The new Mercedes-Benz E 63 AMG: Chassis and braking system - Agile, dynamic, exclusive
High levels of driving dynamics and inspirational agility combined with the comfort on long journeys typical of Mercedes – these are the strengths of the E 63 AMG. They owe their origins to the exclusive combination of the AMG RIDE CONTROL sports suspension, electromechanical steering and AMG high-performance braking system.
Compared with the series production models of the E-Class, the E 63 AMG features the highly-variable AMG RIDE CONTROL sports suspension with electronically controlled damping system. A steel suspension is used at the front, and an all-air suspension system at the rear. This solution guarantees a sensitive response from the front springs while the vehicle is kept at a constant height thanks to the automatic level control system – irrespective of the load. The independent three-link front suspension has a 56 mm wider track. In conjunction with new hub carriers for more negative camber at the front, this provides much more grip when taking bends at high speed.
New axle components and more direct steering
The high-grade axle components, produced for the most part from lightweight aluminium, are further evidence of the painstakingly redesigned AMG RIDE CONTROL sports suspension. New steering knuckles, wishbones, torque strut bearings and head bearings at the front provide extra stability and improved road contact. A weight-optimised, thicker tubular stabiliser reduces body roll on fast S-shaped bends. The rear suspension has also been substantially reworked in the interests of enhanced handling stability: new track rods, push-pull rods, more negative camber and far more rigid mountings for the subframe – on which the rear axle is mounted – translate into enhanced lateral dynamics. The AMG-specific kinematics and the new elastokinematics on both axles also noticeably increase precision during cornering.
A synthesis of maximum agility and optimum ride comfort
Another feature of the AMG RIDE CONTROL sports suspension is the electronically controlled damping system: the system varies the damping characteristics instantly according to the driving situation, road speed and load status, automatically reducing the roll angle of the body. For the driver this means instant, continuously variable adjustment between the greatest possible agility and optimum ride comfort – depending on the driving style and route. The damping can also be individually adjusted by pressing the appropriate button in the AMG DRIVE UNIT. A push of the button labelled with a shock absorber is all it takes for the electronics to switch from "Comfort" to "Sport" or "Sport plus." The selected mode is displayed in the AMG instrument cluster.
"Comfort" delivers a sensitive response with soft damping characteristics, while the shock absorber response is an average 40 percent firmer in "Sport". "Sport plus" is ideal for challenging laps on a racetrack: in addition to the higher damping force, this mode comes with specific control algorithms that have been tailor-made for a decidedly sporty driving style on level road surfaces.
Eleven sensors for electronic damper control
The electronic damper control utilises four sensors to permanently monitor the drive and brake torque along with steering angle and lateral acceleration. Four position sensors are also used to determine the ride height and to ascertain the direction of motion. Three acceleration sensors help identify the absolute body roll. Powerful control electronics that interact constantly with the engine and transmission control units instantly adjust the forces at the four shock absorbers. The driving dynamics of the E 63 AMG can even be enhanced further ex works: available from the AMG Performance Studio as an exclusive optional extra is the AMG RIDE CONTROL Performance suspension, which features even stiffer damping.
New, more direct electromechanical steering ratio
This is complemented by the newly developed electromechanical AMG sports parameter steering: with a steering ratio (14:1) which is 22 percent more direct than that of other E-Class models, and in conjunction with the variable power assistance which adapts according to the suspension mode, it provides for decidedly agile handling when cornering. In addition, the electromechanical AMG sports parameter steering also makes an important contribution to efficiency, since the steering assist function only requires power when the driver actually steers. Compared with the previous model with regular hydraulic power steering, this enables further potential fuel savings to be achieved.
In the new steering system the steering gear and the supporting servo-motor form a single compact unit and are mounted as previously on an extremely rigid and low-weight integral support frame, made of high-strength steel, which is positioned in front of the wheel's centre line. The high-performance control unit processes a variety of parameters captured by the sensors – including vehicle speed, steering angle, steering angle speed, lateral acceleration and also understeer/oversteer characteristics – and in a split second calculates the forces which the driver needs to input into the steering in different driving situations – from parking to high-speed motorway driving. Active damping enhances the feeling of safety when driving straight ahead at high speed.
AMG-specific solutions for enhanced steering precision and driving dynamics
An AMG-specific solution has been implemented in the form of the fixed, programmed power assistance characteristics. In suspension mode "C", the AMG sports parameter steering has a comfortable feel, providing a higher level of steering assistance. In "S+" mode, on the other hand, the driver will discern reduced steering assistance – which tends to result in a better road feel. This in turn results in enhanced response and steering precision. Another AMG exclusive is the interaction between the new steering and the 3-stage ESP®: the driver will feel if the vehicle starts to understeer thanks to a defined superposition of the steering moment earlier than with a regular power steering system. In "SPORT" handling mode and "ESP OFF", the special control algorithm helps the driver to achieve a cleaner side-slip angle.
In addition to more precise steering and a more comfortable feel at the wheel, the new electric power steering offers a range of additional advantages. Power assistance remains available when the engine is stationary, for example – whereby an algorithm ensures that the combustion engine is not prompted to start up in ECO start/stop mode when the driver is merely moving the steering wheel while the vehicle is at a standstill. In addition, the electromechanical steering compensates for road distortions, thereby providing the driver with a more comfortable driving experience by balancing the steering moments when on a road which slopes off to one side, for example.
