Let's talk about quattro driving in the snow

[Dave Hord]

Originally I was going to stay out of this...but now I figure, what the heck.

First off, I'm not a driving instructor.  Secondly, I'm a self-taught auto
enthusiast who rallies and solo II's.  I've been doing it for 5 years, fairly
solidly. I've learned from some of Ontario's best, when we've jumped in each
other's cars at rallycrosses and the like. So, while I'm not an expert, I have
a fair amount of experience as well. In terms of rallying/solo II I have a LOT
to learn, but in terms of safe street driving...I've pretty well competent.

Brett makes some good points, and some points I disagree with.  I'll try to
outline using a minimum of space:


> > <snip><summary> and understeer happens <snip><end summary>

> > Actually, it's a lot better than the alternative(oversteer.)
> > Understeer is what happens under power, and it's usually easier to
> > correct in a FWD or quattro, because in both cases, your instinctive
> > reaction(get off the gas to 'slow down') is a good thing.

Understeer isn't a 'power-on' phenomenon.  Understeer occurs when you go 'too
hot' into a corner. This could be with power on, or power off.  If you're
traveling too quick into a corner, the car will initially understeer. Depending
on how you try to save it, it can understeer, oversteer, become neutral
handling or just snap out of control...

In terms of chassis dynamics we can refer to many different 'characteristics'
including; power-on oversteer, power-off oversteer, power-on understeer, power-
off underteer, as well as 'neutral' handling under a variety of conditions.

Brett's comments reflect a belief that you entered the corner with the gas on,
and experienced understeer (power-on understeer).  In that case, he is correct
that your best course of action is to lift off the gas to transfer weight to
the front wheels.  For now we will assume that it wasn't an emergency
situation, and lifting the gas will result in a safe completion of the turn.

On to more!

> > <Original Lister>
> > >I've driven both fwd and rwd cars in the snow. FWD will lose the
> > >front, but a quick pull on the
> > >emergency brake will swing the rear around.
> >
> > <Brett> Pull the handbrake, and now you've lost all FOUR wheels :-)

Okay...this is both a 'yes' and 'no' answer.  Yes, pulling the e-brake will
often pull this around.  But NO, this is NOT the best solution!  E-brake use
should always be limited to EMERGENCY situations, in a "oh shoot I'm going
to..."  Using the e-brake is not the correct/fastest/or safest way through a
corner.  "_E_-Brake".  Emergency only.



  <Sean>
> I disagree. [to brett saying don't use the e-brake]
> If a fwd car is heading straight through a corner, with the
> front wheels turned, the rear wheels are just along for the ride, neither
> helping or harming. With a sideways slide, in the direction of the corner,
> the rear wheels are more like rudders than simply supports for the rear of
> the car. Think more along the lines of rallying and less along the lines of
> out-of-control. It's the out of control aspect that I'm trying to avoid.

The rear wheels actually don't work like rudders...and you have to be careful
here...if the rear wheels 'catch' you can flip it pretty quick...ESPECIALLY if
you've pulled the e-brake.  Why? 1) the rear wheels have locked for an instant
and are no longer 'rolling' over the ground. 2) The entire car has lost
momentum, and now gravity becomes a major player again, pulling the car down
(as opposed to centrifugal (sp?) forces 'pulling' the car across the road
surface).  Rally drivers, who routinely spin sideways are NOT using e-brakes!
Again, emergency use only...e-brake slows the car, and increases your 'roll'
potential.


> > >Once I lose the front with quattro, what is the best way to rotate the
> car?
> >

<Brett>
> > You shouldn't be thinking of 'rotating' the car(angle doesn't get you
> > around corners, GRIP does), you should be thinking about regaining
> > control(ie, get the car pointed the way it's travelling) and stopping
> > if necessary.

I agree...if you've 'lost' the front in the quattro, you screwed up your
manuver earlier...NOW your job is to get the car back under control. The best
method to do that is the following:

1) lift off the gas, steer where you want to go.
2) if that doesn't work, apply the brakes LIGHTLY
3) if the car is still not turning, consider your exit points for an
emergency...more on this in a moment.

