I have replaced the Limited Slip Differential in my 2007 GT3. The original was more than a little used, actually worthless by the time I got the car with around 12K miles.

I am lucky enough to have GMG practically in my backyard, they'll pick me up and deliver me back to my house.

So I went with their recommendation and installed the Carbonetics. Now that it is broken in, what a difference! The car was very loose before, especially on the over run. Now it is much tighter feeling into and out of the throttle on turns etc.

I cannot present myself as an expert nor do I want to take anything away from other brands/installers as I have no comparable experience with which to share opinions on one versus another. However for the people in SoCal, Orange County I would recommend the GMG carbonetics route.

I need to get back to them for the Xmission fluid change after the break-in now.

 

Howdy -

What were the symptoms on the street? My 07 GT3 feels like it's kind of 'shimmying' when i power out of a turn. Doesn't really feel loose, but it feels like the power is not being laid down linearly. I don't track my car, and don't plan on it any time soon.

Should I take it in for an exam?

Thanks for any help!

 

did they say why they prefer the carbonetics?

how does it differ from other options?

 

Chiffonade, the first symptoms were two really cool autocross spin-outs...........but I had the car up on my lift and did the "spin" test and it just seemed like an open transmission. Fabryce at GMG confirmed this and in fact the teardown revealed as I was told. In driving the car was very loose in the back when powering on. At throttle off or down the rear end would wriggle at high speed shut down. Mid-corner throttle lift (I know you're not supposed to do this but hey) would really get the back in nervous. The car now seems to "hunker" down much better on applied throttle out of a corner almost as if it tries to point itself straight off the back wheels. Throttle shut down from high speed is not dramatic and the car doesn't give any rear wheel over run when do so.

PJS, I have to admit I went with the advice of trusted people who I've worked with on a couple of cars for a few years. So, I don't want to say that mine is the optimum choice, but it was convenient that is for sure and it has seemingly taken care of my major complaints. There are various type of Limited Slips but the type that use slip plates either use an applied metallic coating or some other applied coating on a flat plate subtrate to maintain traction against each other. Carbonetics uses carbon and they claim several advantages from doing so. They are a relatively large company and have a reasonable amount of time in the business.

For a reasonable explanation of the subject in general look at the mikymu thread on the same subject. One of the LSD suppliers does a fine job of exploring the subject.

 

how civilized is it for daily driving?
the reason I'm asking is this recent thread -> https://www.6speedonline.com/forums/...h-vs-gear.html

 

When first put in my LSD was very noticeable, and it growled and graunched around corners and in reverse. The car didn't like acute corners. After 500 miles it has settled down and become very civilized and almost invisible in operation. I don't have a problem with it on a daily basis on the street.

I read through the link you provided AlexN and one gentleman from Scotland was unhappy with his twin turbo in snow after an LSD was installed. Of course no snow in California unless you drive to it so I can't relate to his issues.

 

Have you still got the stock unit that they removed from your car? That can be rebuilt and sold to a member who drives a 996 or an Aircooled 911 with G50 who didn't have an LSD from the factory. Properly serviced the factory unit is more than adequate for street and track use.

 

Hah speaking of which Matt... We need to send you two factory um... "open diffs" from a pair of green RS' Kermit is downright scary at the moment:P

 

No I didn't keep the previous stock unit. I didn't think to ask as I didn't realize they were rebuildable!

 

I can't seem to understand how these things go bad after only 12k miles. I personally have about 7k on my car and I just am curious how the LSD on a $120,000 car goes bad that quick!! I know for the guys that track there car 15-20 times a season I'm sure it tires fairly quick, but for us that go 5-10 times a season is it something for us to worry about? Why is it so weak from the factory that it needs replaced/rebuilt so soon?

 

Misanors4,
Search for a thread titled "LSD Buster". It should answer your questions.

 

Roger that. Thanks for the help.