cf

[QSHIPQ <QSHIPQ@aol.com>]

Dave E.:
Locked center, Trg = 300, BR 50/50 split = 1:1
T1 = 150
T2 = 150
Tshift = 0
Trg = maximum

T1 = 1
T2 = 1
Tshift = 0
Trg = 2
Trg = min
Pick a number ANYWHERE inbetween
T1 = 50%*Trg to the ground

Torsen 75/25/25/75 BR = 3:1
T1 = 225
T2 = 75
OR
T1 = 75 
T2 = 225
Tshift = 150
Trg = max

T1 = 1
T2 = 3
OR 
T2 =1
T1 = 3
Tshift = 3
Trg = min

In straight line acceleration that is advantage Torsen.  PER my own posts.

Turn, that changes things.  Why?  Because you shift torque in a torsen car,
specific to the 300lb/ft car, 150 lb/ft of it.  In a locker, you never shift
any.  The Trg reduces, and the car understeers with the same torque all the
way thru the turn.  You lift a wheel, total torque to the ground reduces 50%
f/r in relation to each other.

A Torsen OTOH, can sense driveshaft rotation slowing in relation to the front,
and transmit 100% Tshift to the other axle given the right circumstances with
NO loss of actual traction.  So Trg is max, traction is max, but Tshift is max
as well.

What is that point?  I don't know, I know this, it's there, it has to be.  90
degrees of slip with NO power is a STOPPED rear wheel.  90+ degrees is a
reverse rotating wheel.  What's the difference?  Torque.  So, AT a given cf,
with a given slip angle, the torsen will transfer maximum Tshift while
accelerating.  When you go on the gas, and the rear driveshaft rotates faster
than the front (not a traction problem), you transfer Tshift max to the front.
Until a tire breaks free, you haven't decreased Trg to the ground.  I also
argue that the slip angle needs to be NO where near 90 degrees for this to
happen, btst.

I am frustrated by this discussion.  Why?  Jeff and I have not argued
anything, just presented physics.  And we aren't saying that torsen is a bad
thing, and it's a GREAT thing in terms of absolute traction in a straight
line.  We've experienced it's dark side, and we haven't mastered all the
variables of it yet.  I'm not convinced we will.  However, reiterating math,
is silly to me, it's in the paper presented.  Dave, you need to understand
what the difference is between wheel lift and slip angle, in relation to a
center diff vs a fwd/rwd diff.  You need to understand what the difference is
between Trg max, and Trg min, in relation to traction on a locker.  In a
center diff, BR isn't necessarily traction, it CAN be slip angle.  In a locked
diff BR is the same always, the only thing that will change that absolute
traction, but that change reduces overall Trg only.  Why?  Cuz you can't shift
the torque split.  You only reduce Trg to the ground.  When a locker goes to
the same slip angle, 150 goes front 150 goes rear, all the way thru the turn.
Or a wheel loses traction and the T1 + T2 = %*Trg.  But power, in terms of
absolute torque to the f and r traction is a CONSTANT.

With a torsen, that is not true anymore.  Why?  Because torque CAN BE in
relation to driveshaft rotation ONLY, not necessarily traction.  It CAN be in
relation to traction, my only argument has always been it doesn' t HAVE to be.
By the definition of a center Torsen of "traction".  Slip angle on a locker is
a constant, on a variable split, slip angle becomes a variable, to the
operation of a torsen.  IN absolute terms of traction and torque slip angle is
a traction issue.  In reality that is exactly NOT what is happening, yet
torsen is correcting for that exact non traction event.

I'm not sure it can be made more clear, my hardrive is begging for relief.....


Scott