[bedrock]

I'm finalizing my order this week for a new Boxster S. I've spent several hours researching this forum and have learned a great deal from everyone's posts.

One thing I haven't been able to find is a significant recent discussion on the Porsche-installed limited slip differential from owners who have been using them on their Caymans/Boxsters since Porsche finally made them a factory option. (However, there are lots of older threads on why Porsche needs to get an LSD, and about the best aftermarket options)

This is my first true performance car and I will be using it as a daily driver 80% of the time, having some fun on backroads 15%, and the other 5% I'd like to get into track driving. I'm getting a Boxster S PDK with sports chrono & PASM.

Two questions-

1-How much of a difference would an enthusiast driver like myself, (but certainly not an experienced track driver) notice having the Porsche-installed LSD for backroads driving, and the intermittent track run?

2-I live in the northeast and will sometimes be driving on snow. How much does the LSD help with this?

 

[gasman1]

There are no after market LSDs for PDK as yet, so go with the pricey Porsche option. It is worth having the LSD for sure even for street or light track use. I'm hoping that Guard or Quaife will get a PDK unit to get the dimensions from soon so that they can fabricate a prototype. Porsche does not even sell the LSD unit as an upgrade. One must buy or option the entire PDK+LSD trans-axle. As an added note, the torque biasing diffs (TBD) might be a better choice for light street or AX use as they produce less under steer compared to traditional LSDs. Porsche's LSD is the clutch type and is not adjustable like some after market units would be, and it not as robust if heavy racing is your goal.

 

[bedrock]

Good to know about the lack of aftermarket LSD for PDK Porsches.

Anyone driven a Boxster/Cayman on snow/ice with LSD and also one without LSD and notice a significant difference?
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[jaica]

I drive a gen 1 car. I have added a Quafie torque biased differential. It would make a big difference in ice or snow. An open differential will give you as much traction as your lowest tracktion wheel. After that it will spin a wheel. This will give you of how simple is an open differential:
VIDEO: Fantastic and fanciful old-timey explanation of the differential — Autoblog

In a tight corner you will feel the inside wheel spining and grabbing reapeteadly. It will keep you from adding power until you have straighten the car some more.

 

[bedrock]

That was a great video to explain the differential concept. I did wonder if they were going to explain duck and cover afterward

Sounds worthwhile from the video considering this is 1950s era technology in a 2010 porsche........ I wonder if all cars had differentials for a period and then some manufacturers stopped putting them on their less expensive models?

LSD is beginning to look more and more like a must have for a true performance car.

The only other thing I've been wondering about is PASM?
It seems like a worthwhile investment for the kind of driving I'll be doing 80% daily driver, 15% off-road fun and the rare track day. I like that you can change the feel of the car from relaxing regular drive to more of a sports tuned suspension when you want it.

 

[Dunebasher]

LSD and PASM are options I would take because they save the need for the majority to look into changing items later when they want to push the car a little harder.

PASM provides a very comfortable ride on the street and in sport mode on the track feels fantastic, and is not as good as a dedicated sport/race set-up but for what most can do on the track is more than enough. On the street I sometimes run PASM in Sport mode just to feel how stiff the Cayman can be and it's true sports car feeling.

 

[Nitro8472]

There are no after market LSDs for PDK as yet, so go with the pricey Porsche option. It is worth having the LSD for sure even for street or light track use. I'm hoping that Guard or Quaife will get a PDK unit to get the dimensions from soon so that they can fabricate a prototype. Porsche does not even sell the LSD unit as an upgrade. One must buy or option the entire PDK+LSD trans-axle. As an added note, the torque biasing diffs (TBD) might be a better choice for light street or AX use as they produce less under steer compared to traditional LSDs. Porsche's LSD is the clutch type and is not adjustable like some after market units would be, and it not as robust if heavy racing is your goal.

May you please explain how a traditional LSD causes understeer?!

 

[gasman1]

At low speeds and power, the more locked up the differential is, the harder it is to the change direction. In other words, the car doesn't want to easily turn and prefers to go straight. This ignores any tire slippage or break-away under more power, but only applies when moderate power is applied during a turn. When more power is applied during a turn, oversteer results and is actually exaggerated as apposed to not having a LSD. LSDs also can be set up to slip differently on acceleration vs. deceleration. The braking slippage is usually set higher than the powered slippage in a clutch type LSD in order to get more neutral steering during braking. Sorry I was not more specific on the driving conditions, etc. Translation, ... you are in right that LSDs generally do cause oversteer under racing conditions!

 

[DaveC]

While you may not need an LSD for typical daily driving there are circumstances when a rear wheel will lose grip, at the track, poor road conditions, ice or snow, where the LSD will prove effective. You have optioned the car very nicely and the additional $950 for an OEM LSD is worth it over the long run. I've owned a 99 Boxster, 06 Cayman S, and wife currently has an 08 Boxster S. I would have ordered the LSD for those cars had it been available.

 

[gasman1]

I agree Dave and I've missed having LSD on my last two cars. It was standard on my old 300ZX back in the early nineties, and I loved the traction! They finally optioned it on the 2010 Caymans and it's really worth the extra dough. I'm hoping the various OEMs will get a PDK version out soon.

 

[bedrock]

Have any of you heard of the Porsche LSD breaking down relatively quickly compared to aftermarket LSD? I'm not sure if this is real or just hype by the companies making the aftermarket LSDs......