Locking Torsen

[Orin Eman]

> 
> 
> 
> On Thu, 14 Dec 2000 12:39:08 +0100 (MET) Jens =?ISO-8859-1?Q?R=F6sner?=
> <jens.roesner at gmx.de> writes:
> >Hi Lawrence!
> >
> >I have posted some kind of FAQ dealing with all that some weeks ago, I
> >hoped this was not CWOB...
> >
> >> Any Quattro (not including the TT) is full time all wheel drive
> >And not including the A3/S3: All "quattros" with transverse mounted
> >engine.
> >BTW: The Haldex is IMO between full-time and part-time, I don't want 
> >to
> >revive that discussion.
> >
> >> is full time all wheel drive, which 
> >> means that approximately 50% of the torque is directed to one front
> >axle,
> >> the other 50% is directed to one rear axle. 
> >As long as there is no serious slippage on the axles.
> 
> True - that's why the approximately. It's only certain to be 50/50% when
> quattro1's center diffy is locked
> 
> 
> >> Any non-limited slip front or
> >> rear drive car has approximately 100% of it's torque directed to one 
> >of
> >> the two driven axles 
> 
> Was trying to figure out how to say that without adding too many
> sentences.....
> 
> An open diff RWD car will direct approximately 100% of the engine's
> torque to one rear wheel, especially in a slippage situation.
> Unfortunately, the wheel that gets that 100% is the wheel that is (or
> will be) slipping. 

Here we go again...

With an open diff, the ouput torque is always the same on each
output shaft - ie the distribution is 50-50.  A locked diff can
transmit up to 100% torque to one axle.  (You have to draw the
force diagrams of the open diff to understand the 50% to each axle.
Essentially it's an application of "for every action, there is an
equal and opposite reaction".  The reaction of one axle against
the diff pinion gears provides the action that drives the other axle
and vice-versa.  This means that each axle is driven with the same
force at the same distance from the center of rotation and hence
each receives the same torque.  Things get a little more complicated
when you add in accelerations, but the torque distribution remains
the same.)

Power is different.  You can get 100% power going to one axle
with an open diff if the other axle isn't turning (power is
proportional to torque * RPM, so if RPM is 0, power is 0).

Orin.