[Mr. 5]

I know this has been talked about a lot but there's a couple things bothering me about the LSD and welded ring gears.
It seems like the only solution of a person with a welded ring gear is getting a completely different bolt on dif with a Quaife already installed.

My question is, why can't we just get a ring and pinion, install that ring gear to the LSD and then swap that with the inner workings of the welded diff?
This seems to me like it would be the less expensive way to go.

Am I missing something?

[scheherazade]

I just went online and picked up a bolted rear carrier from a scrap yard. I've seen them for as little as ~$350.

Although, I discovered something about the Quaife that bothers me.

It biases torque to the wheel with more force on it, so it achieves a balance. So when you slip, both wheels slip.
BUT.
After you slip, the torque load is gone, and the diff acts like an open diff. One wheel can then grab, and the other can spin. It's not until both grab that the diff begins to work again.

I've read track racing Quaife reviews that pretty much say that when they lift up he inside rear on a turn, it just spins like crazy.

This is why I've started looking at alternatives. Such as a regular clutch type (Sadly they are over-priced), or an input-shaft-torque based diff like the OS Giken or Cusco.

Although the low-load understeer of the OS Giken or Cusco kinda bothers me... (solid axle syndrome, inside rear wheel 'pushes').

I actually wish that the BMW diff was more like the evo's, where it has a Quaife/Torsen like core (to prevent slip), AND a clutch pack to lock things *after* the wheels slip.
Best of both worlds.

-scheherazade

P.S.
FYI
Quaife's main US distributor does installs into welded rears.
I'll look up their contact info as I got it earlier (don't remember off the top of my head).
But yah, you can send them a welded rear end and they will install it.

[dlbrooks18]

Originally Posted by scheherazade

I just went online and picked up a bolted rear carrier from a scrap yard. I've seen them for as little as ~$350.

Although, I discovered something about the Quaife that bothers me.

It biases torque to the wheel with more force on it, so it achieves a balance. So when you slip, both wheels slip.
BUT.
After you slip, the torque load is gone, and the diff acts like an open diff. One wheel can then grab, and the other can spin. It's not until both grab that the diff begins to work again.

I've read track racing Quaife reviews that pretty much say that when they lift up he inside rear on a turn, it just spins like crazy.

This is why I've started looking at alternatives. Such as a regular clutch type (Sadly they are over-priced), or an input-shaft-torque based diff like the OS Giken or Cusco.

Although the low-load understeer of the OS Giken or Cusco kinda bothers me... (solid axle syndrome, inside rear wheel 'pushes').

I actually wish that the BMW diff was more like the evo's, where it has a Quaife/Torsen like core (to prevent slip), AND a clutch pack to lock things *after* the wheels slip.
Best of both worlds.

-scheherazade

P.S.
FYI
Quaife's main US distributor does installs into welded rears.
I'll look up their contact info as I got it earlier (don't remember off the top of my head).
But yah, you can send them a welded rear end and they will install it.

interesting, thanks for the info.. is this how the M diff operates as well?

[Ricky Bobby]

The M diff is much more complex than the quaife LSD. Think of the quaife as something that takes a street car to another level without regard to it being a street car. The M can move power and also has DCT and the computer monitors its activity closer than a heart patient.

[Mr. 5]

So, no ring gear swap?
I'm still confused with why we can't get a ring and pinion, bolt the ring gear to the LSD and then install it into the diff.

[A418t81]

The quaife for the 335 is a torsen diff right? If that's the case, yes, the torsen will require a SMALL amount of force on the spinning wheel in order to transfer power. It'll do it's job all the way up to the car lifting the inside wheel off the ground. I've had 'em in my previous cars and never had a problem with spinning the inside wheel at the track.

Craig, what about the carrier? The ring and carrier are welded together. The LSD goes inside the carrier, and the ring/carrier combo is all bolted (or welded) together.

[Ricky Bobby]

Well the hard part is shimming it all up and making SURE it is right. Thus the bolt in unit at an after core credit cost of $2800 plus labor really isn't cheaper than paying for parts. My feeling is this is better purely because it comes ready to install, all set up and I have a place to call if it decides to fail.

[scheherazade]

Originally Posted by dlbrooks18

interesting, thanks for the info.. is this how the M diff operates as well?

M3 differential is based on wheel speed... like a typical clutch type.

The manner in which the new M operates the clutch pack, I'm not sure about.

Earlier Ms used a simple pump in the differential assembly that would provide pressure when wheels spun at different speeds. This would actuate the clutch packs and make them resist.

A typical wheel speed operated differential would use a weight, swung out by centripetal force (by wheel difference) to actuate the clutch packs.

A lot of the 'intelligence' in a differential is marketing. They 'sense torque', and 'intelligently shift', etc. (blah blah).

Really just "torque or acceleration" forces pushes crap into a "housing or clutch-pack" that causes friction, making it harder to spin at different rates.

