Date:    Thu, 2 Jan 2003 08:32:00 -0700
From:    Ben McCafferty <ben@VOLKSCAFE.COM>
Subject: NVC:  Eurovan traction/stability control

<snip the original for brevity>

Just a few clarifications. The system is called ESP, is made by Bosch and is
the same system available in BMW and (I think) Mercedes.

There is no active suspension control on the VW. Just big honkin' sway bars.

The system does not activate both front and rear wheel brakes at the same
time. In the case of your expample, in a left turn the system would activate
the left rear wheel if understeer happens. If you look at the mechanics of
leverage, you'll see that this is more than effective, as it pulls the
center of gravity using the leverage advantage. The front tire braking
during understeer would not have nearly the same leverage, and could even
contribute to more understeer. In the case of oversteer in a left hand turn,
the right front wheel brake would be activated, encouraging the front end to
plough and eliminate the oversteer. Obviously, the system self corrects many
times a second, and consults a gyroscope for attitude, so over correction is
impossible.

And as the owner of an EV with ESP, I have to tell you this setup works.
It's spooky at first. It's amazing on wet roads, and an absolute requirement
for snow or ice.

Luckily there's a switch to tuen it off when you want to have fun, because
when it's on the van doesn't do anything but go where it's pointed.

Az
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AH#56