World’s Most Powerful BMW Six-Cylinder Diesel Engine set to arrive in Singapore

[B]World’s most powerful six-cylinder in-line diesel engine:
M Performance TwinPower Turbo with three turbochargers and advanced common-rail injection system for the first time. [/B]

The first of the new BMW M Performance Automobiles – founding a product category focusing on sporty driving pleasure – are powered by a diesel engine. The 3.0-litre six-cylinder in-line unit, whose cover bears the M Performance badge, has all the necessary tools to fulfill the brief handed to the new breed: technology without parallel worldwide, the highest output ever achieved by a BMW diesel engine and outstanding levels of efficiency.

[B]The BMW X5 M50d and BMW X6 M50d:
An imposing presence in both the acceleration and efficiency rankings. [/B]

With its maximum output of 381 hp and peak torque of 740Nm the engine developed for the BMW M Performance Automobiles also brings a level of performance to the two BMW X models which no other diesel-powered car in their segments can match. The BMW X5 M50d accelerates from 0 to 100 km/h in 5.4 seconds, the BMW X6 M50d in just 5.3 seconds, while average fuel consumption in the EU test cycle stands at 7.5 litres/100km for the Sports Activity Vehicle and 7.7 litres/100 km for the Sports Activity Coupé – only slightly above the figures for the existing diesel variants of the two models. CO2 emissions are 199g/km for the BMW X5 M50d and 204 g/km for the BMW X6 M50d.

[B]M Performance TwinPower Turbo Technology:
More pressure, more output, more torque. [/B]

The coordinated interplay of turbochargers of different sizes endows an engine with instantaneous responsiveness at low revs and allows charge pressure to be increased according to need when the engine is placed under greater loads.

The company is set to become the world’s first carmaker to present a diesel engine which expands the principle of multi-stage turbocharging to incorporate a third turbocharger. The engine developed for the BMW M Performance Automobiles will, for the first time, see two comparatively small high-pressure chargers working with a larger low-pressure unit. The integration of an additional high-pressure turbo increases the engine’s capability when it comes to generating charge pressure, a key ingredient in taking the engine’s power output to the next level.

[B]Instantaneous responsiveness and precisely coordinated interplay.[/B]
One of the two small turbos is activated at engine speeds just above idle. Its low moment of inertia allows it to respond without delay to the slightest movements of the accelerator and therefore supply the combustion chambers with compressed air at an early stage. As revs increase, the flow of exhaust gas also reaches the larger turbocharger, which announces its arrival with the engine spinning at just 1,500 rpm. Working together with the small charger, it ensures that the impressive peak torque of 740Nm is generated at this low engine speed and maintained up to 3,000 rpm.

To further increase the performance of the large turbocharger, a greater volume of exhaust gas is required at around 2,700 rpm. If the driver calls up additional power, a vacuum-modulated exhaust flap instantly opens up another supply route, allowing extra exhaust gas to flow past the already active high-pressure charger to the large low-pressure turbo..

In order to ensure that charge pressure is developed as effectively as possible, not to mention efficiently, both the exhaust flow and supply of fresh air to the turbos and the channelling of compressed air into the combustion chambers is regulated with maximum precision. If the large turbocharger is spinning at particularly high speeds, a vacuum regulator opens a wastegate valve to relieve the pressure and so avoid unwanted exhaust backpressure. The supply of fresh air is also controlled according to need by means of pneumatically activated flaps

[B]Detailed optimisation enables higher combustion pressure, increased output and enhanced efficiency. [/B]
The new torquey and high-revving diesel engine also breaks new ground with its specific output of 93.6 kW per litre of displacement. However, the output possible using M Performance TwinPower Turbo technology is generated not in the turbochargers but in the core of the basic engine, which has therefore also been extensively modified. Maximum combustion pressure has risen from the 185 bar of the most powerful diesel engine in the existing BMW line-up to 200 bar.

As part of this development, the crankcase in the new 3.0-litre diesel engine features an innovative tie rod concept for the assembly of the main bearing caps and cylinder head. The sintered main bearing caps are given extra strength by a central screw. Like the crankcase, the cylinder head is also subjected to a special high-pressure compression process. This “HIPen” manufacturing concept sees the aluminium castings heated to solution annealing temperature and the casting pores created during manufacturing welded under high pressure. This process gives the finished component additional strength. A double diagonal bore ensures the interbore bridges have high thermal stability.

The geometry of the crankshaft and connecting rods has been further optimised and they are now made from higher-strength materials. Added to which, hub bushings and bowl rim remelting enhance the effect of the increase in piston compression height.


Both the BMW X6 M50d and BMW X5 M50d are slated to arrive in Singapore later in November 2012.
[B][/B]

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