Under scrutiny: Sauber Mercedes

The star ascendant

Thirty years after Daimler-Benz’s withdrawal from racing, the Mercedes name returned to Le Mans in 1985 associated with Peter Sauber’s World Endurance Championship contender.

It was not an auspicious debut for the V8 twin-turbocharged car from Hinwil, near Zurich. An aerodynamic failure of some sort caused the car to fly high into the air at the end of the Mulsanne straight and give John Nielsen the ride of a lifetime, at over 200mph; the Dane was fortunate to escape unhurt when the car landed on its wheels. But from such a shaky start Peer Sauber has now welded a team that looks likely to challenge World Champions Jaguar all season.

The C8 model was developed from the BMW six-cylinder powered C7 which finished ninth at Le Mans in 1983, breaking Porsche’s stranglehold on the leaderboard. Before it was put to rest it won the 1986 Nürburgring 1000km race, a storm-torn event in which Mike Thackwell excelled on Goodyear’s rain tyres.

The current C9 model, which made its debut at Silverstone last May, uses a similar bonded sheet-aluminium chassis; while the car resembles its predecessor it is, in fact, a “clean-sheet” design executed by Leo Ress, formerly with BMW in Munich.

The chassis is stiffer than before, but may not yet be stiff enough, since the remaining weakness in the car, its tendency to overheat its rear tyres, is blamed partly on lack of torsional rigidity. That can only be a matter of development, and when the C9 does make its Michelins last through a 60-minute driver stint the Jaguars will face a truly formidable team.

The C9 had, straight away, twice as much ground-effect as the C8 (designers never divulge the exact figures!), and although the 1988 regulations have reduced the effect by enlarging the flat reference-plate below the monocoque and lowering the rear venturi, the Sauber opened the season in Spain by smashing the 1987 qualifying record. The Jaguar drivers were struggling to match last year’s times, and Jean-Louis Schlesser was on pole position at Jerez and Jarama by wide margins.

Last September’s Spa-Francorchamps 1000km race was a watershed for the team. The Yves Saint Laurent company had told Sauber that its Kouros sponsorship would not be continued in 1988. In response, Thackwell claimed the team’s first-ever pole position, led for four laps (until the driving-seat catch broke, of all the silly failures) and established a new lap record (the race was then led by Richard Lloyd’s Porsche, until the differential broke, and ironically Liqui Moly also announced that weekend that it would withdraw its support form the British team in 1988).

There were no angels waiting in the wings for Lloyd, but political stirrings at Daimler-Benz would prove to be of major benefit to Sauber.

Edzard Reuter, a finance man, had replaced Professor Werner Breischwerdt as the chairman of the Vorstand (board of management), which in itself was not promising. The deputy chairman, though, was Professor Dr Ing Werner Niefer, who was also the head of passenger-car development and was known to be a motor racing fan. What Tom Walkinshaw could do for Jaguar, he argued, Peter Sauber could do for Mercedes, and in December the Vorstand approved his plan to channel financial and technical support into Sauber’s operation (and also into various Mercedes 190 teams participating in the European Touring Car Championship).

By supporting independent teams, Mercedes could drop the pretence of not being involved in motor racing, but could distance itself from any major setbacks. An internal committee has been formed at Daimler-Benz, headed by Niefer, to define the company’s long-term racing objectives, and its members include Erich Waenberger, Gerhard Harle (who replaces Porsche’s Jürgen Barth as the manufacturers’ representative to FISA), aerodynamicist Rudiger Faul, and public relations man Bernd Harling.

When announcing Mercedes’ new involvement in January, Niefer stated: “We saw the potential of our V8 engine last year. This year we not only want to put it to the test in tough racing competition, but also want to know the challenges and opportunities in this specialised discipline, which is of great technical interest.”

That was no half-hearted statement, and the parallels with Jaguar and Tom Walkinghsaw Racing are very strong. Walkinshaw undertakes his own development of the V12 engine, whereas Sauber (with a much smaller operation) is happy to leave that largely to Mercedes, but both men carry a prestigious banner on behalf of rival manufacturers.

They would both like Porsche to return to the contest, with a new car, and relish the thought of having a two-year start on what will be a brand new Weissach design. Porsche’s 1989 challenger is already constructed, around the “Indy” V8 engine, but track development will not begin until the 2708 Indycar is competing successfully.

Le Mans is the prime objective for all three manufacturers: Porsche feels that there is some more victory left in the 962C design, and on last year’s form it would be hard to disagree.

The TWR Silk Cut Jaguar team has designed the XJR-9LM as a successor to the XJR-8LM, and testing has shown some significant gains in performance, though 24-hour reliability will remain the essential ingredient. Victory in the Daytona 24-Hour race in January has raised Jaguar’s hopes and prospects immeasurably, but still a whole host of factors have to work together: mechanical reliability, driver reliability and tyre reliability must be all be 100% in at least one of the three or four cars.

What, then, of Sauber-Mercedes? The Swiss team has had nothing but misfortune is its past three appearances at Le Mans, a tyre failure like Win Percy’s eventually stopping Thackwell’s C9 last year though with no disastrous consequence. Walkinshaw believes that it takes at least three attempts to learn how to win, but this is the fourth for Peter Sauber . . . could this be his year?

The C9 is fast enough – Johnny Dumfries established the Le Mans revised-track record last year in the Kouros entry – but until now the Sauber team has not been sufficiently professional in its approach to the classic race, a criticism which can no longer be applied.

