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X5 M & X6 M - E70/E71 (2010 - ...) - The M TwinPower Turbo

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X5 M & X6 M - E70/E71 (2010 - ...)
Brief
X5 M and X6 M
Design
The M TwinPower Turbo
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Specifications
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The M TwinPower Turbo

Twin Scroll Twin Turbo Technology with the joint exhaust manifold on both rows of cylinders making its debut.

With the model portfolio being enlarged through the addition of two all-wheel-drive BMW M Cars, the engine range is likewise being enhanced through spectacular new technology: Both the BMW X5 M and the BMW X6 M come with a truly outstanding power unit ranking right at the top in the current engine range of BMW M GmbH in terms of both output and torque.

In this case the power and dynamism so typical of BMW M is provided by a new and truly unique construction principle, the new M TwinPower Turbo with Twin Scroll Twin Turbo Technology and a common exhaust manifold for both rows of cylinders ensuring extremely spontaneous and direct behaviour, linear build-up of power and an unusually consistent torque curve.

The V8 power unit develops maximum output of 408 kW/555 hp at an engine speed of 6,000 rpm. Peak torque of 680 Newton-metres or 501 lb-ft, in turn, is maintained consistently throughout a wide speed range from 1,500 to 5,750 rpm.

With its displacement of 4,395 cc, the new M TwinPower Turbo delivers its exceptional power through particularly sophisticated turbocharger technology. Indeed, the V8 power unit with Twin Scroll Twin Turbo Technology and an exhaust manifold spanning both rows of cylinders represents the absolute state of the art in turbocharging. No other turbocharged engine offers a comparable combination of spontaneous torque and pulling power, a steadily rising power curve typical of BMW M, and maximum efficiency all in one.

Further outstanding features to be admired on the new M TwinPower Turbo are the special BMW M pistons and camshafts as well as the cooling system almost completely new from the ground up. To optimise the cooling circuit in accor­dance with the exceptionally high output per litre of the engine, the technology already featured on the V8 power unit in the BMW X6 xDrive50i and the new BMW 750i has been significantly modified and upgraded to an even higher standard. Dropping the water reservoir in the V-section between the two rows of cylinders, for example, the responsible engineers have succeeded in reducing not only the amount of coolant, but also the weight of the system.

Together with other features, a second low-temperature radiator with an additional electrical coolant pump improves the intercooling function on the new M TwinPower Turbo. This optimises the performance of indirect intercooling in particularly dynamic driving cycles. And last but not least, an additional electrical coolant pump with an after-running function serves to cool the bearing mounts on the turbochargers after switching off the engine.

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Turbochargers and catalytic converters in the V-section between the two rows of cylinders.

The highly innovative turbocharging system results from both the arrangement of the turbochargers and the supply of air. Together with the catalytic converters, the two turbochargers are positioned in the V-section between the two rows of cylinders at a 90° angle. This special position already to be seen on the eight-cylinder power units featured in the BMW X6 xDrive50i and the new BMW 750i allows unusually compact dimensions and arrangement. At the same time it requires intake and outlet ducts in a new position, reducing the length of the pipes and allowing larger cross-sections significantly minimising pressure losses on the exhaust side.

A further advantage of this arrangement is the shorter distance between the combustion chambers and the primary exhaust gas management systems. As a result, the catalytic converters reach their optimum operating temperature even more quickly after starting the engine.

Perfect guidance of gas flow: the dual-cylinder exhaust gas manifold.

Patented by BMW, the common flow of exhaust gas for both rows of cylinders ensures optimum gas throughput under all conditions. BMW’s new M ­TwinPower Turbo is indeed the first power unit in the world to feature such an unprecedented exhaust manifold.

This particular configuration is made possible by arranging the exhaust gas turbochargers and the catalytic converters in the V-section between the two rows of cylinders. The unique principle of the dual-row exhaust gas manifold thus provides the basis for the exceptionally spontaneous and direct response of the M TwinPower Turbo.

The system features no less than four completely separated exhaust gas pipes to provide this new technology. Two pipes on each side flow into each of the two Twin Scroll Turbochargers, merging together shortly before they reach the turbine. This provides a consistent and intense supply of exhaust gas ensuring a spontaneous and direct response and maintaining consistently high turbocharger pressure.

