Wavetrac LSD??
 

Has anyone used or had experience with the new Wavetrac LSD's? They look pretty good but I would like to hear from anyone that has one.

Going in a 993 G50 6spd with a 400hp turbo engine.

Thanks

Subscribing. I am also interested in the pro's and cons of this LSD. Could not find any experience from the Porsche crowd as it seems to be mostly used in VW's

I saw their ad in Excellence last month and had a look at their website today.
The price is pretty reasonable. Wavetrac® Differential - A torque biasing differential with a difference
I wonder if some of the pros could weigh in on this one.

A quick search looks like a lot of the BMW's are using them on the track.

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Lifetime transferable warranty, good price, built by Moser...........sounds good

The main issue with Limited Slip Diffs is chosing the optimum solution for a specific application.

Torsen type diffs do have some advantages over plate type differentials.

They are less prone to wear, quiet in operation and quite smooth in their action.

They can also be designed to provide a higher Bias Ratio than a plate type diff so they can be better on slippy surfaces.

The problem with Torsen Type diffs is that they have no Bias when a wheel is unloaded as sees zero torque and they they have no bias on coast (ie trailing throttle).

I discussed the Wavetrac at some length during a recent Race Car Show but didn't really get great answers.

I understand that Bias Ratios of about 4:1 are typical and this is similar to the Quaife unit.

I also understand that they maintain some bias when there is zero torque on one wheel, which is an improvement on the Quaife.

I also see that it is possible to modify the 'preload' by using plates which is another difference between a typical Torsen and this uint.

I am not convinced that they have any torque bias on a Trailing Throttle (Coast) which is a major disadvantage when it comes to a Porsche Race Car. I aksed the question but the answer really described the zero torque condition.

Many people in UK seem to like the Quaife unit as it will improve traction on wet roads but it doesn't tend to introduce to much understeer as it effectively has zero preload. IIf you increase the static preload you will begin to introduce some understeer)

It doesn't, however, have any effect on Trailing Throttle Oversteer (TTO) as it has no torque bias in the coast condition and this limits its value for track use.

A plate diff with a shallow coast ramp will help to stop the unloaded inner rear wheel from locking and allow the brake bias to be moved rearwards which will shorten stopping distances.

If I had to choose I would still pick a Plate diff for track use and units made by Drexler Motorsport and X-Trac (Xtrac - Transmission Technology) are very good.

For Road use I think the Quaife is great value as the cost (at least in the UK is relatively low)

I am sure the Wavetrac is also very good but I am not sure it offers great advantages over the Quaife depending on the cost difference. If it were the same price I would think its a good buy.

The links to the Porsche diff's on their website are not working. I wonder if they are still in "developement".

For a Porsche, I'd stick with Guard Transmission clutch-type LSD......

Scott

Thanks for the info so far, too bad no one has any hands on experience with these yet......

I sent emails to Drexler Motorsport and Xtrac requesting information and pricing, I will let you all know what I hear back.

I noticed that IMGT3 offers the Quaife for $1271 making the choice a little more interesting.

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No personal experience but remember reading early units had some considerable issues with noise followed closely by diff failure. Not sure if this is true of recent wavetrac diffs or not. I'll post if I find the stuff I read.

I talked with Autotech about the Wavetrac and they said that it is similar to the Quaffie but stays engaged in breaking and provides more connection during coasting. Good for VWs and front wheel drive. I have also talked to Porsche shops that don't like Torsen typs LSDs for Porsche but it is still not clear why. I was looking for a LSD for my 86 Carrera but want to maintain the best connection to the road.

I just bought one, I'll let you know if it works.

Thanks Steve, how soon are you installing it?

Guard LSD for track use....... Getting lock up under decel is important to me.

Cheers

The vast majority of Torsen Type LSDs behave exactly like an open diff on a trailing throttle and only provide an improved traction on the power side and I think this is of lmited (no pun intended) value.

The plate diff, particularly with a 20 degree coast ramp, will prevent lock up of the inside rear wheel under heavy braking and will help to significantly reduce the trailing throttle oversteer.

As Jeff says keeping a decent level of torque bias under decel is the main reason for fitting an LSD in a 911.

Wavetrac don't seem to be able to specify the torque bias under decel conditions and this must be a concern.

Unless thay can provide a bias factor of around 2.5:1 on the coast side I would stick with a plate diff.

i run one in my 914-6GT, i like it a lot
Hans

I don't track my car but I am putting more than 350 HP through the 915 resulting in a lot of wheel spin on acceleration so I am not really concerned about braking effects. I am doing this a part of a general improvement of the 915 with the addition of a billet bearing plate and billet differential side plate with replacements of all bearings and likely a pinion bearing race repair.

Interesting - I don't think an LSD will help much with wheelsin off the line but should be good at stopping the inside wheel spinning out of corners.

The Quaife will typically give a torque bias of about 4:1 in this situation and I would guess a Wavetrac will be similar.

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. ;)