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View Full Version : Geared Limited Slip Differential options - Quaife, TG, DPI, Truetrac, Wavetrac



Uhcoog1
01-21-2012, 03:59 PM
I've been researching differentials, mostly:
Quaife
Torsen Gleason
DPI
Truetrac
Wavetrac

I've noticed that some advertise preload - specifically the DPI, Wavetrac (though not specifically stated as preload), and Truetrac, who has at least one unit for the ford 9" that advertises preload. DPI says you need to send the unit in for service when the preload gets below a certain point; does the unit lose the bias ratio advantage over that of an open diff? I couldn't find any data for the Quaife and the Torsen Gleason on preload. I can see the advantage of the preload, but it's introducing a wear item (true at least for DPI and probably Truetrac; Wavetrac advertises it's a locker style preload- interesting).

One of the advantages of the gear type limited slip differentials is not having to perform maintenance, but do the units wear out at some point? How is the ~3:1 bias ratio achieved? Through mechanical advantage of the gearset? Through friction on the gearset? Are they all the same, more or less, or are they all slightly different?

I'm trying to figure out what makes them tick, so I can make an informed decision on which one I want.

Bryce
01-22-2012, 11:07 AM
I just did a lot of research on the detroit locker and wavetrac.

I decided on the locker... The wavetrac seams to have a carbon fiber wear surface that does not wear out, manufacturer claim that no servicing is required. All biasing diffs will apply a bias ratio (example 3:1) to the tire with traction. So if the inside tire is spinning and get 20 ft-lbs of torque the outside tire will get 60.THe wave track is teh same until the inside tire has no traction.

Uhcoog1
01-22-2012, 12:18 PM
Thanks for the info on the wavetrac! I sure wasn't able to find anything on that one.

ponchopwr70
02-01-2012, 09:42 AM
I've been doing some research for a 9" and I'm going with a billet clutch posi most likely strange. Reason is some of these gear driven centers seem to eventually break and the wavetrac is to new and expensive to really know. I've broken gears in transmissions and can only imagine what slicks will do to a tru-trac. Clutches are $100 and fairly staight foward to replace. Also I herd that there can be problems with grinding while shifting with a locker due to the slop they have in them.

Bryce
02-01-2012, 01:38 PM
I have an automatic in front of my locker and have no issues with "slop". I only notice it going from reverse to forward.

BTW, I autocrossed my car for the first time last weekend and I love the locker. Worked great with no side effects.

carguykeith
02-01-2012, 04:15 PM
There are plenty of people running 10's at the drag strip with truetracs, I was concerned too but couldn't find any failures to speak of.

ponchopwr70
02-03-2012, 06:40 AM
http://ls1tech.com/forums/drag-racing-tech/1269690-another-trutrac-fail.html

some info here on tru tracs, like always, research before you buy.

funcars
02-09-2012, 07:17 PM
I use a DPI Black Gold full tight unit for the track. It works well for me and has a breakaway spec like a posi and puts torque to the wheel with the most traction like a torsen. I can get on the throttle earlier than with the auburn posi I used to run and they are both much better for me than the locker I ran before, but some do like them - it's personal preference and driving style. Look up on the DPI website for more details of how the gears function or better yet call them and ask questions if you are interested. It's probably a waste of money for a pure street car or a street/drag combo car.

It's worth doing some investigation regarding durability for what ever your application is as well.

68sixspeed
02-09-2012, 07:43 PM
I switched to a tru-trac in my car last year and have been very impressed so far. Straight line performance of a detroit locker but it actually lets the car go through the corner!