Anyone here using a limited slip front diff? I really need to know how much it improves traction. I would like to get a quaife but I read this:

>HOWEVER, if there is NO traction (one wheel off the ground, or bad tires on ice) they will not transfer power.

Is this true?

Thanks!

If one front wheel is off the ground, LSD will GIVE you the traction, actually.

Open diff will transfer the power to the wheel that's spinning and you'll get no traction.

Yes, but I read with torsen diffs, that if there is ZERO traction, or close to, there will be no power transfer between wheels.

I need to figure that out before I decide on a quaife or a kaaza...

Thx for the help

I agree with go go go. by definition, limited slip diff will make the slipping wheel cause friction, mechanics, etc. to get the other side spinning.
so, what kinda stuff are you guys doing that requires front LSD?:)

An LSD is a good idea reguardless of what kind of driving you do. Although having MORE power helps justify the cost.:D. Id go for the Kaaza diffs set at 50% lock-up front and full lock-up rear(if you have the oversteer balls:rolleyes:) with a WRX RA viscous center for streetablility purposes. That's my planned set up.

-scu

hmm... I'm trying to picture AWD with one front wheel smoking from wheel spin:D

is there such thing as 'one-way' diff for street cars? can that be used as center diff for safer e-brake turns?;)

What's a kaaza?

Isn't it Kaaz?

I'd get a front LSD off of UpGarage in Japan or Yahoo Japan. Those are the cheapest places to find LSDs.

I think I found the answer:

kaaz, is permanetly locked, with a small percent of unlock. So if a wheel was in the air, it would still get torque.

With the quaife, the wheel in the air would stop turning and the other wheel would get the torque.

Originally posted by John #555
hmm... I'm trying to picture AWD with one front wheel smoking from wheel spin:D


http://66.57.73.182/SpectraSite/images/rome/imagepages/image116.htm

There you go :-)

I know ILP performance in PA can get you one.

Just keep in mind the front LSD is going to cost around a grand and then you still need a shop thats capable of installing it.

Originally posted by N/A
Just keep in mind the front LSD is going to cost around a grand and then you still need a shop thats capable of installing it.

Yea, I'd try to find a local shop that could do both.

Originally posted by trhoppe
http://66.57.73.182/SpectraSite/images/rome/imagepages/image116.htm

There you go :-)
:eek:
thanks. now i can use my head for imagining other better things...

i'm going to do the install myself. The quaife is 695 from teagues auto, sounds good to me...

I think that with torsen diff like Quaife, even when one wheel is completely off the ground, it takes a while before the friction force goes away with in the drivetrain, so it would see sends torque to the other side. Now if the wheel has been lifted up, then yes, no torque transfer (vs the locking the diff with other types of differential)

Originally posted by Keiho
What's a kaaza?

Isn't it Kaaz?

DOH! I was downloading music from Kaaza at the time I posted. My bad!:D

-scu

Torsen differentials, like the Quaife, require some traction on both wheels in order to work properly. If one wheel is in the air, all power will go to the unloaded wheel and the car will go nowhere.

However, if the light wheel has some traction, the Torsen will split the torque so the majority of the torque goes to the wheel with the majority of the grip.

Kaaz diffs are clutch plate diffs that lock under acceleration. The harder you accelerate, the harder they lock. They have friction disks inside that can be arranged to provide 33%, 66% or 100% lockup. Kaaz diffs usually come in a 1.5-way configuration. This means they lock 1/2 has hard under deceleration as they do under acceleration.

Gary
Sheehan Motor Racing
www.teamSMR.com

Gary is right. With a torsen LSD system, if there is absolutely 0 traction, then it wont transfer the power, because of how it works. Other LSD's will, like the clutch type, or a viscous coupling. It is arguable though that torsen diffs have other advantages.

-Wes

What does installation of a front LSD run? It's in the deepest part of the tranny so I've heard up to $1k...

For ~$1k for a Suretrac I'd almost be tempted to spring for an STi 6MT with LSD built-in at that point.

Also keep in mid that the Torsen type is heavier than the clutch type. There is a way to "fool" the torsen by quickly applying the brakes. Fine for off roading, not so good for racing.

I am curious about installation cost as well. How many hour job is this for a shop? I wouldn't need to have the trans removed from my car, because the trans I would be putting it on in sitting in my basement.

-Wes

Wes,

For a first time job, I'd say give yourself 8-12 hours. You'll most likely want to poke around in there, clean stuff out, see how everything comes apart and goes back together, etc.

The hardest part is setting the backlash between the ring gear and pinion gear. It requires a special paste you apply on the ring gear so you can see the contact pattern. You'll need to assemble the 2 halves of the tranny, set the backlash, cycle the input shaft through several revolutions, then disassemble to check the pattern. If you got the pattern right, your ready to seal the tranny up with MIPG (Make In Place Gasket) and bolt it up. If the pattern is not right, you've got to try again.

It's all in the manual, and a first timer can do it. It just takes time.

There is one special tool you will need. It is used to turn the threaded bearing cups to adjust lash. I took an oil filter socket and used a grinder to cut notches in it so it would engage with the cup. Works great!

Or, we might be able to be talked into doing it for you...

Gary
Sheehan Motor Racing
www.teamSMR.com

Hi Gary,

Thanks for the installation tips. We will be working on it in a few weeks. Great idea using the filter wrench!

(our sube is a rally car, so the front diff is a very important upgrade for us)

I have a Quaife in front and a Subaru branded "AP Suretrac" in the rear

Works nice..