BMW has unveiled the most powerful production engine in its history. Revving to 8 250 r/min, the F1-inspired 40-valve 5,0-litre V10 produces 25 per cent more power than the previous M5 engine.
BMW has unveiled the most powerful production engine in its history. Revving to 8 250 r/min, the F1-inspired 40-valve 5,0-litre V10 produces 25 per cent more power than the previous M5 engine.
BMW M GmbH claims the engine, which consists of two five-cylinder banks arranged at an angle of 90-degrees, produces peak power of 378 kW and a maximum torque of 520 N.m.
To maximise stiffness and resist the high loads resulting from combustion pressure, engine speed and vibrations, a bedplate design has been chosen for the crankcase. The crankshaft is supported by six bearings and grey-cast iron inserts have been integrated into the aluminium bedplate, which the company says enhances the engine’s acoustics, increases vibrational comfort and ensures a high oil supply rate.
Earmarked to do duty in the new M5, the engine marks the first time BMW has used a bedplate design for a production V-engine. The one-piece aluminium cylinder heads of the V10 engine are arranged in banks. The M engine has low-weight, flow-optimised 5 mm-shaft valves, spherical valve tappets with hydraulic valve play compensation and single valve springs.
Bi-VANOS variable valve timing was used to optimise the engine’s charge cycle, resulting in increased performance, an improved torque curve, optimum responsiveness, lower consumption and fewer emissions. The naturally aspirated engine uses ten flow-optimised intake trumpets to “inhale” air from two intake plenums. Each cylinder has its own throttle. The throttles are actuated simultaneously and electronically controlled.
The exhaust system of the new M5 engine is made of seamless stainless steel and has a dual-flow design. The exhaust gases leave the system through the M trademark four tailpipes.
The MS S65 engine management system conducts ionic current measuring throughout the combustion process. The ionic current satellite receives signals from the five spark plugs of each cylinder bank. Dependent on the load, it amplifies these signals and transmits them to the engine management system for analysis, which, for example, adjusts the ignition point of each cylinder via knock control to the combustion process.
Sophisticated seven-speed SMG gearbox
The powerplant will be mated to a seven-speed sequential gearbox with drivelogic function. SMG allows gears to be changed using the central gearshift lever or via paddles mounted on the steering wheel. Compared with the previous SMG transmission, gear change times are said to be 20 per cent faster .
The SMG’s drivelogic function allows the driver can choose from 11 gear change options. Six of the programs can be preselected in the sequential manual gearbox mode (S mode), the spectrum ranges from balanced dynamic to very sporty. With the gearbox in the S mode, the driver shifts gears manually. Whenever the driver activates the Launch Control function, the SMG Drivelogic shifts gears shortly before the maximum engine speed and with optimum slip until the M5 reaches its top speed.
In the D (Drive) automatic gearshift mode, the transmission shifts the seven gears automatically, depending on the program selected, the driving situation, the road speed and the position of the accelerator pedal.
When a driver shifts down on a slippery surface, for example, the SMG gearbox opens the clutch in the fraction of a second in order to prevent the M5 from swerving out of control in the event of excessive drag torque at the driven wheels, BMW claims.
An anti-roll feature prevents the car from rolling backwards during hill starts. A hill detection programme adjusts the shift points on gradients and descents. For down hill runs, hill detection holds the lower gears for longer in order to make effective use of the engine’s braking power, the manufacturer says.
