BMW M5 Drive system: Superior power, Supreme efficiency.







Published by Gerald Ferreira Date: February 1, 2012
Categories: BMW, BMW M5

  • High-revving V8 engine with M TwinPower Turbo including cross-bank exhaust manifolds.
  • Maximum output: 412 kW, peak torque: 680 Newton metres; most powerful engine in the M line-up, fuel consumption more than 30 per cent lower than its predecessor.
  • Seven-speed M DCT Drivelogic with three shift programs each for manual and automated modes.

2012 BMW M5

The new BMW M5 adds a fresh, contemporary and fascinating angle to a variety of distinctive features. This applies to both a vehicle concept now in its fifth generation and the car’s engine technology. For the first time, a BMW M5 has a turbocharged engine to thank for its outstanding dynamics.

The high-revving V8 unit with M TwinPower Turbo technology lends a whole new intensity to the powerful thrust sustained into the higher rev ranges for which M cars are renowned. The 4.4-litre engine develops top output of 412 kW at 6,000 – 7,000 rpm, while its maximum torque of 680 Newton metres is on tap between 1,500 and 5,750 rpm. The rev limiter intervenes at 7,200 rpm. The rev band, which offers extremely dynamic acceleration between the arrival of peak torque and the availability of maximum output, is therefore almost three times as wide as that of the predecessor unit.

The drive unit in the new BMW M5 mobilises the highest output ever generated by a BMW M car, and at the same time provides the most efficient balance yet between performance and fuel consumption. The new engine produces around 10 per cent higher output than its predecessor and torque is up by over 30 per cent. Fuel consumption and CO2 emissions, meanwhile, have been cut by more than 30 per cent. This progress in terms of both driving dynamics and efficiency marks the new BMW M5 out as an extremely pioneering interpretation of a premium high-performance sedan.

The driver can use a button on the centre console to adjust the engine’s performance characteristics to the demands of the situation and to individual preferences. “Efficient”, “Sport” and “Sport Plus” modes are available.

Every detail of the engine powering the new BMW M5 has been designed to provide outstanding performance and withstand the pressures generated in the process. For example, a dynamically optimised wet sump oil supply ensures that engine lubrication continues at full effectiveness even under extreme longitudinal and lateral acceleration. The engine also boasts a bespoke cooling system with one high-temperature and one low-temperature circuit.

BMW M5

Racing know-how and unparalleled development expertise: the ideal basis for maximum output and unbeatable efficiency.

The M TwinPower Turbo package of technology developed for the engine powering the new BMW M5 combines design features derived directly from motor racing with innovations spawned by the rigorous implementation of the Efficient Dynamics strategy. It comprises a turbocharging system based on the Twin Scroll Twin Turbo principle, including cross-bank exhaust manifolds, High Precision Petrol Direct Injection and VALVETRONIC variable valve control.

This is a combination without parallel worldwide and produces the suitably exclusive performance characteristics you would expect from a BMW M car. The experience is defined by instantaneous responses and extremely impressive torque developed from extremely low revs and maintained into the higher reaches of the engine speed range.

Concentrated power: turbochargers positioned in the V-shaped space between the cylinders, cross-bank exhaust manifold.

The two turbochargers of the eight-cylinder engine are accommodated, along with the catalytic converters, in the V-shaped space between the cylinder banks, which are positioned at a 90-degree angle to one another. This arrangement produces an extremely compact construction and allows model-specific positioning of the intake and exhaust ducts. Their reduced pipe length and larger cross section minimise the pressure losses on the exhaust side of the engine. There is also a smaller distance between the combustion chambers and the catalytic converters, which helps the “cats” reach their optimum operating temperature soon after the engine has started.

BMW’s patented and globally unique cross-bank exhaust manifold ensures additional optimisation of the gas flow on the way to the two twin-scroll turbochargers. It is made up of four separate exhaust ducts, which are connected with the exhaust ports of two combustion chambers – one on the left-hand cylinder bank and one on the right. Identical pipe lengths and a combustion chamber arrangement mirroring the firing sequence ensure the gas flows through the exhaust ducts at an even rhythm. In each case, two of the four exhaust gas ducts supply one of the two turbos, having been channelled together shortly before they reach the turbine. The result is a consistent level of pressure acting on the two turbochargers, without any kind of counter-flow. This ensures the turbines respond extremely rapidly and charge pressure remains constant.

Effective dethrottling on both the intake and the exhaust side of the engine allows the instantaneous responses typical of M models.

The turbochargers developed specially for the engine powering the new BMW M5 stand out with their particularly high level of compressor and turbine efficiency, and deliver maximum charge pressure of 1.5 bar. Their innovative construction principle uses the potential of turbocharging to deliver an efficient output boost of unprecedented potency. The arrangement of the turbochargers allows the air supply pipes to be kept extremely short. The result is effective dethrottling on both the intake and exhaust side of the engine, which significantly enhances the engine’s responsiveness and fuel economy. The latest version of M TwinPower Turbo technology provides a level of responsiveness, intensity and smoothness in its power delivery unmatched in the segment. In characteristic M engine style, the driver can call on the full consignment of torque with a minimal nudge of the accelerator and as soon as the engine has edged above idle speed.

The engine’s intoxicating thrust gives the new BMW M5 impressive acceleration. The sprint from rest to the 100 km/h mark is all over in 4.4 seconds, and from that point progress continues with barely any let-up. Indeed, the M5 needs just 13.0 seconds to race from 0–200 km/h. Maximum speed is electronically restricted to 250 km/h; if the optional Driver’s Package is specified, this limit is raised to 305 km/h.

