Porsche Traction Management (PTM)

Porsche Traction Management (PTM)







The active all-wheel-drive system, Porsche Traction Management (PTM), which is standard in the new Panamera 4S and Panamera Turbo, is designed to influence longitudinal and lateral dynamics. The system provides increased driving stability, traction and more agile handling, depending on the driving situation.

PTM comprises the following systems:
- Active all-wheel drive with an electronically controlled, map-controlled, hydraulically activated multiple-disc clutch
- Automatic Brake Differential (ABD)
- Anti-slip regulation (ASR)

Benefits of Porsche Traction Management (PTM)

General benefits:
- Extremely agile and dynamic
- Very good traction and vehicle stability
- Good control of the vehicle and driving safety in extreme driving situations

Compared to conventional all-wheel drives:
- Reduced weight and consumption due to its compact construction
- Improved driving performance thanks to the low centre of gravity of the engine

Other features:
- Further improved traction with Automatic Brake Differential (ABD)
- Further improved vehicle stability during acceleration with anti-slip regulation (ASR)

Porsche Traction Management (PTM) actively improves vehicle handling and increases traction in the new all-wheel-drive Panamera models. Strictly speaking, driving dynamics and traction are one and the same thing since the transitions within the systems are performed smoothly. Here is a example: Only when a vehicle has good traction, i.e. the tires do not build up any excess slip, can lateral forces also be transferred. This means steering control for the front axle, and lateral support for the rear axle. Drive wheel spin can be reduced - or ideally, eliminated completely - using PTM.

With PTM, the active all-wheel drive in the Panamera is designed as a controlled hang-on all-wheel which has been integrated into the main housing of the Porsche Doppelkupplung (PDK). The electronically controlled multiple-disc clutch installed in the PDK regulates the distribution of drive power between the full-time drive rear axle and the front axle in a way that is fully variable without a fixed basic distribution. Permanent monitoring of driving conditions enables the system to respond to different driving situations. Sensors continuously monitor various parameters, including the speeds of all 4 wheels, axial and lateral acceleration of the vehicle and the steering angle.







If the rear wheels are turning during acceleration, for example, additional drive power (if necessary up to 100% more) is distributed forward through greater intervention of the multiple-disc clutch. The all-wheel drive is therefore fully variable. ASR also reduces wheelspin. In bends, only the right amount of drive power reaches the front wheels to ensure optimum lateral support.

Drive power is transmitted to the front-axle differential via a beveloid gear in the hang-on all-wheel. The helical gear wheels mesh in two planes, permitting the connecting shaft to the front-axle differential to be installed at an inclination of 11 degrees. Compared to a conventional transfer gear, this solution is more compact and is approx. 6.6 lbs. (3 kg) lighter. The weight reduction continues with the hollow connecting shaft fitted to the front-axle final drive.







Another innovation in this segment is the front-axle differential, which is bolted directly on to the engine. The front drive-through axle through the engine keeps the engine in the Panamera sitting particularly low. This lowers the center of gravity and improves driving properties. A particularly compact and low-weight design is characteristic of this area also.

PTM works with the enhanced Porsche Stability
Management system to ensure that power is distributed appropriately for excellent propulsion in every driving situation: on long straights and in tight corners as well as on surfaces with varying levels of grip. The Automatic Brake Differential (ABD) feature also improves traction. When the brake control systems are actuated, PTM disengages the front axle completely to facilitate PSM interventions on individual wheels.







Depending on driving conditions, the torque is distributed from the hang-on clutch (HOC) to the axles according to load to guarantee permanent traction for all wheels. The inner disc carrier on the HOC is pressed onto the front axle shaft, which is connected to the side shaft via beveloid gear teeth. The outer disc carrier of the HOC is firmly welded to the parking-lock gear and is mounted on the rear axle shaft. Like the double clutch, the HOC is a wet clutch and is supplied with oil through the oil pipe.







Rear Axle Shaft With Oil Pipe and Oil Jet







The oil for actuating the HOC flows at a maximum pressure of 304 psi (21 bar) directly through the oil pipe. The cooling oil travels between the oil pipe and the inner wall of the rear axle shaft to the HOC at a maximum pressure of 80 psi (5.5 bar). Some of the cooling oil is routed to the oil jet and from there injected into the drive shaft to cool/lubricate the bearings.