[Biturbos4] Wheel spin - Thread Hijack - Wheel Spin

Ti Kan ti at amb.org
Thu Apr 14 00:28:35 EDT 2005

j y writes:
> With the current thread - I guess we've found some more marketing
> hype about Quattro versus fact. Anyway, my tech found out something
> very interesting about the Quattro system on S4s when he removed my
> driveshaft. Going under the assumption that a true AWD car will still
> provide power to the front wheels when the driveshaft has been removed,
> my tech found out that this is not possible in the S4. No, in my tech's
> observation, the Quattro system on the S4 is rear wheel biased. If
> the driveshaft connecting the front and rear wheels is removed, then
> there will be no power transfer from the rear to front wheels, and the
> S4 will not operate like FWD car (as he expected), with the connecting
> driveshaft removed . He observed this with his own eyes. According to
> my tech, the S4 is not a true (fulltime) AWD car. Might help explain
> why the original poster could not move forward when his real wheel stuck.

The Torsen center diff is located within the main gearbox, so when you
disconnect the driveshaft to the rear, you unload the output of the Torsen.
If you understand how a Torsen works then you'll know why the car
behaves the way it does when you disconnect that driveshaft.  However,
to say that the car is not full-time AWD based on this phenomenon is 
simply incorrect.  To say that the B5 S4 is rear-biased is even more

Ti Kan
Vorsprung durch Technik

More information about the Biturbos4 mailing list