m (50 ft) behind a Chrysler Viper GTS-R entered by Team Oreca. Cresting a hill at the approach to the corner, Webber’s car lifted its nose into the air once again and rose to nearly 9.1 m (30 ft) above the track, somersaulting backwards before twisting towards its right and impacting the tarmac with the right rear of the car while inverted, shedding its engine cover, rear wing, and nose. The car skidded on its roof into a run-off area just short of the roundabout next to the Mulsanne Corner before coming to a halt. The CLR was swarmed by marshals who were eventually able to right the Mercedes and extract Webber, who sustained no major injuries. Television cameras located at Mulsannes Corner captured the aftermath of the accident and broadcast pictures of the CLR on its roof to the worldwide audience. Photographers in the same location also captured the car as it flipped. The ACO later published these photographs in their 1999 yearbook.

Some of the pictures are HERE and the video is here:

Mercedes immediately withdrew CLR No. 4 from the event as the race was only a few hours from beginning. Norbert Haug, head of Mercedes-Benz’s motorsport activities, contacted Adrian Newey, chief aerodynamicist of the McLaren Formula One team, for consultation on modifying the remaining CLRs to prevent further accidents. The drivers were also consulted on whether they believed the cars were too dangerous to race. Backed by their drivers, Mercedes opted to make modifications to the front bodywork of the two remaining cars by adding dive planes to the fenders for increased downforce and a sacrifice of overall top speed.The drivers were also instructed to not follow other cars too closely.

With only two CLRs remaining, Mercedes took the race start from their fourth and seventh place grid positions. Schneider was able to move into third place behind the two Toyotas in the opening laps while Bouchut followed in fourth. As the Toyotas made their first pit stops, Schneider took over second place before making his first pit stop and relinquishing the position to the pair of BMWs. The No. 1 Toyota eventually suffered transmission issues which dropped it down the order, leaving the top six positions to be swapped amongst the two remaining Toyotas, two Mercedes, and two BMWs as they made pit stops on different schedules. Driver changes during later pit stops had Lagorce getting in the No. 6 to replace Schneider, while Dumbreck replaced Bouchut in the No. 5. Schneider reported that, despite some problems dealing with the car’s new aerodynamics in the beginning of the race, they had been dealt with by the end of his stint and that the CLR was running well.

Towards the close of the fourth hour of the race, Dumbreck’s Mercedes had contact with the GTS-class Porsche 911 GT2 of the Estoril Racing team at the Ford Chicanes, but continued on unhindered. On the 76th lap of the race, Dumbreck was in third place and catching the No. 2 Toyota of Thierry Boutsen in second place. The Mercedes and Toyota were nose to tail on the run from Mulsannes Corner to Indianapolis at nearly 200 mph (320 km/h) with both drivers partially blinded by the setting sun ahead of them. At a slight right kink in the straight, Dumbreck’s CLR ran over the small apex kerbing and suddenly lifted its front wheels from the ground before somersaulting backwards as the entire car became airborne. The Mercedes rotated three times as it flew in the air, reaching a height of nearly 15 m (50 ft). The car continued its trajectory as the circuit curved to the right, clearing a marshals post and the safety barrier on the left side of the track and missing a large advertising billboard bridging the track just ahead of it. Television cameras broadcasting the live world feed captured the CLR’s aerobatics before it went out of view behind trees.

The car impacted the ground in an area of woods alongside the circuit that had been cut and cleared only two weeks prior and was inaccessible to spectators. The car dug a rut in the dirt as it continued to tumble in the clearing. The impact forced a tree limb to penetrate the monocoque between the driver’s seat and fuel tank. The CLR came to rest right side up and track marshals rushed to the stopped car. Track officials quickly slowed the race with caution flags and safety cars in order to dispatch recovery vehicles. Dumbreck was knocked unconscious after the initial impact but awoke and climbed from the car where he was found by the marshals and local Gendarmerie officers in the area. Dumbreck was later given a breathalyser test by the officers due to Le Mans’ use of public roads before being transported by ambulance to a local hospital for examinations before being released. At the end of the 76th lap Lagorce was ordered by the team to bring the remaining CLR directly to its garage; upon the car’s arrival AMG-Mercedes shut the last of their three garage doors signifying their official retirement from the event. National rivals BMW went on to win the race the following day.

Following the race the ACO and the Fédération Française du Sport Automobile (FFSA) national motorsport body investigated the incidents. The FFSA questioned the ACO’s decision to allow Mercedes to continue to compete after the two accidents prior to the race start, but the ACO argued that there were no indications that the problems that befell the No. 4 CLR were shared by the other Mercedes entries. The ACO argued that the design of the CLR, with the longest front and rear overhang amongst the prototype field, was the cause of the problem. A Porsche 911 GT1, similar in design to the CLR, suffered a nearly identical accident the year before at Road Atlanta in the United States. The ACO changed the regulations for the LMGTP category in 2000, decreasing the allowable length of overhang. The FIA also instructed its Advisory Expert Group to develop new regulations to prevent similar airborne accidents in other racing cars. The LMGTP class itself was abandoned by the teams in 2000 as Toyota cancelled their program and Audi concentrated on open-cockpit LMP cars; the class reappeared in 2001.

Peter Dumbreck, in response to his accident, initially blamed the height of the kerbs he had run on when his car became airborne, but Mercedes-Benz responded by stating that blame did not lay with the circuit. The kerbs, as well as the entire Le Mans circuit, were all approved by the FIA. After the 2000 race the ACO and the French government did make modifications to the Route nationale 138 which forms the Mulsanne Straight by decreasing the height of a hill by 7.9 m (26 ft) on the approach to the Mulsanne Corner where Webber had his warm-up accident.

Mercedes-Benz immediately addressed criticism from other drivers and teams of their decisions before the race had concluded. Haug believed that the team’s data from Webber’s practice incident had been adequately analyzed and that none of their drivers felt there were problems with their cars in traffic, prompting his decision to continue. He also stated his belief that contact between the No. 5 CLR and the Estoril Porsche may have damaged the front diffuser and led to the aerodynamic instabilities. Shortly after Le Mans Mercedes conducted their own examination of the accidents by running their remaining CLR on an airfield to verify wind tunnel data. Although no conclusion was made by Mercedes the company canceled the rest of their 1999 program, withdrawing from the Norisring exhibition event and the final three rounds of the American Le Mans Series. The team’s change in plans at the Norisring eventually led to the entire event being cancelled due to a lack of manufacturer participants. Mercedes returned to touring car racing from 2000 onward, and has not participated at Le Mans in any capacity since 1999.

Following the damage to three CLRs during the Le Mans week, the remaining car has rarely been seen, but has begun to make reappearances in recent years.

Chassis: 701Y000003

Chassis ‘003’ was one of the three CLRs entered for the 24 Hours of Le Mans race. In the hands of Schneider, it was the fastest of the trio both in the official test and during qualifying. More importantly, it is the only of the four CLRs that managed to keep all fours on the road. A lap after Dumbreck had his horrendous accident; it was withdrawn from the race. For a long time it was believed that all CLRs were scrapped in attempt to forget the nasty episode. At the 2009 Modena Trackdays this proved to be a wrong assumption as chassis 003 appeared and even more surprisingly, in private ownership. The very brave owner is seen here in action in the only known surviving CLR at the Nürburgring.

Another car is at H.W.A. facility next to AMG center in Affalterbach, Germany: