Date: Sun, 31 Jan 2010 23:17:45 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Snow, 4wd vehicles and syncros
In-Reply-To: <e3ab8df33c2f6b29af16a07c2a48251b.squirrel@hasenwerk.homeip.net>
Content-Type: text/plain; charset="iso-8859-1"
If you really get past the myths what you are saying really is not true.
Power really goes to both front and rear axles and when there is a
speed/torque difference the VC allows for the difference. As the difference
continues the torque or resistance to the different speeds increases. Now
here is where you can get some complicated dynamics. During a turn the front
wheels have to roll further than the rear so at some point the ears will get
driven faster if they can slip.
I have an Audi A8 Quattro and it is great in snow. However the center
differential is limited in how much torque can go to the rear. It really is
a front drive with a lot of rear wheel assist. Some of its snow performance
is due to it being a great handling sedan to begin with.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David Marshall
Sent: Sunday, January 31, 2010 1:53 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Snow, 4wd vehicles and syncros
You need to drive an Audi quattro... ich liebe mein A4!
The
problem with a correctly working syncro is that just driving along it is
only a 2WD. It will be a 2WD *until* there is a difference in speed
between the front and rear wheel speeds. In a correctly working
system will take about 1 or 2 wheel revolutions for the VC to fully
engauge and the vehicle will become a 4WD.
Now, take a 90deg
intersection at 50 km/h like you would in the dry only cover it in ice and
then a layer of snow on top of that. Do it in a Syncro and then do
it in a quattro. With the Syncro you will have the back end come out
because those wheels are going to spin while the fronts do nothing other
than get slowed down by the snow. One the rear wheels start spinning
you will start to loose control. In effect you better be quick or
else you will get into a horrible spin. With an all wheel drive like
the Audi quattro it is always 50/50 front and rear so one end won't spin
even for an instant faster than the other end. The older Torsen
diffs would pull power away from the wheels that want to spin and the
newer electronic systems do the same as well. The new Subarus are
pretty good too!
Not sayign the Symcro is bad, just that there
are better much 4WD systems out there!
David Marshall
VW
Adventure Driver and BMW Adventure Rider
HasenWerk
http://www.hasenwerk.ca
On Sat, January 30, 2010 23:04, Kim
Brennan wrote:
> So the Washington DC area got the snow I
predicted earlier in the week
> (helps to have good weather
models...and then to trust them.) About 6
> inches in my immediate
area (Tyson's Corner, VA, on DCs western side.)
>
> I had
some errands to run and headed out in my Jaguar X-type (manual
>
transmission, all wheel drive.) I've got some Vredestein severe winter
> rated tires on it (less than 3000 miles on them. Didn't really have
any
> trouble, but (as I had noted earlier with this vehicle) the
majority of
> the power goes to the rear, and in turns it is not
difficult at all to
> break the rear loose from the road. Mine is
a 2002, which uses a Viscous
> Coupler (later they went away from
that.)
>
> I then stopped in at the house and changed
vehicles to my 91 Syncro
> passenger van (non-GL, with an SVX
engine). This vehicle as the Nokian
> tires
>
>
Uh. Night and day. While the Jag is competent, the Vanagon Syncro is
> otherworldly. Never had trouble, even in turns, same set of roads
too.
>
> I love my Syncros. :)
>
