Mercedes-Benz Sauber C9

Lore & Background

The C9 was a development of Sauber's previous C8 design, retaining a monocoque that largely consisted of aluminium, although considerably stiffer and with numerous other improvements. The rear suspension changed from vertically positioned spring/damper units arranged over the top of the gearbox to a horizontal layout aligned with the longitudinal axis of the car. Aerodynamic changes included the repositioning of the combination of oil/water radiator to the nose of the car, which allowed the use of a modified splitter plate. Commensurate with the repositioning of the radiators, the large NACA ducts were removed from the top of the door sills. The rear deck had been considerably re-profiled and the rear wing was now mounted solely on a central support. Aerodynamically, the car had two configurations: one for sprint circuits and a low drag version for the 5.8 kilometre Mulsanne Straight at Le Mans. In its sprint configuration, it produced 2,222.1 kg (4,899 lb) of downforce at 320 km/h (200 mph) while generating 555.7 kg (1,225 lb) of drag. The sprint circuit configuration had a L/D ratio of 4:1 while the low drag version was around 3:1. The early engines were again prepared by Swiss engine specialist, Heini Mader, though this is now known to have been a cover for Mercedes back door involvement with the project later on. It had been progressively lightened with the use of a new crankshaft, higher efficiency KKK turbochargers and a liner-less block. It was a semi-stressed part of the chassis and ran a dry sump. There were no special qualifying engines and on 2.2 bar of boost it was said to be rated at 'almost 800 hp (811 PS; 597 kW)'. Maximum race boost was 1.9 bar. Maximum RPM was 7,000 but drivers generally kept to 6,500 during races. The torque curve was almost uniform between 3,000 and 6,000 rpm, giving the engine plenty of flexibility. The engine retained a cross plane crankshaft and the firing order was 1-5-4-8-6-3-7-2. Later M119HL engines were sourced from the Mercedes engine facility at Untertürkheim, supervised by Hermann Hiereth. The addition of 16 valve heads in 1989 took power up by about 20 hp (20 PS; 15 kW) to around 720 hp (730 PS; 537 kW) at 1.6 bar and 7,000 RPM. The increase in fuel efficiency meant absolute power could also be taken from just under 800 hp with 2.2 bar of boost to about 820 hp (831 PS; 611 kW). For its debut season in 1987, the

In Their Own Story

The roar of the M119 V8 engine echoed through the morning mist at Le Mans as Stefan Bellof pushed the C9 to its absolute limit during a practice session in 1987. The car, painted in the iconic silver and black livery, sliced through the air with terrifying speed, its turbocharger whistling like a banshee before unleashing a surge of power that left spectators breathless. In those fleeting moments, it was clear to everyone watching from the grandstands that this machine was not just competing; it was rewriting the rules of what was possible on the track.

Reader's Guide

The Sauber C9 did not enjoy a lot of success in 1987, its first season, finishing on only three occasions. The car's speed potential was made clear when Johnny Dumfries set a lap record at Le Mans before retiring with gearbox failure. Mike Thackwell also took pole position at Spa. Schlesser won the final race of the year, the non-championship Nurburgring Supercup, which was the only win in an otherwise bleak season for the Swiss-German team. The C9 won five races in the 1988 World Sportscar Championship, showing much-improved reliability and placing second in the overall standings behind the winning Silk Cut Jaguar team. Drivers Schlesser, Baldi and Mass finished second, third and fifth respectively behind Jaguar's Martin Brundle in the driver's championship. In the 1989 World Sportscar Championship, the Sauber C9 won all except the second race at Dijon Prenois, where they were defeated by the Joest Porsche 962 of Bob Wollek and Frank Jelinski. Sauber drivers also filled the top four spots in the drivers standings with Schlesser winning the championship outright. High performance was only one notable aspect of the C9s ability; its reliability was another. The car failed to finish only twice in the 1989 season but on both occasions, the race was won by the other team car. Reaching 400 km/h (248.0 mph) during the qualifying sessions of the 1989 24 Hours of Le Mans, the Sauber C9 proved to have one of the highest top speeds in the history of the competition at Le Mans. The C9's mark was only exceeded by the WM Peugeot P88, which achieved a speed of 405 km/h (251.1 mph) in the 1988 race, however both of these cars were purpose built to achieve a top speed record, with one vehicle retiring after only 13 laps, in stark contrast to the C9's bulletproof reliability over the whole of the 24 hours. These speeds led to the introduction of two chicanes on the Mulsanne Straight from 1990 onwards.

Did You Know?

• The Sauber C9 was introduced in 1987, not 1984.
• The C9 won the 24 Hours of Le Mans only once, in 1989.
• The winning car at the 1989 Le Mans was driven by Jochen Mass, Manuel Reuter, and Stanley Dickens, not Derek Bell.
• Stefan Bellof died in 1985, before the C9 was built, so he could not have set a lap record in it.