Date:         Sun, 31 Jan 2010 21:24:21 -0500
Reply-To:     Kim Brennan <kimbrennan@MAC.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Kim Brennan <kimbrennan@MAC.COM>
Subject:      Re: Snow, 4wd vehicles and syncros
In-Reply-To:  <e3ab8df33c2f6b29af16a07c2a48251b.squirrel@hasenwerk.homeip.net>
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Not my experience with my Syncros. Perhaps I don't drive like you. I have done one emergency maneuver with a Syncro, at highwy speeds (roughly 100kph, 60 mph). Vehicle in front of me (miata) spun out. I swung out of his lane, on to the shoulder, and then around him. I'm sure without the syncro traction I would have spun out on the shoulder or median.

The side roads (what I was travelingon) here in Northern Virginia (Tyson's/Great Falls area) are twisty, not particularly well banked, with little if any shoulder.

Of course, I automatically drive differently in snow than on drive pavement (give myself more space, prepare for turns a lot further back, etc.) Not all folk do (and the consequences are evident by the SUVs in the medians, and the interesting donut patterns in the snow at intersections.)

The thing most folk forget when driving 4 wheel drive vehicles, is that the drive train is great for getting moving, but braking and turning still rely on the same principles that affect 2 wheel drive vehicles. Newton's first law of motion.


On Jan 31, 2010, at 1:52 PM, David Marshall wrote:

> 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.