LSD on C4S

[alexcwt]

Does my 03 C4S come with LSD. I have PSM. When I do donuts, both wheels spin at about the same rate. I still like confirmation that I have LSD. The option sticker doesn't show the code.

[Loren]

All cars with factory LSD would have either option M220 or option IX75 (MY04 and newer).

[navin in KC]

what is LSD? (other than a drug)

[Loren]

LSD = Limited Slip Differential

Limited slip ensures that some torque is always distributed to both wheels, even when one is on a very slipper surface. Most of Porsche's LSD options offer 40% locking.

From the GT3 overview

Since, owing to its rear-mounted engine and the resulting axle-load distribution, the 911 GT3 is able to convert engine output into forward propulsion very efficiently (good traction) even under poor road conditions (e.g. wet surface), a locking factor of 40% is sufficient in the acceleration phase.

Higher locking factors would have a detrimental effect on the cornering ability of the vehicle without any significant improvement in traction.

The locking factor in the overrun phase is 60%. The value for the overrun phase is higher than that for the acceleration phase since the engine drag torque is less than the maximum engine torque. Additionally, this configuration prevents the vehicle from oversteering in the ev ent of load changes when cornering.

The limited-slip differential was designed as an element of the overall driving dynamics configuration of the 911 GT3 and should only be regarded as a complete system with respect to the overall characteristics of this vehicle.

[Palting 996 C4S]

Don't PSM cars have ABD, an electronic method coupled to the ABS, to act as an LSD?

[SPR]

It would be my guess that much like mercedes esp, the psm is coupled with an open differential that merely breaks the wheels like the porsche traction control however it uses yaw sensors to do the input instead of a wheel speed sensor - also maybe using the wheel speed sensor as well. That would be nothing like a LSD. LSD transfers power to both wheels whereas the esp function and maybe psm would merely brake a wheel to limit slip- again, more like traction control

I didn't know that you could get the LSD on a 996 on anything other than GT cars and my 99.

Don't PSM cars have ABD, an electronic method coupled to the ABS, to act as an LSD?

Edited February 18, 2006 by SPR