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Motor |
The compact, high-revving normally aspirated engine boasts a red line of
8,250 rpm.
Compared to the previous M5 V8 engine, performance has increased by a
massive 25 per cent. In keeping with its racing bloodline, the M5 surpasses
the magical 100 BHP per liter output, its specific output being on par with
that of racing cars.
BMW, one of the leaders in engine construction, has made a name for itself
primarily as a manufacturer of inline engines. But its V-engines are also
something extremely special.
The two five-cylinder banks of the V10 are arranged at an angle of
90-degrees to achieve a mass balance of the crankshaft drive, optimized for
low vibration and increased comfort.
To ensure maximum stiffness and resist the high loads resulting from
combustion pressure, engine speed and vibrations, a bedplate design has been
chosen for the crankcase.
For an optimum alignment of the crankshaft,
gray-cast iron inserts have been
integrated into the aluminum bedplate, which also serve to enhance
acoustics, increase vibrational comfort and ensure a high oil supply rate.
The extremely stiff crankshaft is supported by six bearings. In the new M5,
it is the first time that BMW has used a bedplate design for a production
V-engine.
The one-piece aluminum cylinder heads of the V10 engine are arranged in
banks.
The V10 power unit features four valves per cylinder, a typical BMW trait.
All valve train components are of low mass. Thus, for example, the M engines
feature for the first time low-weight, flow-optimized 5 mm-shaft valves,
spherical valve tappets with hydraulic valve play compensation and single
valve springs. All this results in a considerable mass reduction, which is a
prerequisite for the realization of the high-revving concept.
The bi-VANOS variable valve timing featured in the new M5 engine ensures an
optimum charge cycle, thus helping to achieve extremely short adjustment
times.
This means in practice: increased performance, an improved torque curve,
optimum responsiveness, lower consumption and fewer emissions. Thanks to the
bi-VANOS technology, intake and outlet valves are always opened and closed
at precisely the right moment.
The naturally aspirated engine uses ten flow-optimized intake trumpets to
inhale air from two intake plenums. Each cylinder has its own throttle, a
feature typical of racing cars. All throttles are actuated simultaneously
and are electronically controlled in order to make the engine highly
responsive in the lower speed range, as well as to achieve an immediate
response of the vehicle at the high end of the performance spectrum.
The exhaust system of the new M5 engine is made of seamless stainless steel
and has a dual-flow design all the way to the silencers. The exhaust gases
leave the system through four tailpipes, now a regular M trademark. The
exhaust system complies with the European EU4 and the US LEV2 emission
standards.
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The MS S65 engine management system is the central factor behind the V10's
outstanding performance and emission data. With more than 1,000 individual
components, this engine management system is unparalleled in its package
density. Its processors are the most powerful currently approved for use in
automobiles, as high engine speeds and comprehensive management and control
tasks demand the utmost from this system. |
Receiving more than 50 input signals, this system calculates for each
individual cylinder and for each individual cycle the optimum ignition
point, the ideal cylinder fill, the injection quantity and the injection
point. At the same time this system calculates and makes the necessary
adjustments for the optimum camshaft angle and the optimum position of the
ten individual throttles.
The ionic current technology featured by the engine management unit is a
technological highlight which serves to detect engine knock, misfiring and
combustion misses.
Utilizing the spark plug in each cylinder, this system helps to pinpoint
engine knock, to check for correct ignition and to detect any ignition
misses. Thus the spark plug has a dual function - as an actuator for the
ignition and as a sensor for monitoring the combustion process.
Ionic current measuring is done directly during 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, perfectly adjusts the ignition point of each cylinder via knock
control to the combustion process. All this results in benefits for the
driver of the new M5 - lower fuel consumption, higher torque and enhanced
performance.
The high-revving M5 maximizes the driver enjoyment quotient via a new
seven-speed gearbox optimized for split-second changes.
BMW M is the first manufacturer worldwide to offer a seven-speed sequential
gearbox with drivelogic function. Even more highly refined than the previous
six-speed transmission, the seven-speed SMG gearbox enables manual gear
selection with ultra-short shifting times as well as comfortable cruising
thanks to the automatic gear selection mode. The purpose of the additional
seventh gear is to reduce engine speed and torque gaps.
The new seven-speed SMG gearbox allows gears to be changed using the central
gearshift lever or via paddles mounted on the steering wheel. Compared to
the previous SMG transmission, gear change times are increased by 20 per
cent. The advantage for the M5 driver is a smooth and super slick
gear-change, accomplished at speeds impossible to reach even by the most
proficient driver, thus smoothing out the traditional imperfections in the
power flow through the gears. The M5 delivers an almost jerk-free
performance when accelerating from a standstill to its top speed.
Thanks to the SMG's drivelogic function, the driver can choose from eleven
gear change options, which enable them to adapt the SMG's characteristics to
their very own style of motoring.
Six of these programs can be pre-selected 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 always shifts gears manually.
Whenever the driver activates the Launch Control function, the SMG
Drivelogic shifts gears shortly before the maximum engine speed is reached
at precisely the right moment 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.
The seven-speed SMG gearbox not only supports the driver in achieving motor
sports performance, but also offers scores of safety features. In critical
situations, when the driver shifts down on a slippery surface, for example,
the 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.
An anti-roll feature prevents the car from rolling backwards during hill
starts. A hill detection program adjusts the shift points on gradients and
descents. This prevents gear hunting when charging up a long hill. 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 high-performance power unit featured in the new BMW M5 reflects the
engineering competence of the BMW engine construction specialists.
The most powerful production engine in the company's history is manufactured
along with other BMW special engines on a highly flexible production line at
the BMW plant in Munich.
The wide selection of products requires very agile processes and demands the
utmost flexibility, profound product knowledge and skilful craftsmanship
from the qualified staff.
The most stringent quality standards are met in the mechanical production
and assembly of the high-revving engine. As the materials and components are
exposed to heavy loads, extremely high demands are placed on surface quality
and production tolerances.
Some parts and components are processed at a precision of up to one
thousandth of a millimeter.
The coding of the core components enables the staff to keep track of each
individual component from goods receipt to processing and through to
installation. A storage medium is provided for each engine to ensure, by
data transfer to the assembly stations, that the right parts and tools are
used.

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