Porsche Stability Management (PSM)
Porsche Stability Management (PSM)
Like the previous models, the new 911 models come as standard with Porsche Stability Management for high active driving safety in maneuvers involving extreme longitudinal and lateral acceleration without affecting the typical Porsche agility. It comprises the following features:
Longitudinal dynamics control
- ABS 4-channel anti-lock brake system
- ABD Automatic brake differential
- ASR Anti-slip control
- MSR Engine drag torque control
- EBD Electronic brake force distribution
Lateral dynamics control
- FDR Driving dynamics control (wheel-specific braking intervention)
Enhanced longitudinal dynamics control
Enhanced longitudinal dynamics control is a new feature for rear-wheel-drive models. It improves braking functions and active safety, in particular, by reducing stopping distances via the following additional functions:
- Improved braking readiness through prefilling of the brake system
- Brake assist
- Drive-Off Assistant
Enhanced braking readiness
The enhanced braking readiness through prefilling of the brake system serves to shorten the stopping distance in emergencies. When the accelerator pedal is released very quickly (an action that typically indicates imminent emergency braking), brake fluid is pumped from the PSM hydraulic unit to the wheel brakes before the brake pedal is actually pressed. As a result, the brake pads are gently applied to the brake discs, preparing the brake system for the impending braking operation. This significantly reduces the deceleration build-up when the brake pedal is sub-sequently pressed, thereby substantially improving the brake system's response and shortening the stopping distance.
Brake assist
The brake assist facility also reduces the stopping distance. In addition to vacuum-controlled brake boosting via the brake booster, additional hydraulic brake boosting also takes effect in response to full braking. On identifying full braking, i.e. when a defined actuating speed and force is exceeded on the brake pedal, the PSM hydraulic unit actively supplies the required brake pressure for maximum deceleration.
For improved sporty driving, the brake assist and therefore the additional brake booster function is deactivated when PSM is switched off (PSM OFF) or when the Sport button is pressed in the optional Sport Chrono Package Plus.
Drive-Off Assistant
All new 911 models both with manual transmission and with the new Porsche Doppelkupplung transmission (PDK) feature a Drive-Off Assistant as standard. It prevents the vehicle from rolling forward or back on a hill for a limited time by holding the vehicle automatically and in a controlled way using the operating brake. The Drive-Off Assistant allows the driver to take off comfortably and smoothly on a hill without applying the handbrake.
Essentially, the entire Drive-Off Assistant function depends on the position of the vehicle on the hill and the desired direction of travel as well as the selected gear. The Drive-Off Assistant is active if the vehicle is facing uphill with a forward gear engaged. The function is deactivated when you put the vehicle into reverse gear in order to park the vehicle for example. The Drive-Off Assistant is only active in reverse gear if the vehicle is facing downhill.
As soon as the vehicle comes to a stop on a hill by specifically using the brakes, the hydraulic brake pressure selected by the driver prevents it from rolling forward or back. The vehicle holds for as long as the driver keeps the brake pedal pressed. When the brake pedal is released, the PSM hydraulic unit slowly reduces the brake pressure after a maximum time of approx. 2 seconds, thus disabling the automatic hold function. The brake pressure is also reduced when taking off on a hill if the driver accelerates (on vehicles with PDK) or accelerates and releases the clutch (on vehicles with manual transmission) immediately after releasing the brake pedal, thereby building up sufficient drive torque.