The shocks have a wider spread of damping than before, the coil springs and anti-roll bars are changed, and the rear wheels are a half-inch wider. Electronically adjustable dampers (PASM) are now standard on the Carrera. On the basic Carrera and Carrera S, the chassis undergoes a number of tuning changes. The powertrain and the chassis go into their most aggressive modes for 20 seconds of maximum acceleration.

Hit it and the car gives you the full Busey. PDK cars with Sport Chrono also get a small black button in the middle of the mode dial called the Sport Response button. The effect is more exhaust gas blowing over the turbine before boost is called for, which reduces turbo lag. Sport and Sport Plus modes make the engine slightly more reactive by “priming the pump” through changes in camshaft phasing and retarding the ignition timing. Sport Chrono also adds the launch-control capability to the PDK automatic. PDK-equipped 911s switch to a more aggressive transmission program that automatically downshifts upon hard braking and holds gears longer. Manual-transmission versions gain automatic rev matching in Sport and Sport Plus. Cars with Sport exhaust get louder in Sport and Sport Plus mode. Switching to Sport or Sport Plus tightens the electronically adjustable shocks.

What the knob changes depends on the optional extras on your car. Turning it toggles among Individual, Normal, Sport, and Sport Plus. Opt for the Sport Chrono package and, in addition to a snazzy dash-mounted stopwatch, you get active engine mounts that tighten to minimize the effect of a rollicking engine as well as a mode-selector dial on the steering wheel.

Sport chrono package