As with the McLaren Formula 1 car, a shift can be actuated either by pulling or by pushing on the rocker. The rocker moves with the steering wheel, rather than being mounted on the steering column, so that if a gearchange is needed while lock is being applied the driver does not have to fumble around to change gear.
The rocker itself incorporates an innovative feature created by McLaren engineers called Pre-Cog. The name stands for pre-cognition, literally `foreknowledge'. The rocker on the 12C has two positions with a slightly different haptic (or feel) for each. The driver applies first pressure to the rocker and it informs the gearbox to get ready to swap ratios, thereby saving time - latency - between the message being sent and the gearbox being primed to act. The second pressure confirms that the gear should be changed and the torque handover is completed in milliseconds.
"What Pre-Cog actually does is initiate the shift process by priming the clutch and torque handover - it takes significant time out of the process," explained Dick Glover, Technical Director McLaren Automotive.
"It's a little bit like the first pressure on a camera shutter button. There's no requirement for the driver to use it but it is more satisfying and engaging if you do. The SSG also promotes seamless shifting in which the driver doesn't have to reduce engine power at all - rather than the gearshift slowing you down, it actually speeds the car up by recovering the energy of the crank spinning as it drops engine speed," he said.
In practice the latency of the shift is virtually zero, the actual gear change time is very fast and the level of impulse can be varied according to the gearbox mode. Considering that McLaren was the first Formula 1 team to introduce seamless shift gearchanges into motor racing, it was a natural step to develop such a bespoke transmission to its sports car project.
Chassis: Proactive Control
The suspension for the McLaren MP4-12C breaks new ground, offering hitherto unseen levels of roll control and grip (an almost flat cornering attitude, depending on the programme selected).
Although such track-like responses would normally imply a rock-hard ride, the 12C delivers compliance and ride comfort more akin to an executive saloon car. The mix of occupant cosseting and sporting potential is truly unique. The 12C offers the driver both class-leading ride comfort and class-leading performance.
The whole chassis package produces not only a unique relationship between ride and handling, but also astonishing lateral grip and outstanding traction. The 12C is poised and balanced whether negotiating high or low speed corners, during direction changes, under heavy or light braking and on tightening or opening corners.
The trick behind blending such opposing objectives lies in the innovative Proactive Chassis Control system, uncompromised geometry, and weight distribution.
The suspension is based on double wishbones with coil springs. The dampers are interconnected hydraulically and provide adaptive responses depending on both road conditions and driver preference.
The Proactive system features adjustable roll control which replaces the mechanical anti-roll bars that have been a standard feature of road cars since time immemorial. It allows the car to maintain precise roll control under heavy cornering while decoupling the suspension in a straight line for excellent wheel articulation and compliance.
There are three suspension modes that are selected on the Active Dynamics Panel. As with the powertrain adjustment, there is a `normal', a `sport' mode and a high performance mode which adjusts numerous parameters in the system.
Not only is the Proactive suspension a unique application that delivers absolute benefits to driver and passenger, but it is also another example of McLaren's drive to achieve all-round performance goals from core engineering targets.