Just a thought...would a spool (locked differential) and an electrically controlled torque box on either side leading to the rear wheels work?
With bias control available from the steering wheel, you would effectively have an infinite control of the torque or power to each side, and the trailing power leading into a turn would also be controllable.
I know the several manufacturers use these things to balance power to the front in 4 wheel drive applications, so using 2 of them of the correct size should not be a problem.
As I said...just a thought.
Bob

I'll throw my hat in with some of the other guys on the Guard Ltd . I used to break Quaiffe's frequently in my car and though the customer service was fantastic and they would always send me a new unit I eliminated the problem when I went to the Guard .

Bob - What's a torque box?

Some of the World Rally Cars used to have hydraulically controlled LSDs which seemed very effective but these have now been banned but the technology certainly exists.

How about a FTT (Front Torque Transfer) system from a 90's F1 car appied to the rear? ;)

Chris:....my brain seized when I described the box.
What I meant was an electrically controlled viscous coupler.
These are used in 4 wheel drive vehicles to couple the power to the opposite end and sometimes side to side.
The inside of them looks like a torque converter with the liquid viscosity controlled by DC voltage (or current).
I have seen these about 6 - 8 inches in diameter pushing power from a 100HP electric motor.
In operation, they build up some heat, and usually have fins on the outside to help the cooling.
If you look up Viscous Drive....one picture will explain everything.
Bob

Any experience with the Wavetrac LSD yet on 911's?

Is this what a quaife is for? :eek:

YouTube - VW Beetle Quaife gearbox test

Care to explain the logic behind this statement? When an LSD experiences a certain amount of wheelspin it's going to lock. Whether or not that's in a corner or on a standing start off the line it's going to be the same. When one drive wheel begins to spin the LSD is going to lock and split the power between both wheels, given the car better traction.

Even though this seems to be a year old thread, I have experience with Wavetrac in 2 applications. I have an '85 911 track/street car with a modified Euro 3.2L, coilovers and a '74 911S 7:31 short gear box. It's a very happy puppy with great scoot and handling. I love the Wavetrack, it puts down the power on short technical road courses with numerous slow tight turns and elevation changes in my region and the cars behavior under decel, braking and trail braking is exemplary leading me to believe in the claimed friction on deceleration.

The second car is a track only '74 chassis 911, modified torsion bar suspension, 3.8L built racing motor and a re-geared/modified G50/01 with a shortened bell housing. When I was completing this car I didn't hesitate to use Wavetrack again and I LOVE the end result. Again, I can drive the car rotating around apexes with controlled throttle input pointing it exactly where I want it and accelerating hard through the exits... I've driven 911s with good stock Porsche LSDs and one with a Guards built LSD and my sweet spot was instantly struck with the Wavetrac. Bang for the buck, for a unit which has never put a wheel wrong for me, I'll continue choosing it for any future projects.

Dave.

The Wavetrack seems to be an advancement in technology with more flexibility for decel and aceleration out of corners. The ads show how the plates react to different torque between wheels and it seems to allow the differential to revert to a simple unlocked unit when everything is even. I have one for my VW GTI but not for my 911...yet.

I don't know if it was you or someone else who made the post but on another board there was some guy asking about there being no warranty on our parts. The responder said that Quaife has a lifetime warranty and you will use it multiple times in your life. The Guard has no warranty and does not require one. :D Thanks for the endorsement.

As for the Wavetrac? There's some good commentary from owners, as wel as Steve Weiner, in a thread over on Rennlist:
Diff between a TBD and a LSD? - Rennlist Discussion Forums

Been running the Wavetrac in my newly rebuild 915 for about 4 months now. Came highly recommended by my local shop and Patrick Motorsports where I sourced it. So far nothing but positive comments with spirited road use. Car handles well in the curves and under braking... seems mildly passive in normal day to day road use and doesn't have an aggressive oversteer onset feel like my 928 LSD did. I DO feel it working when pushed hard in the curves... Will have my first DE with it in March so we'll see how much of a difference it makes out on the track!

I was looking into building a Spec Z car for NASA (New Spec series)- Wavetrac is the "Spec" LSD- Read their forums...... Some only last a race or two, and if they last, they are having other issues........ Junk in my book.

I thought that was a heat generation in the diff issue more than a Wavetrac issue? I thought that I read Nissan even admitted that there is a flaw in the Z design causing excess heat in diff fluid. I know that NISMO now offers an improved diff cover and diff cooling system.

From what I understand and have seen, there have been failures even when adding coolers. Check out NASA forums spec Z- there is a HUGE thread about it, and there are not many Spec Z cars built.

Drove CMP last weekend... nothing but positive experience out on the road course. Coming out of carousel doing about 70mph got sideways drift going 30-40ft with power down to both wheels instantly. Was able to recover effortlessly.

Overall Car handled well in the "twisties", did not feel any aggressive wheel lock. I'm a VERY happy camper!

We only use GT or old ZF in our race cars. We get replacement discs for the old ZF units from GT.

Cliyde, what do you think caused the tail to wag?

iId only use Porsche Motorsports asymmetric 40/60 w/ GT internals, GT asymmetric or as a last resort the an old style ZF, Porsche street asymmetric's w/ GT internal are pretty good too.

Driver's fault, for sure. :D Pinched the wheel too much tryin to reel it in before the straight. Totally predictable and controllable oversteer... Felt like Tanner Foust out there for a split second. ;)