Ultimately, with the LSD, the goal is to either :
1) let wheels spin at their own pace
2) force wheels to spin at the same pace


The only main stream system today that _actually_ calculates torque *ahead of time* and assigns it per-wheel, is the Acura SH-AWD system. It has 1 clutch pack per-wheel.
And it's not there to resist and make wheels spin the same speed. It's there to add or subtract torque from each wheel, individually, as the computer deems necessary.

-scheherazade

[A418t81]

My Mom has a 06 RL and while the thing is a turd, in the wet with the traction systems off it's a freaking riot. I've never gotten an AWD car to do such perfect table tops in my life, including my Evo.

[Lowcruzr]

Originally Posted by scheherazade

Although, I discovered something about the Quaife that bothers me.

It biases torque to the wheel with more force on it, so it achieves a balance. So when you slip, both wheels slip.
BUT.
After you slip, the torque load is gone, and the diff acts like an open diff. One wheel can then grab, and the other can spin. It's not until both grab that the diff begins to work again.

Bingo!! The whole point of a Quaife ATB diff is directional stability at speed. If both drive wheels broke loose at 60mph, bad things could happen. One tire spinning allows the other tire to hold the line the car is on.

Originally Posted by scheherazade

I've read track racing Quaife reviews that pretty much say that when they lift up he inside rear on a turn, it just spins like crazy.

I crewed in SCCA for 9 years. I have hours of video footage of inside tires spinning with an ATB diff in the car WHILE THEY WERE STILL SOMEWHAT IN CONTACT WITH THE GROUND!!!

Originally Posted by scheherazade

I actually wish that the BMW diff was more like the evo's, where it has a Quaife/Torsen like core (to prevent slip), AND a clutch pack to lock things *after* the wheels slip.
Best of both worlds.

That would be the super-hot ticket!!

[scheherazade]

What I want is a diff that doesn't interfere with turning when wheels are down, and locks em together when the wheels slide.

Which is basically a standard wheel speed based clutch type.

Sigh... (they cost too much).

-scheherazade

[Mr. 5]

Originally Posted by A418t81

Craig, what about the carrier? The ring and carrier are welded together. The LSD goes inside the carrier, and the ring/carrier combo is all bolted (or welded) together.

Didn't know that.
I just thought that the ring was welded to the open dif.

[scheherazade]

Ring to carrier weld would mean the system is frozen and can't move.

Ring + Diff is the only sensible welded-ring combo.



In any case, I'll look up that shop (I believe it's east coast) that does Quaife installs ino welded diffs. Quaife sent me an email about them, but I'm not at home. Will update this thread with the info later.


edit

FYI :
Drexler
Hartage
OS Giken
Cusco
Kaaz (newer versions)

These are all the same general type of diff. 0-max (usually 100%) lock, based mostly on input torque.

Basically, a center ring is attached to the diff housing.
When the ring gear rotates the diff housing, the center ring rotates.
The center ring has studs on it that press against some wedge-shaped ramps on two side plates.
As the ring rotates, it wedges the side plates outwards, and these plates compress clutch packs.

This kind of diff has understeer issues.
More power on input, means more locking force.
More locking force means wheels can't spin at different rates as easilly.
So if you gun it, while turned, the diff will act like a solid axle, making it hard to turn.
You literally have to break loose the tail to oversteer, OR you have to get some speed, and lose traction on the inside wheel. (FYI this kind of lose traction is not "free spinning", it's just "spinning as fast as the outside wheel while turning".)

Then again, the only point in cranking the wheel over and gunning it is to cause a tail slide... which is a situation you would want a 100% lock with anyways.

You basically want one of these if you're planning on doing lots of donuts, or drifting...

-scheherazade

[Mr. 5]

The e46 M3 diff was incredible and FWIU, it's a clutch type dif.
I really loved the way that dif worked.

[dlbrooks18]

Originally Posted by scheherazade

Ring to carrier weld would mean the system is frozen and can't move.

Ring + Diff is the only sensible welded-ring combo.



In any case, I'll look up that shop (I believe it's east coast) that does Quaife installs ino welded diffs. Quaife sent me an email about them, but I'm not at home. Will update this thread with the info later.


edit

FYI :
Drexler
Hartage
OS Giken
Cusco
Kaaz (newer versions)

These are all the same general type of diff. 0-max (usually 100%) lock, based mostly on input torque.

Basically, a center ring is attached to the diff housing.
When the ring gear rotates the diff housing, the center ring rotates.
The center ring has studs on it that press against some wedge-shaped ramps on two side plates.
As the ring rotates, it wedges the side plates outwards, and these plates compress clutch packs.