Functioning independently of the respective row of cylinders, the four exhaust gas ducts are allocated to those two combustion chambers which have a firing interval of 360° ideal for a V8 power unit in the efficient use of exhaust energy. This provides a steady and constant rhythm of gas flow in each of the two exhaust ducts, an effect further enhanced by the identical length of each duct on the exhaust gas manifolds linked to one another. The result is a consistent level of pressure acting on the two turbochargers, without any kind of counter-flow or adverse pressure.

The Twin Scroll Turbochargers specially developed for the new M turbo engine excel through their particularly high level of compressor and turbine efficiency, with the system operating at maximum charge pressure of 1.5 bar.

The Twin Scroll Twin Turbo power unit with its dual-cylinder exhaust gas manifold uses the potential of turbocharger technology in a unique manner. The extremely spontaneous and direct response of the system and the unusually high level of torque and pulling power extending all the way up from low engine speeds and constantly maintained up to a high load level are the characteristic features of the new M TwinPower Turbo. This truly impressive development of power is accompanied by fascinating engine sound highlighting the free-revving characteristics and the linear build-up of power through that typical, thoroughbred sound effect so characteristic of a BMW M Car.

Standing out clearly from the conventional sound of a V8 with its low frequencies, the M TwinPower Turbo develops a completely different and absolutely unique sound pattern with its sporting characteristics borne out in particular by the dual-cylinder exhaust gas manifold.

The introduction of map-controlled exhaust gas flaps in the exhaust system furthermore offers the option to clearly distinguish also in acoustic terms between the various settings in the Power Mode – the Sports and Efficiency driving programs, each standing out through their very distinctive engine sound.

The twin-chamber exhaust system on the new M TwinPower Turbo is characterised largely by straight pipes and a large cross-section. The two exhaust pipes merge into a common silencer at the rear leading on to the two dual tailpipes so typical of BMW M with their chrome trim right at the end.

Acceleration in the BMW X5 M and the BMW X6 M is ultra-powerful and dynamic right from the start, with huge thrust from the ground up. Both models reach 100 km/h from a standstill in just 4.7 seconds, continuing to accelerate at a fascinating pace all the way to top speed.

Top speed of both models is limited electronically to 250 km/h or 155 mph. As an option, however, this self-imposed speed limit may be raised to 275 km/h or 171 mph in conjunction with the optional M Driver’s Package. This also includes BMW Driver Training on a race track giving the discerning motorist the final qualifications for such outstanding performance.

Supreme efficiency in the segment thanks to ­High Precision Injection and BMW ­EfficientDynamics.

The new M TwinPower Turbo develops its outstanding performance not only through supreme power and muscle, but also with a degree of efficiency unparalleled in this segment.

This superiority is attributable largely to the fuel supply system, ­
High Precision Injection with piezo-injectors positioned between the valves ensuring a particularly precise supply of fuel.

­High Precision Injection uses injectors positioned directly next to the spark plugs in the cylinder head and supplying fuel to the combustion chambers at a pressure of 200 bar. The cooling effect provided through the direct injection of fuel allows a higher compression ratio than on a turbocharged engine with conventional manifold injection. This increases the efficiency of the engine accordingly, providing more power on less fuel.

Another important factor contributing to such greater fuel economy is double- VANOS infinite camshaft adjustment typical of BMW power units. An important advantage of double-VANOS is that it helps to develop high torque at low engine speeds for powerful acceleration from the ground up.

Efficiency is enhanced to an even higher level by the volume flow-controlled oil pump, with the oil level being measured by sensors showing the data recorded whenever required in the instrument cluster.

Greater innovation for greater efficiency: volume flow-controlled supply of hydraulic fluid for anti-roll stability.

In addition to all the features mentioned, both the BMW X5 M and the BMW X6 M come with a wide range of BMW ­EfficientDynamics technologies all offered as standard. Brake Energy Regeneration, for example, concentrates the generation of electric current for the on-board network on the car running in overrun and during application of the brakes. This concept of intelligent energy management within the car restricts the conversion of primary energy into electricity to exceptional cases and conditions, with more engine power being provided for extra driving dynamics.

