The drive System of the new BMW M5

1.World premiere of the new BMW M5's drive system. (Short story) (page
3) 2.The new V10 engine in the BMW M5:A masterpiece in engine
construction. (page 8) 3.The new sequential M transmission:Shifting
gears even faster with the seven-speed SMG gearbox. (page 20) 4.The BMW
M5 engine production:Engine construction at its best. (page 24) 5.Torque
Diagram. (page 27) World premiere of the new BMW M5's drive system.
Whenever BMW M GmbH presents a new M automobile, the focus of attention
is traditionally on the power unit beneath the bonnet. This is
particularly the case with the new M5: across the world, its V10 engine
is considered to be one of the most fascinating drive concepts featured
in a production car. This technological masterpiece does not only sport
the same number of cylinders as its Formula 1 BMW WilliamsF1 racing
counterpart, but also shares its high-revving concept. As is the case
with all high-performance normally aspirated engines made by BMW M,
this power unit generates enormous pulling force over the entire speed
range. First high-revving V10 engine to be featured in a
regular-production saloon. The V10 is the only high-revving power unit
to be featured in a series-production car. The M5's engine has ten
cylinders, a cubic capacity of 5 litres and produces a maximum output
of 507 bhp and a maximum torque of 520 Newton metres, making the M5 the
most powerful final production model in the BMW line-up. The segment of
powerful sports saloons was introduced 20 years ago with the
presentation of the first M5 and this new engine once again sets the
benchmark in this particular segment. There is, however, more to it than
pure performance. What is important for M automobiles is acceleration
and driving dynamics, the latter which is dependent on the actual
forward thrust and the vehicle's weight. The drive forces at the driven
wheels are significantly influenced by the engine torque and the
transmission ratio. The high-revving concept caters for an optimum
transmission ratio, thus guaranteeing an impressive forward thrust.
The perfect choice: high-revving concept. For the BMW M engineers the
compact, high-revving normally aspirated engine was the ideal choice.
With a red line of 8,250 rpm, the ten-cylinder engine has ventured into
terrain which has so far been reserved for red-blooded racing cars.
Compared to the previous M5 eight-cylinder engine, performance has
increased by more than 25 per cent. The M5 has also surpassed the
magical 100 bhp per litre limit, its specific output being on par with
that of racing cars. A masterpiece in engine construction. BMW, one of
the leaders in engine construction, has made a name for itself
primarily as a manufacturer of inline engines. The two five-cylinder
banks of the V10 are arranged at an angle of 90¡ã to
achieve a mass balance of the crankshaft drive, which is optimized for
low vibration and increased comfort. For reasons of stiffness, that is
due to 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, grey-cast iron inserts have
been integrated into the aluminium 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. Every gram counts in
lightweight construction. The one-piece aluminium cylinder heads of the
V10 engine are arranged in banks. The V10 power unit features four
valves per cylinder, a layout which is typical of BMW engines. 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 realisation of the
high-revving concept. High-pressure bi-VANOS for an optimum charge
cycle. 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.
Individual throttle butterflies help the engine to breathe freely. The
naturally aspirated engine uses ten flow-optimized intake trumpets to
"breathe in" 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. Dual exhaust system made of stainless steel. 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 finally leave the system through four tailpipes which are what
make the rear end of the M vehicles so unmistakable. The exhaust system
complies with the European EU4 and the US LEV2 emission standards. The
engine control module: the first of its kind in the world. 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 ones which
are 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.
Highlight in engine management: ionic current technology. 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. The ionic current measuring is done
directly during the combustion process. The so-called 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. Seven-speed SMG gearbox conveys M power to the tarmac. The
high-revving concept only succeeds in combination with a gearbox which
translates the torque available to the engine, by means of a short
overall transmission ratio, into optimized forward thrust. The
seven-speed SMG gearbox is precisely the right transmission to ideally
convey the V10 engine's power via the drive train to the wheels. BMW M
is the first manufacturer worldwide to offer a seven-speed sequential
gearbox with drivelogic function. Even more highly perfected 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 automatic gear selection. The purpose of
the additional seventh gear is to reduce engine speed and torque gaps.
New SMG gearbox's speed up by 20 per cent. With the seven-speed SMG
gearbox, gears can be changed using the central gearshift lever or the
so-called paddles on the steering wheel. Compared to the previous SMG
transmission, changing gears is 20 per cent faster with the new SMG
generation. Never before has it been quicker to change gears with a
transmission of this kind. The advantage for the M5 driver: Gear change
is smooth and accomplished at a speed impossible to reach even by the
most proficient driver, thus making the inevitable power flow
interruptions when changing gears hardly noticeable. The M5 delivers an
almost jerk-free performance when accelerating from a standstill to its
top speed. Drivelogic: the driver determines the SMG's characteristics
for changing gears. Thanks to the SMG's drivelogic function, the driver
can choose from eleven gear change options, which enable him to adapt
the SMG's characteristics to his very own style of motoring. Six of
these programs can be preselected in the sequential manual gearbox mode
(S mode), the spectrum ranging 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. SMG for increased safety and
comfort. 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.
Further functions are the climbing, which prevents the car from rolling
backwards during hill starts as well as the hill detection, which
adjusts the shift points on gradients and descents. This prevents gear
hunting when going uphill. When driving downhill, the hill detection
holds the lower gears for longer in order to make effective use of the
engine's braking power. Production of high-performance engines - engine
production at its best. 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 demandsthe
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
aggregate. As the materials and components of the high-revving engine
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 1¨M1000 millimetres. 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.