Engine and power transmission: The perfect sports car drive system

Nov 18, 2011
  • Dynamic: AMG 6.3-litre V8 engine producing 380 kW (517 hp)
  • Pure excitement: lively, powerful and responsive
  • Technology transfer: engine with high-tech components from the SLS AMG
  • Variable: AMG SPEEDSHIFT MCT 7-speed sports transmission
High levels of performance and torque, distinctive V8 sound, powerful traction and exhilarating response: the AMG 6.3-litre V8 engine makes the perfect drive system for the C 63 AMG Coupé Black Series. An output of 380 kW (517 hp) and torque of 620 Nm make the new sports car the most powerful C-Class of all time. The performance figures speak for themselves: zero to 100 km/h in 4.2 seconds, and a top speed of 300 km/h (electronically limited). Developed by Mercedes-AMG and presented in 2005, the V8 engine designated as the M156 impresses with every kilometre: its agility and response help to ensure high levels of emotive appeal, while the exciting power delivery guarantees dynamic driving pleasure.
Consistent technology transfer from the SLS AMG
A glimpse under the distinctive bonnet reveals that the C 63 AMG Coupé Black Series makes use of a special variant of the AMG 6.3-litre V8 engine: the black engine plate on the variable intake manifold makes reference to the technology transfer from the SLS AMG. The M 156 features the forged pistons, connecting rods and lightweight crankshaft from the gullwing model. The resulting lower engine weight, which has been reduced by four kilograms, in turn reduces mass inertia, and as a result the eight-cylinder engine reacts more spontaneously to accelerator pedal movements and provides exciting levels of response. A new engine control unit rounds off the list of in-engine measures.
The oil cooling too has been optimised with components from the gullwing model. The cooling surface, which has been enlarged by 50%, compensates for temperature peaks. The result is increased fatigue strength in demanding race track conditions.
Key data at a glance:
C 63 AMG Coupé Black Series
Cylinder arrangement/number
Cylinder angle
Valves per cylinder
6208 cc
Bore x stroke
102.2 x 94.6 mm
Cylinder spacing
109 mm
Compression ratio
380 kW (517 hp) at 6800 rpm
Output per litre
61.2 kW (83.3 hp)
Max. torque
620 Nm at 5200 rpm
Torque per litre
99.8 Nm
Maximum engine speed
7200 rpm
Engine weight (dry)
195 kg
Fuel consumption, NEDC combined
12.2 l/100 km
CO2 emissions
286 g/km
Acceleration 0 - 100 km/h
4.2 s
Top speed
300 km/h*
* electronically limited
Further attributes of the AMG 6.3-litre V8 engine:
  • Torsionally stiff full aluminium crankcase in closed deck design,
    with a bedplate construction for the lower crankcase section
  • Integral oil windage tray to help reduce foaming of the engine oil
  • Finely balanced, lightweight forged steel crankshaft
  • Forged crack connecting rods in lightweight construction
  • Forged pistons made from a highly durable, ultra heat-resistant alloy
  • Piston crowns cooled through pressure-controlled oil-spray nozzles
  • Magnesium variable intake manifold with two integral throttle valves to give a steep torque curve and excellent performance
  • Vertical intake and exhaust ducts
  • Four-valve-per-cylinder design, valve control linkage using bucket tappets
  • Continuous camshaft adjustment on the intake and exhaust sides
  • Engine cooling based on the cross-flow principle
  • Variable control of the coolant temperature
  • Highly effective exhaust gas emission control meeting the EU5 emissions standards
  • Engine produced by craftsmen with traditional skills and values whose philosophy is "One man, one engine"
Characteristic AMG V8 sound arouses passions
A major factor in its overall attractiveness is the role played by the typically AMG sound released from the AMG sports exhaust system. The emotionally appealing V8 sound arouses pure passion in the driver. The two chrome twin tailpipes with angular cross-section already hint at the acoustic qualities and power of the Black Series engine even when the vehicle is at a standstill.
The twin-wire-arc-sprayed (TWAS) coating on the cylinder walls – developed by AMG and used since 2005 – produces outstanding low-friction characteristics while reducing fuel consumption. The technology, now referred to as NANOSLIDE has also come into play in Mercedes diesel engines. The electronically controlled fuel supply is also highly effective: depending on the power requirements and outside temperature, the system operates at a demand-actuated fuel pressure of between 3.6 and 4.5 bar and is regulated practically instantaneously. The engine management system translates the command from the accelerator within milliseconds into the corresponding fuel pressure setting. Such control ensures rapid vehicle response and sporty acceleration across all load ranges and at all engine speeds.
6.3-litre V8 engine – the most successful AMG engine
The M156 AMG 6.3-litre V8 engine made its debut back in 2005 and is still viewed as one of the best-performing and torquey eight-cylinder naturally-aspirated engines in series production in the world today. With more than 71,000 units built, it is the all-time leader as far as AMG engine production is concerned. The high-revving engine received two awards for best engine at the prestigious "International Engine of the Year Awards" in 2009 and 2010: it secured first place well ahead of all other entrants for the "Best Performance Engine" and "Above 4 litres" classes.