The use of an on-demand electric fuel pump, to mention another example, serves to further reduce the uptake of energy, with the power required by the pressure-controlled pump being reduced by more than 50 per cent under driving conditions in which the engine requires only a small amount of fuel. And last but not least, detachment of the a/c compressor from the belt drive also serves to enhance the vehicles’ efficiency, reducing drag forces from the engine as long as the air conditioning is switched off.

Volume flow-controlled supply of hydraulic fluid exactly as required on the BMW X5 M and the BMW X6 M is a new development serving to enhance the efficiency of the anti-roll stability system featured as standard. An additional valve in the hydraulic pump of the anti-roll stability unit supplies the delivery pistons with exactly the right amount of hydraulic fluid at any given point in time, reducing the uptake of power by the pump by up to 70 per cent when driving straight ahead at a steady speed. And thanks to the precise control technology, the hydraulic pressure required under specific conditions is always provided in good time.

Thanks to the high efficiency of the engine and the wide range of technologies serving to reduce fuel consumption, the BMW X5 M and the BMW X6 M offer not only the highest standard of driving dynamics in the segment of extra-powerful all-wheel-drive cars, but by far also the highest level of efficiency:
litres/100 kilometres, equal to 20.3 mpg imp. Their CO2 rating, in turn, is 325 grams per kilometre.

BMW ­High Precision Injection also has a positive impact on both emissions and the sound of the engine, both models fulfilling the US LEV II emission standard as well as the EU5 classification in Europe.

x5m_e70_gear_lever

M Sports Automatic with electronic gear selector lever and shift paddles on the steering wheel.

Featured for the first time on a BMW M Model, six-speed automatic transmission enhances the high-performance character of the BMW X5 M and the BMW X6 M through the spontaneous gearshift, a direct connection to the engine, and the high standard of gearshift comfort. To achieve extremely short gearshift times the system incorporates an innovative torque-reducing function in the manual mode, switching off individual cylinders by cancelling out the fuel injection and ignition. This allows an extremely fast gearshift and at the same time confirms the particularly sporting character of both models.

BMW’s new M Sports Automatic also incorporates integrated two-damper systems serving to minimise the degree of slip on the converter clutch. Compared with a conventional automatic transmission, the modern torsion damper technology also serves to significantly reduce fuel consumption. To optimise the cooling effect, in turn, the surface of the oil sump made of aluminium again in typical M style comes in a fine ribbed structure.

The new M Sports Automatic is controlled by an electronic gear selector lever on the centre console. Gearshift paddles on the steering wheel made of strong aluminium and again in special M design allow the driver in addition to shift gears manually. In the constellation typical of an M Car, the driver merely pulls the right gearshift paddle to shift up and the left gearshift paddle to shift down.

Apart from the D Mode, the driver also has the choice of the S and M Mode, each offering an even more sporting gearshift set-up. In the M Mode the gear in mesh is kept in position up to maximum engine speed, giving the driver optimum control of the vehicle even under the most dynamic driving conditions. Hence, the transmission does not shift up automatically in this mode.

Moving one of the paddles, the driver is able to shift gears manually at any time in a most spontaneous process. As soon as he does so, the transmission immediately leaves the automatic program and changes automatically to the manual mode. If the driver does not use the paddles again after making such a change, the transmission will move back by itself to the automatic mode after a certain period.

In the M Mode the driver is also able to activate the Launch Control function for maximum acceleration from a standstill. To activate Launch Control, all the driver has to do with the car at a standstill is move the gear selector lever into the M/S lane and call up the Sports Power Mode as well as the M Dynamic Mode or, respectively, the DSC-Off function.

With the transmission in stage M1, the driver then presses down the brake pedal and moves down the gas pedal at least 60 per cent of its full travel in order to set Launch Control to standby. This status is presented by a starter flag symbol in the instrument cluster.

As soon as the driver lets go of the brake pedal, the car will accelerate with full power in genuine racing style. In the process M Sports Automatic automatically shifts gears at the ideal point, with the fastest possible shift times and optimum slip control. Then, taking back the gas pedal, the driver is able to terminate the Launch Control process whenever he wishes.



Last Updated on Saturday, 01 May 2010 18:02  
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