The construction principle of M TwinPower Turbo technology also shapes the development of the V8 engine’s soundtrack. The concept of cross-bank exhaust manifolds plays a key role in delivering a multilayered collage of sound. The twin-tailpipe exhaust system of the new BMW M5 runs largely in a straight line and has a large cross section. The two exhaust gas ducts each feed into a single muffler, from which the customary M twin tailpipes jut out through the far left- and right-hand sides of the rear apron.

Direct injection system uses new type of injectors to ensure precise fuel supply.

The engine developed for the new BMW M5 combines its outstanding power development with an unsurpassed level of efficiency in this output class. Credit for the progress made in this area should go to the other components of the M TwinPower Turbo technology package. High Precision Petrol Direct Injection ensures an extremely precise supply of fuel to the combustion chambers. Injectors positioned centrally between the valves within immediate range of the spark plugs spray the mixture into the combustion chambers with a maximum pressure of 200 bar, providing smooth and clean combustion.

Innovative solenoid valve injectors in the new BMW M5 engine use multiple injections to achieve an extremely precise mixture preparation. Plus, the cooling effect of the direct injections enables an extraordinarily high compression ratio for a turbocharged engine, which further increases the efficiency of the V8 engine.

VALVETRONIC gives an additional boost to responsiveness and efficiency.

The M TwinPower technology of the new eight-cylinder engine also includes VALVETRONIC fully variable valve control. This system controls the amount of lift of the intake valves. Throttle losses in the gas cycle are therefore minimised, which has a positive impact on both the efficiency of the powerplant and its torque development. The integration of VALVETRONIC therefore sharpens both the responses and efficiency of the V8 engine in the new BMW M5.

Double-Vanos fully variable camshaft control plays its part both in optimising the engine’s efficiency and generating high torque at low engine revs. In addition, the volume-controlled oil pump and a range of other Efficient Dynamics measures deliver an extra boost to efficiency. The new BMW M5 is fitted as standard with Brake Energy Regeneration and an Auto Start-Stop function, which automatically switches off the engine when the car comes to a halt at junctions or in a traffic jam. The extensive use of efficiency-enhancing technology produces fuel consumption and emissions values unmatched in this output class. The new BMW M5 records average fuel consumption in the EU test cycle of 9.9 litres per 100 kilometres and CO2 emissions of 232 grams per kilometre. In conjunction with a fuel tank expanded to 80 litres, this gives the new M5 a 50 per cent increase in range over its predecessor – and even greater long-distance touring capability as a result.

Designed to deliver maximum performance: dynamically-optimised oil supply, exceptionally efficient cooling system.

The engine powering the new BMW M5 boasts a dynamically optimised wet sump oil supply designed to work under top-end longitudinal and lateral acceleration. This ensures optimum engine lubrication is maintained under extremely dynamic acceleration, braking and cornering. The model-specific geometry of the oil sump includes overflow barriers, which reduce the effect of the centrifugal forces on oil distribution, and precisely defined return channels. The specially developed system also has an optimised oil extraction position and an additional return pump. The wet sump lubrication of the new BMW M5 guarantees reliable oil supply in any driving situation and is also much lighter than a dry sump equivalent.

The cooling system for the new BMW M5 is likewise based on a bespoke concept designed to withstand extreme conditions. It comprises one high-temperature and one low-temperature circuit and includes a pair of electric water pumps with a coast-down function to ensure the cooling effect continues after the engine has been switched off. In all, the system uses ten cooling units for the engine, engine oil, transmission oil, turbocharger and charge air, and to maintain the temperature required by the power steering fluid and engine management unit. Among the other features specific to the M5 is the parallel intercooler supply; indirect charge air cooling using a water circuit further sharpens the responses of the turbochargers.

High performance applies to power transfer as well: the seven-speed M Double Clutch Transmission with Drivelogic.

The new BMW M5 is kitted out with a seven-speed double-clutch transmission to ensure that the transfer of engine output to the rear wheels serves up the time-honoured M experience. The M DCT Drivelogic system developed specially for the M5 has been tuned precisely to the performance characteristics of the V8 engine. Both in automated mode (D) and manual (S) it delivers exceptionally fast and clean gear changes. The system’s control concept follows similar lines to the sequential M transmission in the predecessor car. Again, no clutch pedal is required for manual gearshift, and the driver can keep his foot on the accelerator during gear changes. The driver uses the model-specific M gear selector to choose between D and S mode, and to engage reverse. The transmission offers a sequential shift pattern for the manual gearshift mode. Alternatively, the driver can also change gears manually using the standard-fitted shift paddles on the steering wheel – the right-hand paddle for upshifts, the left-hand paddle for downshifts. Comfort is further enhanced by the new Low Speed Assistance function, which keeps the car moving at minimal speed through stop-start traffic with a light nudge of the accelerator pedal.

M DCT Drivelogic offers three shift programs in both automated and manual mode. The driver selects his desired mode using the rocker switch positioned immediately behind the shift lever on the centre console. The D1 program is selected automatically when the engine is started, tailoring gear selection to deliver the most efficient possible driving style. D2 mode supports laid-back cruising with gear changes carried out according to engine revs and load. And, to promote a sporty driving style laced with dynamic acceleration, shift times in D3 mode are set up to delay gear changes until the engine has climbed higher up the rev range.

The driver can also adapt the shift characteristics to his requirements in manual mode. S1 mode generates extremely comfortable and jolt-free gear changes. In S2 the gear changes are completed noticeably faster and accompanied by significant shift jolts at higher revs. And S3 is the one to choose for maximum dynamics; it enables even sportier gear changes and also brings the Launch Control function into play.

When the stability control system is switched off, Launch Control allows the driver to achieve the maximum acceleration force possible from a standstill – as permitted by the condition of the road – by pressing the accelerator down with maximum force. Each gear change takes place automatically and at the optimum engine speed.

Read more about BMW