This may not be the year of the Sauber-Mercedes at Le Mans, for it may take another year of support from the Stuttgart firm to complete the recipe, but prospects for the race in June are fascinating, and those for 1989 even more exciting.

With the power-units themselves, Mercedes also supplies four engine technicians for each race and a van-load of telemetric equipment, all under the supervision of Ing Herman Hiereth. The team is managed by Max Welti (entered as a co-driver at Le Mans in 1985), and drivers nominated so far are Jean-Louis Schlesser, Mauro Baldi and Jochen Mass.

Schlesser will also take part in the German Supercup series, having won the last round of 1987 at the Nürburgring, and a fourth driver will be nominated in time for the Silverstone 1000km on May 8, the first time that Sauber will run two cars. It is likely that Stefan Johansson will be the nominee, although due to clashing Formula One commitments he will not be available for Le Mans, Brno or Brands hatch, and James Weaver has been invited to drive a Sauber at Le Mans; team-leader Schlesser, though, declines to compete at Le Mans for safety reasons.

Any financial worries were removed by Daimler-Benz prior to the start of the year, and five million Deutschmarks is the reputed sum put up by AEG-Olympia, a DB subsidiary. The car is even darker navy-blue than before – almost black – and is also sponsored by Michelin and by Castrol.

Mercedes’ commitment to the programme continues to the end of 1990, while Gallaher’s with Jaguar extends to the end of 1991, so the immediate future of sports-prototype racing is guaranteed no matter what FISA may wish.

The opinion is growing that FISA would like to downgrade the Group C category to “International” (instead of “World”) status as soon as possible, to promote the so-called Procar series over its head in 1990. Bernie Ecclestone’s plan is to involve at least six manufacturers in his “made for TV” Procar series, at a cost per team perhaps exceeding that of Formula One, but at present only Alfa Romeo has declared any positive interest.

Unless FISA can exert irresistible pressure on five more manufacturers, Procar would appear to be a non-starter, and it is possible that Jaguar, Mercedes, Porsche, Nissan, Toyota and Mazda would offer to prepare their Group C cars for such a series, perhaps as part of the World Championship.
Mercedes is no longer represented on the tracks by silver cars adorned by the three-pointed star, but its presence has quickly become a major force.

With the level of commitment now shown, even in the first three rounds of the 1988 World Championship, it is impossible to imagine that Peter Sauber’s team aims to go anywhere but forwards –to victory at Le Mans and the World Championship. MLC

Under the skin of the Sauber C9/88

The Sauber C9/88’s monocoque is a straightforward sheet-aluminium bonded structure, and the Mercedes type M117 five-litre V8 engine is attached as a semi-stressed member.

Front suspension features a wide-based lower wishbone, top camber and castor links, and outboard springs around Bilstein gas dampers. The tubular front anti-roll bar is operated by push- and pull-rods and a chassis-mounted rocking arm, giving infinite adjustment and a rising-rate roll stiffness.

Rear suspension is highly innovative, locating the rear springs and dampers horizontally and facing the front of the car, supported by engine bearers. The springs and dampers are compressed by machined aluminium rockers which are actuated by pull-rods attached to the outer ends of the top wishbones. The tubular anti-roll bar is linked to the same rockers.

This tidy layout takes the suspension hardware upwards and well clear of the venturi, which was part of a particular benefit last year when the tunnels were taller than they are today (in line with the latest regulations, the tunnels may be no more than 27cm higher than the chassis floor, approximately reaching the rear hubs).

Unlike the C8, the C9 features a front-mounted water radiator, thus improving weight-distribution, the flanks now housing the twin-turbo intercoolers and oil coolers. Turbochargers are from KKK, but Sauber makes his own wastegates.

The C9’s rear wing is mounted on the gearbox (rather than on the bodywork, in conventional Porche fashion) and all the bodywork is made of Kevlar sandwich. On average the C9 weighted 880kg last year, any savings in construction only compensating for the Hewland VGC transmission, which was heavier than the VG used previously.

Last year the engines were prepared by Heini Mader, and were said to give between 700 horsepower at 0.8-bar boost (11.28lb) and 840 bhp at 1.2-bar boost (16.9 lb). This year the engines are prepared by Mercedes, and supplied from Stuttgart with the latest Bosch Motronic 1.7 system similar to that used on the TAG-Porsche Formula One unit last season. Power is virtually unchanged but fuel economy is improved, and the latest torque figures given are 1000Nm (737 lb ft) on full boost, and 800Mn (590 lb ft) on race settings.

This proved too much for the VGC transmission and driveshafts last year, resulting in several breakages; but during the winter Ress, together with Mercedes engineers and the British company Staffs Silent Gears, worked out a solution which produced a totally reliable race package for Jerez (a punishing circuit) and Jarama.

Intriguingly, Mercedes has perfected a stress gauge on the driveshafts which retards the engine’s ignition when a certain toque figure is exceeded, this apparently being a spin-off form the firm’s ASD anti-slip control for the rear wheels, similar to that raced by Volvo in 1986, is also under development, and Mauro Baldi has first-hand experience of that system.

Other changes on the C9/88 raced in Spain include the fitment of Brembo braking (as used on the Lancias between 1983 and 1986, and by Richard Lloyd) instead of AP equipment, and the adoption of Speedline wheels instead of BBS. The Front wheels have been increased from 16in to 17in diameter, but the rear wheels remain at 19in. MLC