<Sean>
> Maybe I'm missing the point, but in my mind, having 4 sliding and powered
> wheels pointing at the exit of the corner is advantageous. 2 sliding
> powered
> wheels pointing at the exit and 2 non-sliding powered wheels pointing
> straight
> ahead sounds like a recipe for disaster. I really feel like I want to
> rotate
> the car, lifting off the throttle might be the answer or it might just leave
> me
> in the sliding situation until I hit something solid.
>

Sean, I think you're thinking about 'performance' driving through a corner,
using a 'rally slide' technique.  Brett is talking about fixing an "I screwed
up and now it won't turn" maneuver.

However! The answer for SAVING the mistake has nothing to do with where the
rear wheels are pointing...it has everything to do with where the weight
transfer is...when you lift off the gas, and steer in your chosen direction,
it's very possible that the rear-end might swing around into an oversteer
position...but it doesn't matter...you (behind the wheel) keep the front wheels
pointing where you want to go.  If the weight transfer is on the front wheels,
you have steering ability...THAT'S the important part.

Okay, here is where Brett gave two reasons why you don't e-brake, keep it going
straight and try and bleed the speed off. In summary they were: (Brett will
correct me if I miss summarize!)

a) The car is best designed to absorb impacts from the front...not the sides.
Your seatbelt/airbag, crumple zones etc. ALL work BEST (read best chance of
saving your LIFE) from a front end impact
b) Keeping the car and tires straight gives you teh best option of finding some
traction and BLEEDING OFF SPEED...thus lessening your impact. He then used
Chris Miller's watkins glen experience as a demostration.

First off, Brett you're totally correct about the impact zones.  You're also
fully correct about the stay straight and bleed speed...but only on dry
pavement/track conditions.

We were discussing snowy conditions...where a NUMBER of variables come into
play.  Snowbanks? Other cars? Trees? Buildings? blank 'nothingness'? A ditch?

With any loss of control situation you must be able to quickly evaluate what
your best option is.  For instance, if there are snowbanks that I know to be
generally 'soft', I'll go for the e-brake, induce a sideslide into the bank.
The back serves to stop the car.  If I went straight in, the car goes through
teh bank into the woods.  How do I know?  Last rally from teh Yokohama Winter
Rally series last year.  But even in the case of a snowbank, you have to
quickly assess if it's the best solution.  I had a navigator in my car. Sliding
sideways meant that I was putting him sliding towards the woods. There was a
big tree, that if the car went through the bank, we would have hit.  I had to
decide (in a split second) that the risk of hurting Mike was too high..thus I
went straight into the woods.

REGARDLESS of all this.  There are three situations the thread deals with:

1) What to do in an emergency understeer situation on snow.
2) What is the best way to get through a corner, with quattro, in the snow
3) Ignoring perhaps the 'safest' way, how does one have FUN in a corner with
quattro, in the snow.

Wow this is getting long.

1) Lift off the gas, steer where you want to go. If that doesn't work, apply
LIGHT braking, steering where you want to go. If that still doesn't work,
assess the situation (hopefully you've done so already)...is it safe to try and
spin the car? What would you hit? is the SAFEST bet just to go straight?? If it
seems logical to try to spin the car, keep the wheels turned apply slightly
more brake (transfering weight to the front) and pull the e-brake to spin the
car.  STEER where you want to go! the car MIGHT oversteer resulting in a
serious need for hand-over-hand!

2) The BEST way into and out of a corner in a quattro is the following:  a)
SLOW DOWN before the corner while you still have plenty of room and traction.
b) start the corner like grandma does, at a slow speed. c) apply gas at or just
after the apex...slowly, and smoothly.  You'll never get in trouble if you (as
was previously said) "go in like a lamb".

3) Short answer: take a winter driving school.  Longer answer: Left foot
braking, pendulum turn, serious rally style corners.  DON'T try them on open
roads! Take a driving school!!! (since no-one really listens to that...maybe at
some point we can start a thread on how to try it..in a snowy parking lot with
no cars around).

Am I done!?!

I think so.

-Dave

---------------------------------------------------
89 90q  300km+ Rally Conversion...
Roll cage shots available at:
http://home.the-wire.com/~spokes/rollcage/page1.htm