Planet 9

A limited slip differential (LSD) is a modified or derived type of differential gear arrangement that allows for some difference in rotational velocity of the output shafts, but does not allow the difference in speed to increase beyond a preset amount. In an automobile, such limited slip differentials are sometimes used in place of a standard differential, where they convey certain dynamic advantages, at the expense of greater complexity.

The main advantage of a limited slip differential is found by considering the case of a standard (or "open") differential where one wheel has no contact with the ground at all. In such a case, the contacting wheel will remain stationary, and the non-contacting wheel will rotate freely– the torque transmitted will be equal at both wheels, but will not exceed the threshold of torque needed to move the vehicle, thus the vehicle will remain stationary. In everyday use on typical roads, such a situation is very unlikely, and so a normal differential suffices. For more demanding use however, such as driving off-road, or for high performance vehicles, such a state of affairs is undesirable, and the LSD can be employed to deal with it. By limiting the velocity difference between a pair of driven wheels, useful torque can be transmitted as long as there is some friction available on at least one of the wheels.



To see the installation of a LSD style unit Click Here -> Article Forthcoming Stay Tuned

The acoustics of this dual-mode sports exhaust system are dependent on driving style, ranging from standard output during normal road driving to a more aggressive tone during performance use. Modes are selected using a button on the center console (or ‘Sport’ mode button on vehicles with optional Sport Chrono Package/Sport Chrono Package Plus).

Introduction planned for 04/2007. Some models may require additional components. For detailed information about this product, please contact your Porsche dealer.

Part no. 987 044 200 00

Click Here for the FAQ on the Porsche Sports Exhaust

This active damping system offers continuous adjustment of individual damping forces based on current road conditions and driving style.

The driver can choose from two setup modes, ‘Normal’ and ‘Sport’, using a separate ‘damper’ button on the center console. ‘Normal’ mode is designed for general road driving and circuits with uneven tarmac. ‘Sport’ mode is intended for smoother track surfaces, where the harder settings help eliminate pitch and roll.

In either mode, PASM continuously evaluates the current conditions while automatically selecting the corresponding damper rates from the respective set of mapped values.

A range of sensors are used to monitor the movement of the body under acceleration, braking and cornering maneuvers, as well as on poor road surfaces. The PASM control unit then evaluates this data and modifies the damping force on each individual wheel in accordance with the selected mode. The result is a significant reduction in body movement as well as a better grip on the road.

For example: if ‘Sport’ mode is selected, the suspension is automatically set to a harder damper rating. If the quality of the track surface falls below a certain threshold, the system immediately changes to a softer rating within the ‘Sport’ setup range. When the quality of the tarmac improves once more, PASM automatically returns to the original, harder rating.

Need more information about PASM? Click this link: FAQ for PASM