Mercedes-AMG Project One — F1 power, complexity for the chosen few

By Christopher A. Sawyer
The Virtual Driver

(September 18, 2017) More than 1,000 horsepower. A top speed of more than 217 mph. Formula 1 hybrid technology. It is, says Dieter Zetsche, chairman of Daimler AG’s board of management and head of Mercedes-Benz Cars, “…the first Formula 1 car with MOT (Ministry of Transport) approval.”  Uh, well, sorta.

Unlike those F1 cars Mercedes engineers and pays for, the Project One is a plug-in hybrid two-seater with two electric motors that drive the front wheels. Like the F1 cars, it is powered by a 1.6-liter turbocharged, direct-injected V6 whose four overhead cams are driven by spur gears, not belts or chains.

The single turbocharger (or MGU-H — Motor Generator Unit-Heat — in F1 parlance) splits the turbocharger in half, with the turbine on the exhaust side and the compressor wheel on the intake side of the engine, joined together by a long shaft. This shaft runs through an electric motor of approximately 90 kW (121 hp), and electric power can be used to drive the compressor turbine at speeds up to 100,000 rpm to eliminate turbo lag. It also scavenges surplus energy, and either dumps it into the high-voltage lithium-ion battery pack, or feeds it to a 120 kW (161 hp) electric motor (the MGU-K, or Motor Generator Unit-Kinetic) that is attached to the engine and provides power directly to the crankshaft via a spur gear.

In keeping with its F1 roots, the valves use a pneumatic actuation system instead of valve springs. This eliminates valve float, speeds valve movement, and increases the engine’s rpm limit. This is especially important in F1 where engine speeds of nearly 20,000 rpm are not uncommon.

However, it also comes in handy for a “street” motor that has a rev limit of “just” 11,000 rpm. The reduction in engine speed, says Mercedes-AMG, makes it possible for the engine to run on Super Premium unleaded fuel. In addition, the company says the hybridized powerplant will have a thermal efficiency of over 40%, though you have to marvel at the level of cost and complexity necessary to add the two-to-seven percent increase over the best conventional series production engines available today.

Where the powertrain diverges the most from F1 practice, however, is in the use of a pair of 120 kW motors to drive the front wheels. It allows the individual acceleration and deceleration of each wheel. This torque vectoring capability should not only make the Project One extremely agile, but Mercedes-AMG estimates that under optimal conditions the motors will be able to recover up to 80% of braking energy in everyday driving conditions.

The battery cell design, arrangement, and the cooling system that keeps them from exceeding optimal temperature is the same as used on the Mercedes-AMG F1 car. The battery, however, is larger so as to provide up to 25 km (15.5 miles) of electric-only driving range.The battery pack and DC/DC converter are located in the vehicle floor behind the front axle. In addition, the electrical system operates at 800 volts instead of 400, and this brings significant reductions in the size and weight of the cables.

Another area of difference is in the transmission used. The Project One has a unique eight-speed manual gearbox designed exclusively for the car. Like the F1 unit, it is hydraulically activated, but can be operated in both automatic and manual modes. Oh, and unlike the F1 system, neither the engine nor the transmission have to be carefully run-in using pre-heated oils and fluids from cold due to exceedingly tight tolerances.

Both the front and rear suspensions are multi-link designs, though the rear suspension is mounted directly to the engine/transmission unit. The pushrod coil-over units are installed laterally across the car, perpendicular to the vehicle’s direction of travel. Mercedes-AMG claims this layout replaces the need for conventional anti-roll bars, prevents roll even during rapid direction changes, and does not adversely affect ride.

The Project One wears 285/35ZR-19 tires on 10J x 19 wheels up front and 335/30ZR-20 tires on 12 J x 20 wheels in the rear. The wheels are 10-spoke forged aluminum wheels with a center-lock nut and an aerodynamically optimized carbon fiber cover. Carbon ceramic brakes are used at each corner.

A central air intake runs over the roof, and merges into a vertical shark fin that improves lateral stability at speed. This combination splits the rear window — there to allow passersby to see the power unit as much as to improve rear visibility — and leads to a pair of large NACA ducts that feed air to the engine and transmission oil coolers. Up front, the splitter extends automatically to increase downforce, and the active ventilation louvers in the front fenders open. In the rear there is a surprisingly abrupt vertical spoiler lip and a double diffuser that is interrupted only by the centrally located exhaust pipe

Inside, the individual seats feature adjustable backrests, but are bolted to the floor. Both the steering column and pedals extend or retract to adjust to the driver. The instrument panel is a functional structural component that places two high-resolution free-standing displays the driver’s field of vision. One is slightly raised and located directly in front of the driver, while the other is located to the right of the center console and angled toward the driver.

To drive home the F1 similarities, the steering wheel has flattened upper and lower sections, as well as a pair of integrated controllers that adjust things like the LED shift display in the wheel’s upper section, driving modes and suspension settings. A roof-mounted aluminum housing holds a screen that displays real-time images from the rear camera. Thus the driver gets an unencumbered view to the rear, something that would not be possible with the split rear widow and a conventional rearview mirror. More encumbered is the buyer’s bank account.

Each of the 275 production versions of the Project One — all of which are spoken for — have been sold for $2.72 million each.

The Virtual Driver