Silver Anniversary
25 years ago, after three decades away from the track, the Silver Arrows came back to claim overall victory in the 1989 24 Hours of Le Mans

Success in auto racing has played a large role in shaping the Mercedes-Benz mystique. For nearly six decades, Mercedes-Benz entries had competed and won on tracks around the world. But then in 1955, after winning the Formula 1 and Sportscar World Championships, Mercedes-Benz retired from motor racing, with no expectation of ever coming back.
As the years passed, the idea of returning became less and less likely because Mercedes-Benz would need to be instantly successful to add to the reputation forged with victories before World War I, in the 1930s and again in the 1950s. But in the mid 1980s, the regulations for the World Sports Prototype Championship (WSPC) were changed to allow any piston engine to compete. The only requirement was that engines must use less than half a liter of fuel for every kilometer of competition.
An independent Swiss chassis constructor named Peter Sauber saw the change in rules as an opportunity to challenge for overall victory. Sauber wrote to executives at Mercedes-Benz and requested use of the company’s wind tunnel in order to refine the aerodynamics of his newest chassis and was surprised to get approval. While at Untertürkheim, Sauber explained the new fuel-efficiency formula to various Mercedes engineers. Dr. Hermann Hiereth, head of engine research, discussed the rules in depth and Sauber mentioned that he thought the 4.5-liter V-8 used in Mercedes production cars (the M117) might be a viable powerplant for the series.
Intrigued, Hiereth directed his staff to mount twin turbochargers to an M117 to see how it performed. The engine easily produced more than 650 brake horsepower, and the small group of technicians started to tinker to refine the torque band, develop a dry-sump oiling system and achieve the fuel economy needed to go racing.
With Sauber regularly requesting the chance to borrow the engine for races, Hiereth produced technical data that convinced the Mercedes-Benz AG board of management that racing would provide real value in increasing the technical performance of the M117. And with the engines in a Sauber chassis and no visible trackside support by Mercedes engineers, the effort could protect the Mercedes image – the cars were the product of a small, industrious Swiss constructor and they would be remembered that way if they lost. If they won, the name Sauber-Mercedes would add to the Mercedes legacy of racing success.
A winless 1985 was followed with improvements in speed and reliability in 1986 and 1987 (with one WSPC victory each year at the Nürburgring). Positive media reports added to the value of more technical knowledge and Mercedes executives made the decision to provide primary team sponsorship – by Daimler subsidiary AEG electronics – and greater technical support at the races.
The Sauber-Mercedes team won five of the 11 races in 1988 to finish second in the WSPC teams championship, but the crown jewel of the series – the 24 Hours of Le Mans – was a massive failure. A tire blew out at top speed in practice and exhaustive analysis could not determine the cause, so the cars were withdrawn.
For 1989, Mercedes wanted the public worldwide to know that it was returning to racing. To make the point clear, the decision was made to paint the Sauber C9 chassis silver with only the Mercedes three-pointed star on the nose, creating a classy connection to the Silver Arrows of old.
Facing six rival manufacturers, Sauber wanted a more powerful engine, so Hiereth and the Mercedes engineering staff decided to modify the new M119 5-liter, 32-valve V-8 used in the 1989 500SL. The M119, using the same block as the M117 but with a head containing twice as many valves, produced more horsepower and more torque than its predecessor. The racing version of the M119 featured a remarkable number of pieces – including the light-alloy engine block, cylinder liners, cylinder heads, valves and camshafts – that were only slight modifications of production parts. Sharing so many pieces with the production engine gave the C9 a strong kinship with the 1952 Le Mans-winning 300SL, a car with a special tube-frame chassis and an engine and transmission picked from the production line.
The C9 was still a thoroughbred. Some special parts – forged Mahle pistons, titanium connecting rods, twin KKK K-27 turbochargers, Bosch Motronic 2.7 sequential fuel injection and an integrated intercooler regulation that controlled both fuel mixture and ignition timing – enabled the racing M119 to produce 730 brake horsepower. The aluminum monocoque chassis utilized a steel roll cage, and flowing Kevlar bodywork created a gorgeously functional race car.
Though a dispute over TV money kept Le Mans out of the 1989 WSPC, Sauber and Mercedes planned a full assault on the legendary endurance race. Using a special car with carbon-fiber brakes and a different chip in the Bosch CPU for qualifying, lead driver Jean-Louis Schlesser became the second driver ever to surpass 250 mph on the Hunaudières straight and earned the pole in No. 62 with a record lap of 3:15.04 around the 8.4-mile circuit. Teammate Mauro Baldi was second in car No. 61, 0.63 of a second behind, but the third C9, No. 63 driven by veteran Jochen Mass, broke its gearbox during its qualification run and posted the 11th best time. The mechanics could find no flaws in design or manufacturing and dismissed the problem as an isolated issue, but nevertheless installed a shorter fifth gear – costing about 5 mph on the long straight – on all three cars just to be safe.
Facing a strong four-car challenge from defending champion Jaguar and a 17-car attack from the aging but reliable Porsche 962, the Sauber-Mercedes trio raced to a set lap time. Though Baldi passed Schlesser as the green flag dropped, Davy Jones grabbed the lead for Jaguar on lap 2. The Silver Arrows fell down the standings over the next 10 laps as the Jaguars and several Porsches chose to race aggressively.
