800HP 5L V8 Sauber/Mercedes C9 | 24 Hours of Le Mans Champion [TECH TOUR]

What goes into a 400kph/248mph Le Mans 24 Hour endurance race winner and how do you keep such a car period correct, but also track fit? The Group C Sauber chassis and Mercedes-Benz ‘M119’ powered C9 managed the first win at the 1989 Le Mans 24 hours for Mercedes since 1952 with a 1-2-5 finish, and also wins at all but one race during the entire 89 World Sportscar Championship. If that doesn’t impress you, then we’re not sure we can be friends anymore...

At the Goodwood Festival of Speed, David Rowe of EPS Motorsport was kind enough to give us a run-down on some of the electronics and mechanical changes that have been made, including the edition of a MoTeC M800 ECU that is hidden inside an original style housing of the old Bosch ECU to keep the period-correct look while allowing the car to have modern safety parameters monitored in order to keep the essentially irreplaceable block intact but usable.

Along with the ECU this motorsport edition M119 V8 package has had the engine internals updated along with the injectors, however, the loom has been rebuilt to period spec with even the connectors used being from the same era plus fuses and relays are retained rather than being replaced by a PDM. A MoTeC L120 logger, CDI unit and MDD display have also been added to help with the performance of not just the car but also the drivers.

The boost control solenoid placement is not ideal by modern standards, however given the value and historic nature of the car David is not worried about a reduced torque hit (700 ft-lb) when the driver hits the noise pedal as while the original wastegates and KKK turbochargers look like the originals, just like the ECU internally they have been modernized internally in order to give the team more options for servicing and replacement, potentially along with a bigger service window.

Lastly we also touch on the twin injector setup that has been retained despite having modern injectors on hand, and why teams in that era ran two small injectors rather than one large one to begin with. Due to the quality of the Sunoco Race Fuel fuel used and the fact the engine is running at a comfortable sport rather than at the limit, knock is not a concern for David (who also tunes this car) and knock control strategies are therefore not required.

We’re happy to report that we saw David again after his run up the hill and love his saying ‘Wiring in a race car can only ever lose you races, never win you races.’

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