This kind of diff has understeer issues.
More power on input, means more locking force.
More locking force means wheels can't spin at different rates as easilly.
So if you gun it, while turned, the diff will act like a solid axle, making it hard to turn.
You literally have to break loose the tail to oversteer, OR you have to get some speed, and lose traction on the inside wheel. (FYI this kind of lose traction is not "free spinning", it's just "spinning as fast as the outside wheel while turning".)

Then again, the only point in cranking the wheel over and gunning it is to cause a tail slide... which is a situation you would want a 100% lock with anyways.

You basically want one of these if you're planning on doing lots of donuts, or drifting...

-scheherazade

I'm really confused, I thought the Hartage diff IS the Quaife? In that youtube video circulating, it's Hartage put together car but the lsd diff used is a Quaife, am I wrong?

[scheherazade]

Originally Posted by dlbrooks18

I'm really confused, I thought the Hartage diff IS the Quaife? In that youtube video circulating, it's Hartage put together car but the lsd diff used is a Quaife, am I wrong?

http://www.firebladeautomotive.com/s...mart&Itemid=26
http://www.firebladeautomotive.com/s...mart&Itemid=26

It's their own.
Same general design as the others I've listed in the earlier post. You can tell by the dogs and ramps along the centerline.

http://www.firebladeautomotive.com/s...4e2388c5a0.jpg

The Quaife is suited for high traction circumstances, where you want to make it harder to break traction. (Like drag racing with slicks, or tracking but not lifting the inside up off the ground in turns.)
It's not made for sliding around on snow or wet/slippery surfaces (like in the video that I'm sure you have in mind.)

The Hartage (and the others on the earlier list) are made in a way that allows for minimum lock (preload), so they work no matter what the surface.
They also lock more as you apply power, even if the wheels are spinning (albeit less than with traction).
But they also lock when you dont need them to lock... like when you're turning and you are nowhere near spinning a wheel. Which is when you get the understeer effect.

-scheherazade

[dlbrooks18]

Originally Posted by scheherazade

http://www.firebladeautomotive.com/s...mart&Itemid=26
http://www.firebladeautomotive.com/s...mart&Itemid=26

It's their own.
Same general design as the others I've listed in the earlier post. You can tell by the dogs and ramps along the centerline.

http://www.firebladeautomotive.com/s...4e2388c5a0.jpg

The Quaife is suited for high traction circumstances, where you want to make it harder to break traction. (Like drag racing with slicks, or tracking but not lifting the inside up off the ground in turns.)
It's not made for sliding around on snow or wet/slippery surfaces (like in the video that I'm sure you have in mind.)

The Hartage (and the others on the earlier list) are made in a way that allows for minimum lock (preload), so they work no matter what the surface.
They also lock more as you apply power, even if the wheels are spinning (albeit less than with traction).
But they also lock when you dont need them to lock... like when you're turning and you are nowhere near spinning a wheel. Which is when you get the understeer effect.

-scheherazade

Thanks man for the knowledge!

[scheherazade]

Now THESE are what we should have...

Hear are the rear diffs from an evo 7 and 10
Notice the torsen-type core, WITH clutch pack!
(pics are labeled funny for the evo 10, but it's obvious which diffs they are looking at em')
http://image.superstreetonline.com/f...fferential.jpg
http://newzmaker.files.wordpress.com...erential-a.jpg

Check out this awesome center diff...
http://newzmaker.files.wordpress.com...-control-a.jpg

*jealous*

-scheherazade

[kenneth]

Originally Posted by scheherazade

Now THESE are what we should have...

Hear are the rear diffs from an evo 7 and 10
Notice the torsen-type core, WITH clutch pack!
(pics are labeled funny for the evo 10, but it's obvious which diffs they are looking at em')
http://image.superstreetonline.com/f...fferential.jpg
http://newzmaker.files.wordpress.com...erential-a.jpg

Check out this awesome center diff...
http://newzmaker.files.wordpress.com...-control-a.jpg

*jealous*

-scheherazade

What do these do? and how much approximately?

[uberschnell]

That's what I love about the quaife, it still provides that margin of safety, I mean who would want to risk breaking the outside wheel loose if you have managed to lift the inside wheel that much off the ground? Note: you can get the oem diff to spin light years sooner and far longer then you could any quaife equiped unit.

[leftcoastman]

As a quaife equipped track guy, I have to say that the fears about the quiafe are probably overblown.

I have done over 50 days on track...with a quaife. If you made the mistake (like me) of upgrading your anti-sways, you will get inside wheel life and maybe cause some some open diff like behavior.

However, after 6 different tracks, the stock quaife and a coilover suspension system has proven to me that the quaife is absolutely phenomenal on track. I have NEVER gotten inside wheelspin since getting my quaife.

[O-cha]

Originally Posted by Mr. 5

So, no ring gear swap?
I'm still confused with why we can't get a ring and pinion, bolt the ring gear to the LSD and then install it into the diff.

Answer your own question. Why can't you, because no one (including BMW) sells them. /thread