[Mark Hubley]

Last December I bought a 2015 Cayman GTS. According to the seller, and according to the Certificate of Authenticity that came with the car, it has the Porsche Torque Vectoring option. According to information I see on the Interwebs, PTV includes a limited slip differential. So, I have been assuming my car has an LSD.

Recently, I had the car on my lift to swap wheels. While I had the car up in the air (and transmission set in 1st gear), I rotated one of the rear wheels (forward direction), and I noticed the other spun in the opposite direction (as if in reverse). I was under the impression that if a car has an LSD, both wheels will rotate in the same direction.

Does this mean my car does not have a limited slip diff?
Or maybe with this particular LSD it is normal for the wheels to rotate in opposite directions when testing like this?

[Patrick3000]

PDK or manual?

[zygomatic]

Have you tried putting the VIN into VIN Analytics? 220 will be the PTV/LSD option code.

As far as I know, if it has PTV, your Cayman will have a mechanical LSD in addition to the electronic wizardry that assists the driver.

[racer]

These sites indicate that with a manual trans with PTV, you get a traditional LSD. With PDK, you get a different version of PTV called PTV Plus which is electronic

https://www.porschefremont.com/porsc...que-vectoring/

https://presskit.porsche.de/specials...-ptv-plus.html

The system is available in two variants: In combination with a manual transmission as PTV with mechanical differential lock and for PDK vehicles as PTV Plus with electronically controlled, fully variable differential lock.

[Mark Hubley]

The car has a manual transmission, and according to stickers and various documents, I have option 220. According to Dave's second reference, this means the electronic torque vectoring "with mechanical differential lock." A page on the Planet-9 web site with a list of option codes shows it as follows:

220 PTV Porsche Torque Vectoring incl. mechanical LSD

I wish I were a skilled enough driver with enough experience in a variety of Porsches to be able to just feel whether the car has an LSD or not. I have participated in about a half-dozen autocross events with the car, and it certainly handles better than any of my previous cars. However, when you look at the list of Porsches I have owned, there are a lot of variables that contribute to the difference.

So, is it odd that when I spin one rear wheel, the other spins in the opposite rotation?

[tbernard]

Depending on the number of miles on the car, the clutch plates in the diff maybe toast. Factory Porsche LSD's are not the most robust units. It sounds like your LSD needs a rebuild.

[Mark Hubley]

Just crossed the 20,000 mile mark last week.

[Patrick3000]

Originally Posted by Mark Hubley

The car has a manual transmission, and according to stickers and various documents, I have option 220. According to Dave's second reference, this means the electronic torque vectoring "with mechanical differential lock." A page on the Planet-9 web site with a list of option codes shows it as follows:

220 PTV Porsche Torque Vectoring incl. mechanical LSD

I wish I were a skilled enough driver with enough experience in a variety of Porsches to be able to just feel whether the car has an LSD or not. I have participated in about a half-dozen autocross events with the car, and it certainly handles better than any of my previous cars. However, when you look at the list of Porsches I have owned, there are a lot of variables that contribute to the difference.

So, is it odd that when I spin one rear wheel, the other spins in the opposite rotation?

Dave gave you the link above.

With the manual gearbox you have a full mechanical LSD, you choose wisely

What Does Porsche Torque Vectoring Do?
There are actually two versions of the Porsche Torque Vectoring feature: PTV, which comes on models with a manual transmission, and PTV Plus, which pairs with PDK. Regardless of which version you have, the PTV system will improve vehicle stability and dynamics.

How Does Porsche Torque Vectoring Work?
Working alongside the rear differential lock, PTV works by intelligently braking the rear wheels as circumstances dictate. In order to allow for tight cornering, this feature will apply moderate brake pressure to the inside rear wheel. In turn, this means a greater amount of drive force is sent to the outside rear wheel. This creates an additional rotational pulse, also known as yaw movement, around the vertical axis of the vehicle. Combined, these actions deliver a direct action from the turn-in point, allowing for superior handling around the streets of San Jose and Los Altos.

PTV vs. PTV Plus
With standard PTV, the rear differential lock is regulated mechanically. PTV Plus, on the other hand, offers fully variable torque distribution thanks to being equipped with electronic control. Joining forces with the Porsche Stability Management (PSM) system, Porsche Torque Vectoring increases stability on slick roads, in snow, and on roads with varying levels of traction.

[racer]

I'd hate to think they wore out in 20K miles.. but I've heard of such numbers for track cars for instance. Not sure of the cars history.. and well, any performance driving will only accelerate the wear. Any CPO warranty coverage?

[trytryagain]

As far as discerning whether the LSD is working, under hard cornering, when the inside wheel is barely making contact or is actually raised above the track surface, you will hear the revs increase abruptly if the LSD doesn’t lock the wheels together.