Trouble hit – literally – the No. 63 Sauber-Mercedes an hour and a half into the race. On the second lap after taking over from Mass, Manuel Reuter ran over a broken exhaust pipe from another car. The nose of the C9 was damaged and the pipe smashed a hole in the floor as it dragged along around the track. Stopping for a new nose and repairs, No. 63 dropped to 20th but team management instructed the drivers to maintain the pre-determined pace.
All three Sauber-Mercedes entries had problems as the sun set. More trouble befell No. 63 during the evening when third driver Stanley Dickens hit a race official in the pit lane. Though the official was virtually unhurt, the impact bent the angle of the rear wing. While the car was refueled and new tires were fitted, mechanics straightened the aerofoil and Mass returned to the cockpit. By hour five, No. 62 was struggling with electrical problems that kept the engine from developing full power, forcing that machine to make several lengthy unscheduled pit stops that did little to improve the situation, while No. 61 almost crashed after another car spread oil over the windshield of the C9 and on the track, nearly causing driver Kenny Acheson to lose control on the slippery surface.
The opposition also suffered setbacks. The No. 3 Jaguar led for three hours before its gearbox got stuck in neutral. The Porsche No. 9 then took the lead with former Le Mans winners Hans Stuck and Bob Wollek sharing the controls. The pink and white entry set the pace for six hours until extra stops to deal with a water leak and slipping clutch slowed their lap times and caused them to drop back.
More problems delayed the Saubers. No. 61 was stationary for several long minutes while mechanics repaired the electronic timing device that had broken off its mounting. No. 62 collided with another car, suffering a broken radiator and nose that took some time to repair and replace. No. 63 spun twice at the hands of Reuter and Dickens, but neither move resulted in contact and the drivers simply motored to the pits to replace flat-spotted tires.
By half distance, Jaguar No. 1 led by a full lap over Sauber No. 61 with 63 in third. Jaguar No. 2 was fourth, two laps behind, and the Jaguar No. 4 was fifth, four laps off the pace. By 1 a.m., Jaguar No. 4 had dropped from contention as it lost nearly an hour having the gearbox rebuilt. Shortly after 6 a.m., the complexion of the race changed completely as Jaguar No. 1 pulled into the pits with another broken transmission. With nine and a half hours to go, Sauber-Mercedes racers were running in first and second positions.
The two Silver Arrows ran just a few hundred yards apart, swapping the lead during pit stops. Just after stopping and losing the lead at 7:30 a.m., Baldi was driving hard in No. 61 when he applied his brakes too late entering the Dunlop chicane. His car spun off into the surrounding sand trap and Baldi spent more than three minutes getting the car to move out of the soft hazard. He returned to the pits where new brake pads and a new nose were fitted, enabling No. 63 to build a lead of more than a lap. Despite its electrical problems, No. 62 had run consistently and rose to sixth as many opponents dropped out with mechanical failures.
All three Sauber-Mercedes ran without further incidents, stopping regularly for fuel and tires every 14 laps. During the final pit stops, the Sauber mechanics made a special effort to scrub more than 23 hours of grime from the three-pointed stars on the noses of the cars; Mercedes planned to finish with the cars in formation, creating a photo that told the full story of a dominant victory. But that was spoiled on the final lap as Stuck, in the third-place Porsche, blocked the fifth-place No. 62. So, No. 63 led No. 61 as they rounded the last turn. No one actually reached the checkered flag as fans climbed the fences and overran the main straight.
Officially, the Sauber-Mercedes entries placed first, second and fifth as Mercedes claimed its second win in the legendary French competition. By the numbers, No. 63 averaged 136.702 mph and completed 389 laps (3,272.27 miles). The winning car made 31 pit stops and used 2,469 liters of fuel, leaving 81 to spare. The team was especially pleased for Mass, the oldest of the nine drivers, who finally won at Le Mans after eight previous disappointments. Only 19 of 55 starters were running at the end.  
Compared with Le Mans, the races in the 1989 WSPC were sprints, running approximately 480 kilometers (300 miles). With two Silver Arrows contesting every round, the shorter distances had little effect on the outcome as Sauber-Mercedes won seven of eight races and scored three 1-2 finishes. Schlesser narrowly claimed the drivers’ championship from Baldi. More importantly, Mercedes gained an enormous amount of technical knowledge about how to make its production engines more powerful and more durable while improving fuel economy.
At the end of the year, two of the C9s were inducted into the Mercedes-Benz Museum in Stuttgart and today one of the cars sits proudly with other legendary Mercedes champions such as the 1937 W125, the 1954 W196 and the 1955 300SLR, while the other car occasionally appears on display, as at Amelia Island this year.   
Using racing to improve the road-going products of auto manufacturers continues to this day. The 2014 Formula 1 rules require that the cars get 35 percent better fuel mileage than in the past and utilize sophisticated hybrid energy recovery systems to allow engine manufacturers to develop technologies that can be transferred to production cars. Still, it is worth noting that in the last quarter century, no production-based engine has won a world championship in auto racing. The M119 was used in various Mercedes production cars – including the SL500, the 400E and the 500SEL – from 1989 to 1999. Many longtime Mercedes mechanics still regard the M119 as the greatest V-8 engine the company has ever created. A true classic is timeless.