3-stage ESP® system with "SPORT" handling mode
The 3-stage ESP® is also consistently tailored to the superb dynamic qualities of the E 63 AMG: the Electronic Stability Program supports three individual control strategies at the push of a button: the ESP® button in the AMG DRIVE UNIT allows the driver to choose between "ESP ON", "SPORT" handling mode, and "ESP OFF" – with the currently active mode shown in the display of the AMG instrument cluster. In "ESP ON", the onset of handling instability leads to braking intervention at one or more of the wheels, accompanied by a reduction in engine torque.
Briefly pressing the ESP® button activates "SPORT" handling mode. In this mode the braking intervention to counter oversteer or understeer, as well as the accompanying reduction in engine torque, allows a higher dynamic threshold and, for instance, corresponding drift angles – the result for the driver is significantly enhanced driving enjoyment. Operating the brake pedal restores all the normal ESP® functions. Prolonged pressure on the ESP® button activates "ESP OFF". With this, the engine torque is no longer reduced to control the driving dynamics – and driving enjoyment is therefore increased even further. "ESP OFF" should only be used by experienced drivers on dedicated racetracks. In this mode too, ESP® is available by operating the
The system's traction logic is active in all three ESP® modes. If one of the drive wheels starts to spin, specific brake pressure is applied to virtually create the effect of a mechanical differential lock. This means that the engine power is transferred to the road even more effectively. To improve traction, particularly when on the race track, a rear axle locking differential with 40 percent locking action is available as an option from the AMG Performance Studio.
New ceramic composite high-performance braking system available as an option
As of course with all AMG high-performance cars, the new E 63 AMG also comes with an ultra-powerful braking system. Ventilated and perforated brake discs with a generous 360-millimetre diameter are fitted front and rear. Because of the special stresses they face, the front discs feature composite technology that has been tried and tested in motor racing to help offset the temperature peaks more effectively. Grey-painted brake callipers with white AMG lettering and six-piston (front) and four-piston technology (rear) provide responsive, fade-resistant deceleration and extremely short stopping distances.
AMG ceramic composite high-performance brakes are available as an option and are instantly recognisable thanks to the "AMG Carbon Ceramic" logo on the specially painted brake callipers. Thanks to the exclusive materials and production technology used to manufacture the discs from carbon-fibre-reinforced ceramic in a vacuum at 1700 degrees Celsius, the ceramic discs are much harder. This not only increases the service life many times over compared with a grey cast iron disc, but also their resistance to extreme loads and heat. The result is extremely short stopping distances, an exact pressure point and much higher fade resistance even under extreme operating conditions. The larger ceramic discs – front: 402 x 39 millimetres; rear: 360 x 32 millimetres – feature a composite design all round, are ventilated and perforated, and also connected with a floating radial mount to an aluminium bowl.
Compared with the conventional composite brake discs, the ceramic brake discs are around 40 percent lighter. The further reduction in unsprung masses not only boosts driving dynamics and agility but also improves steering response as well as ride comfort and contact characteristics. Six-piston fixed callipers are fitted at the front with a brake lining surface of 2 x 154 cm2; four-piston fixed callipers with a brake lining surface of 2 x 73 cm2 are used at the rear.
Overview of brake data:
Numerous functions of the high-performance braking system enhance comfort and safety. Take the practical HOLD function: if the E 63 AMG has come to a stop, the driver simply needs to press the brake pedal a little bit firmer. The vehicle is now held by the brake – even if the driver takes their foot off the brake pedal. This prevents the vehicle from unintentionally rolling forward in stop-and-go traffic or inadvertently rolling back on an uphill slope. The HOLD function is automatically disengaged once the vehicle is driven forward. Another useful feature comes in the shape of the hill-start assist. If the sensor technology detects that the driver has stopped on an incline, the brake pressure is automatically maintained constant for a short period. This means the vehicle will not roll back and the driver has sufficient time to switch from the brake to the accelerator pedal without having to use the parking brake.
When the driver suddenly switches from the accelerator to the brake pedal prior to emergency braking, the braking system increases the pressure in the brake lines and applies the pads to the brake discs, so that they can grip instantly with full force when the brake pedal is pressed. The system supports the standard Brake Assist by means of this 'priming'. Further standard features include the brake-drying function, which uses brief braking impulses to ensure that the film of water on the brake discs is removed in the wet, thus considerably improving the responsiveness of the brakes.
Weight-optimised "Flow Forming" AMG light-alloy wheels
The newly developed AMG 10-spoke light-alloy wheels make a significant contribution to the dynamic handling of the E 63 AMG. As on the SLS AMG, they are produced by the new "flow forming" process. During this production process, hot forming in the area of the rim base makes for a denser material structure, thereby improving long-term durability. This also means that lower wall thicknesses can be achieved. The weight saving of up to 0.8 kg per wheel compared to conventional light-alloy wheels reduces the unsprung masses, further improving the handling dynamics and suspension comfort.
As standard the E 63 AMG comes with titanium grey-painted, high-sheen wheels featuring a new 10-spoke design. The 9.0 x 18 format front wheels are fitted with 255/40 R 18-size tyres, while the 9.5 x 18 format rear wheels come with 285/35 R 18-size tyres.
Source: Daimler AG
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