AMG SPEEDSHIFT MCT 7-speed sports transmission
In addition to the engine, the power transmission also makes a significant contribution to the pure excitement delivered by the vehicle: as in the other variants of the Mercedes-Benz C 63 AMG, the most powerful C-Class of all time also makes use of the AMG SPEEDSHIFT MCT 7-speed sports transmission. Its strengths include the combination of the sporty and agile feedback of a manual transmission with the maximum comfort of an automatic. The innovative power transmission has seven gears and provides a high degree of variability: four transmission modes as well as double-declutching and RACE START functions enable the driving style to be matched specifically to the respective conditions.
The MCT transmission: lightweight construction and high-tech interior
MCT stands for Multi-Clutch Technology, indicating that gear-changing is executed by clutch elements alone. A compact wet start-up clutch, which runs in an oil bath, replaces the conventional torque converter. Thanks to its low rotational inertia, the transmission responds instantaneously and dynamically without the losses typical of a torque converter transmission – thereby helping to save fuel. Used exclusively at AMG, the sports transmission also impresses with its low weight of just 80 kilograms, which has been made possible through the use of lightweight magnesium for the transmission housing. Vibrations are effectively eliminated by a two-stage torsion damper, with resulting benefits in perceived passenger comfort.
Drive modes "S", "S+" and "M" for driving pleasure and dynamism
When moving off in "C" (Controlled Efficiency) transmission mode, the MCT transmission always selects second gear and shifts decidedly early to the higher gears if the driving style permits. When driving in town, the C 63 AMG Coupé Black Series often engages sixth gear, for example – thus improving both fuel consumption and noise levels. Controlled Efficiency also means convenient gearshifts and a "soft" accelerator response set-up for smooth movement.
The engine and transmission take on a much more agile character in the "S" (Sport) than in the "C" mode. Accelerator pedal movements trigger a more direct traction response, making the downshifts more spontaneous. The engine speed is allowed to reach a higher level in each gear, while the gearshifts are around 25 percent faster. Turning the rotary switch in the centre console a notch further to the right activates "S+" mode. Sport plus shifts the gears another 25 percent faster than in "S". The same applies to the manual shift mode "M". In "S+" and "M" modes, gearshifts at full throttle take just 100 milliseconds.
The engine management system partially suppresses cylinders in "S", "S+" and "M" modes: precisely interrupting ignition and injection under full load for brief periods leads to even faster gearshifts than before. The highly emotional vocals are an appealing side effect of this lightning-fast process.
Double-declutching function, which increases driving enjoyment and safety
Ultra-fast, spontaneous multiple downshifts are another forte of the AMG SPEEDSHIFT MCT 7-speed sports transmission. The driver, for instance, can use kickdown to change directly from seventh gear down to fourth or from fifth to second. In the Sport, Sport plus and Manual modes the automatic double-declutching function is active. Every manual or automatic downshift is accompanied by precisely metered double-declutching – from "S" through "S+" to "M" - with increasing intensity. And this not only adds to the emotional experience: the load-free downshift reduces load-change reactions, which pays dividends – particularly when braking into a bend on the racetrack – and also enhances safety in the wet or on ice.
In manual "M" mode, the driver additionally benefits from the high torque of the V8 engine: the transmission remains in the gear selected; there is no automatic downshift under full load and kickdown. Moreover, the AMG MCT sports transmission does not perform an automatic upshift in manual mode when the rev limit is reached. In "M" mode the central display in the AMG instrument cluster displays the current gear and alerts the driver to the need for an upshift by means of a visual sign: the display colour changes to "Red" and the message "Up" appears. This means that the driver can make better use of the superior performance potential.
RACE START function: for the ultimate acceleration experience
The driver can change gears using the selector lever and the shift paddles on the steering wheel. To the left of the selector lever is the electronic rotary switch for the selection of one of the four drive programs, including activating the RACE START function. In order to activate it, the driver needs to activate the ESP® SPORT Handling mode and press the brake pedal with his left foot while the vehicle is at a standstill. Having preselected the Race Start program using the rotary switch, a confirmation message comes up on the AMG central display. The driver then simply needs to confirm the function by pulling the “Up” shift paddle once, fully depressing the accelerator and taking his foot off the brake. The optimum start-up engine speed is set fully automatically and the vehicle accelerates away with flawless traction – all the way up to top speed, if so required. The driver does not need to shift gear manually; the AMG transmission changes gear autonomously.
The powerful electronic transmission control unit and the integrated 80 MHz processor ensure spontaneous downshifts at the same time – say when approaching traffic lights or if the driver suddenly needs power for dynamic acceleration.