Re: Differential Locking vs Driving style

[Glen Powell <gpowell@acacianet.com>]

At 02:00 PM 2/8/96 -0500, PDQSHIP@aol.com wrote:

>........  Coming from a prorally background, as well as road racing, can
>share this:  If you NEED to lock the diffs on a 4kq or a urq on a dry track,
>some serious looking at the chassis might be in order.  Specifically, SPRING
>height, Spring weight,roll angle, ackermann effect, Chassis dynamics, and
>driving style....  I assure you, glen, High HP does not lend itself to your
>proposed style, BTDT....  If you are driving that way and getting BETTER
>times, you have a CHASSIS problem, look hard at where and why.....  If you
>don't want to correct it, you are correct in your assessment.  However,
>putting/making up with/for design compromises should not be a goal, but a
>target for improvement....
>

It's not a question of not *wanting* to correct it, it's a question of
SCCA *Solo II autocross* Stock Class rules specifically prohibiting all
those types of mods, and therefore adjusting the very few things that are
not specifically prohibited, struts, tires and driving style. We're not
dealing with Prepared road-race type rules here, this is Solo II Stock Class
stuff.

>A properly suspended quattro, should not LIFT it's inside wheel, which is the
>only reason you need to lock the rear diff......

Lift never, spin *yes*. However, I believe that with the rear diff locked it is
easier (for me) to overcome the inherent understeer of the 4KQ with the
throttle, even in cases where the inside rear wheel is not spinning. Sending
torque to both rear wheels makes it a lot easier to balance under/oversteer
with the throttle Vs just plowing along and killing lotsah innocent cones
and keeping the course workers busy. I did enough of that in my V8 days!    :)

>   Tossing a q into a corner
>properly without the rear diff locked, will still give you throttle on
>oversteer (at hi hp), 

No high HP in *my* '84 4KQ!        :(

>as well as lift throttle oversteer.  The stock setup on
>the q's is initial understeer, and lift throttle oversteer.....  Both Eric F.
>and I use the open diffs on all tracks to date, and dragging a 100% rear
>locked diff around the track is proven nowhere in racing, especially on a
>road course......  

Road course is *very* different Vs SCCA Solo II. We're talking apples and
basketballs here......
      
>No offense intended to Glen or Steve, if it works for you
>go for it.....   Is it THE method for gaining speed, not in engineering or
>practice.....  Look hard at that suspension, make the changes to make the
>chassis right, then forget locking the diffs till Steamboat arrives next FEB,
>or maybe in the rain at a road course....  I might encourage a look at the
>center lock if you have traction prollums, but since my car is in the 350+++
>mark with none, again I would encourage proper setup vs locks, I have yet to
>spin a tire on a dry trackwhile on line, so the why question comes to
>mind....
>
>A driving course with proper instruction, properly executed racing lines are
>not rocket science, they are there, regardless of vehicle, what awd does to
>that line is only on the exit of a turn on full throttle.....  If you are
>doing it any differently, a couple of rides with Eric might be in order......

I would take you up on that in a second!

Again, we're talking Solo II here. I've got some relatively *small* amount
of road-race experience as well, and both diffs open has always worked best
for me, even in the wet, so I hear yah! I have been autocrossing for 16
years and 4 in Quattros, inlcuding a NER HS Championship in the 4KQ, so I
think I have a fair handle on 4KQ auto-x setups and chassis/suspension
limitations and how to "drive" around them. I get an easy second very
reliably with the diff lock on all auto-x courses I've run on. Auto-x ain't
road-racing!

>   NJTH
>
>Scott

BTDT2,

-glen