Re: Center diffs [was RE: 325ix vs. Quattro]

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Wed, 2 Apr 1997, Steven Buchholz wrote:

> My understanding is that the 959 uses computer controlled clutch packs to 
> determine the F-R torque split.  I have heard that the automatic tranny/
> center diffs on the V8q also had this sort of an arrangement.  It seems 

I heard that they used Torsens, but I'm not the expert in this regard (or 
any for that matter!) :-0

> to make sense, as the tranny already has a separate control module to 
> do the shifting ... it could probably sense whether front or rear was 
> getting better traction.  Can anyone confirm that the V8q's box had this

In order to sense front/rear traction differences, they would need to have
additional speed sensors on each output shaft of the centre diff.  Then a 
computer could determine if either front or rear was slipping, and then 
tighten up that end.

	Did anyone see the diff that Nissan is working on?   It has a 
fluid pump between the two rear axles, and any slip causes fluid pressure 
to build up, which is used to clamp the clutch paks together.   Sounds 
interesting.   It seems like it would be easy to calibrate, but may still 
have most of the disadvantages of a clutch-type LSD.

Later,
Graydon D. Stuckey 
'86 5KCSTQ, GDSstageIII
"No, its our family car."