One of the most anticipated engines of the 21st Century is about to reveal all of its secrets. The engine that will power the new BMW M3 (more here), it has very big shoes to fill. The sonorous, muscular yet rev-happy inline six that saw out the E46 generation fast coupe is no more, replaced by this 4.0-litre, 309kW V8.
With its roots firmly in the M5 development shed, the new V8 has a redline of 8300rpm -- a figure some sub-2.0-litre fours cannot manage. To say it's a technical tour de force is probably superfluous.
Rather than trawl through the substantial literature BMW has provided on the new engine and its associated systems, we thought just this once we'd let the manufacturer do the talking. Thus here goes… BMW's own words on the new M3 V8…
More in Every Respect: The new V8 Power Unit for the BMW M3
Its name alone spells out the epitome of ultimate driving pleasure: the BMW M3. And now the new version of BMW M GmbH's most successful high-performance sports car bears out this claim once again, at the same time providing a thrilling answer to the question asked by so many sports car fans around the world whether a further improvement is still possible at all.
And the answer is yes -- for the new BMW M3 offers more in every respect.
The benchmark the new power unit was required to exceed could hardly have been greater: BMW's 3.2-litre straight-six has gained fame and admiration the world over, receiving a long list of awards and prizes. Acknowledged several times as the "Engine of the Year" and developing a supreme 252kW/343hp in its last version, this power unit made the BMW M3 not only the ultimate performer in the segment of high-performance sports cars, but also a genuine best seller.
The fact still remains, however, that everything has its time. And now the time has come for the six-cylinder to bow out and leave the stage. The time has come for the advent of the new V8 in the new BMW M3.
The specifications of this new high-performance power unit alone clearly confirm the enormous progress this engine has to offer. Engine displacement is 3999 cc, maximum output is 309kW/420hp. Peak torque of 400Nm is just as impressive as the top engine speed of 8300rpm. So clearly, the new BMW M3 is striking out for the top right from the start through its thrilling performance.
>> Ideal dimensions for performance at its best.
Displacing 500cc per cylinder, the new V8 power unit meets the ideal concept of the most demanding engine designers right from the start through its engine dimensions alone. And the other design criteria -- all the way from the engine's dimensions and filling capacities through the number of components to the weight of the engine --likewise represent the very best achievable today.
Over and above these qualities, the new eight-cylinder offers all the typical M-tuned features of BMW's regular production cars such as double-VANOS, individual throttle butterflies, and high-performance engine electronics. At the same time the number of cylinders, the M high-speed engine concept, and the low weight of the engine clearly prove that the responsible engineers, in creating this power unit, were inspired and guided by the eight-cylinder featured in the BMW Sauber F1. For the new engine has many features in common with the latest power unit highlighted by BMW in Formula 1, with various technological concepts and principles, production processes and materials carried over from the Formula 1 engine to the drivetrain of the new BMW M3.
In terms of specific output, the new V8 significantly exceeds the benchmark of 100hp per litre acknowledged as a convincing sign of sporting power and performance. But even so, power is not everything. Rather, the dynamic driving experience provided by a car depends to a great extent on its acceleration and handling, resulting, not least, from the weight of the car and the actual thrust of the engine. The thrust or traction acting on the drive wheels, in turn, results from engine torque and the overall transmission ratio.
The M high-speed engine concept allows optimum transmission and final drive ratios further enhancing the impressive thrust and power of the engine. Indeed, BMW M's engineers have found a new dimension in developing the engine of the new BMW M3, with the eight-cylinder achieving maximum engine speed of 8300 rpm.
The second factor crucial to thrust and performance on the road, engine torque, amounts to a mighty 400Nm on the new V8 power unit. And about 85 per cent of the engine's maximum torque is available throughout the enormous engine speed range of 6500rpm, with 340Nm available from just 2000rpm.
>> High engine speed, low weight
Mass (which, ultimately, means weight) is bad for acceleration -- it makes any physical body seeking to accelerate slower and more sluggish. Precisely this is why BMW's new V8, weighing a mere 202kg is a genuine lightweight, saving some 15kg versus the six-cylinder power unit in the previous model. In other words, the new engine easily sets off the weight of two extra cylinders. And a further point is that the high-speed engine concept allows a light drivetrain and very short transmission ratios.
>> Engine block straight from BMW's Formula 1 foundry
The engine block of the new eight-cylinder comes straight from BMW's light-alloy foundry in Landshut near Munich, where BMW also builds the engine blocks for the Company's Formula 1 racing cars. The cylinder crankcase, in turn, is made of a special aluminium silicon alloy, conventional cylinder liners being replaced by hard silicon crystals. The iron-coated pistons, finally, run directly in the uncoated, honed cylinder bore.
