Diff talk, S1 &Hannu Mikkola, Buffum

["Scott Mo." <scottmo@teleport.com>]

Here is some S1 differential info from the July 1986 issue of
"Automobile" to fuel the Torsen vs regular diff. fire.

Audi S1 Quattro, Hannu shows us the woods: By Mel Nichols

"For a week, Hannu, Dieter, Willy, and three more mechanics have been
developing the S1 Quattro as part of the program for the 1986 rally
season. <snip> They've spent days on one of the most difficult tasks of
all - evaluating new center and rear differentials, which split the
torque to the front and rear wheels in various ways and lock up with
different degrees of progression. At the level of sophistication that
four wheel drive rally cars have now reached, this split and this
progression are crucial to handling and balance, not just grip. Working
painstakingly, logging and comparing the results through Dieter's little
computer, they decide first on the center diff and then after another
two days work, the rear diff. The mechanics are so adept that they get
the diffs in and out and send Mikkola off on another blistering circuit
within twenty-nine minutes. At last, Hannu is happy with the handling.
As we finish our circuit and trundle back to base, he says: "The balance
is very good now. I can start to go very fast."" <snip> 

Hannu says: 
"Because the layout of the S1 Quattro is so similar to that of the road
Audis, I also like to know that the work were doing is valuable to
customers. This is a very quick way to develop new systems and
components. If we can use them in the production cars, it justifies the
money we're spending. One of the new differentials we've been developing
is likely to go into other Quattros."

In the Oct. 1983 Car and Driver magazine, the Pikes Peak car that John
Buffum drove is highlighted. The specs page shows the engine as a
2144cc, 6:3 to 1 compression ratio, 20.3 to 24.7 psi boost, Pierburg
mechanical fuel injection, 340 HP@6500 RPM.

5 speed transmission, Final drive ratio 4:88 to 1 (Limited Slip, rear)

Your torque distribution and mileage may vary.....
-- 
Scott Mo.
1989 200TQ
http://www.teleport.com/~scottmo