High engine speeds, compression forces and temperatures cause extreme loads acting on the crankcase. Hence, the crankcase is compact in its dimensions and comes in torsionally resistant bedplate design ensuring very precise crankshaft bearing and running conditions. The relatively short, forged crankshaft is likewise very stiff in terms of its flexural and torsional qualities, but weighs only 20kg.
>> Double-VANOS with low-pressure operation
With its extremely short control times, variable double-VANOS camshaft management perfects the cylinder charge cycle, reducing charge losses and improving engine output torque and response, as well as fuel economy and emission management.
Developed especially for the new eight-cylinder, the M double-VANOS now featured on the new engine requires no more than normal engine oil pressure in order to operate at maximum speed. As a function of load and engine speed, this sophisticated unit consistently sets the optimum valve angle synchronised to the ignition timing and injection volume.
Two volume-flow controlled pendulum slide cell pumps supply the eight-cylinder efficiently with lubricant, consistently delivering exactly the right amount for the engine. Wet sump lubrication optimised for engine dynamics, in turn, ensures appropriate lubrication also in extreme braking manoeuvres.
The entire system features two oil sumps -- a small one in front of the front axle subframe and a larger sump further back. A separate reflow pump, in turn, extracts oil from the front oil sump and pumps it to the sump at the rear.
>> Eight individual throttle butterflies with electronic control
Individual throttle butterflies for each cylinder, a technology commonly used in motorsport, are the ideal solution to give the engine an immediate, direct response at all times. The new power unit in the BMW M3 therefore comes with eight individual throttle butterflies, four on each row of cylinders operated by separate actuators. This high-tech throttle butterfly management is fully electronic and extremely fast, giving the engine a smooth and sensitive response at low engine speeds and an immediate reaction to the driver's commands whenever he wishes to use the full power of the engine.
>> Flow-optimised air intake
To ensure an immediate response and superior dynamics of the engine at all times, the throttle butterflies in the intake manifolds are positioned very close to the intake valves. The specific length and diameter of the intake funnels also benefit the oscillating pipe charge principle. To minimise weight, finally, both the intake funnels and air collector are made of a light composite material with a 30 per cent share of glass-fibre.
>> Innovative exhaust system
Through its design and configuration, the exhaust system for the new V8 power unit optimises the cylinder charge cycle, ensuring an optimum surge of power and torque at all times. And again, this component has been designed and built from the start for consistent lightweight qualities.
The exhaust manifolds are made in an internal high-pressure remoulding process, the desired contours of the stainless-steel pipes being shaped from inside under pressure of up to 800 bar. The result is extremely thin walls measuring just 0.65–1.00mm in thickness, optimising flow conditions with minimum resistance, light weight, and optimum response of the catalytic converters.
>> Even better performance than before: the engine control unit
The engine control unit featured on the V8 has also been upgraded to an even higher standard than before, ensuring optimum coordination of all engine functions. Taking more than 50 input signals, for example, the control unit determines the optimum ignition timing individually for each cylinder and operating stroke, the ideal flow conditions, exactly the right amount of fuel injection, and the optimum injection timing. At the same time the system calculates and sets exactly the right camshaft angles (angle spread), as well as the respective position of the eight individual throttle butterflies. And last but not least, the control unit enhances and masterminds specific BMW M functions such as the clutch, transmission, steering, and brakes.
Yet a further function of the engine control unit is to perform a wide range of on-board diagnostic functions with various diagnostic routines for servicing at the workshop as well as other functions and the efficient management of peripheral units and systems.
>> Ion flow technology
A particular highlight in engine management is ion flow technology detecting any knocking in the engine as well as the risk of misfiring or miscombustion. Contrary to conventional processes and technologies, this function is now performed directly where it counts, that is right there in the combustion chamber itself. To provide this highly efficient control, each cylinder is monitored and controlled via the spark plug to determine any knocking tendency. At the same time the system checks the ignition for smooth and correct operation, and recognises any misfiring.
The spark plug therefore serves as an actuator for the ignition and as a sensor observing the combustion process, distinguishing in this way between miscombustion and misfiring. And through this double function performed by the spark plug, diagnostic requirements in maintaining and servicing the engine are also facilitated.
>> Brake Energy Regeneration
To further enhance the efficiency of the new V8 power unit, Brake Energy Regeneration ensures intelligent engine current management concentrating the generation of electric power for the on-board network on the overrun phases and the application of the brakes. This serves to charge the car's battery without tapping on engine power and, accordingly on the energy contained in the fuel burnt. As long as the engine is running under power, on the other hand, accelerating and pulling the car, the alternator generally remains disconnected.
Apart from particularly efficient generation of electric current, this also helps to provide more drive power when accelerating, making the car even more dynamic and agile on the road.
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