Date:         Sun, 4 Nov 2007 19:29:49 -0800
Reply-To:     Don Hanson <dhanson@GORGE.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Don Hanson <dhanson@GORGE.NET>
Subject:      limited slip on ice and snow
Content-Type: text/plain; charset="Windows-1252"

  My experience duplicates the fellow with the nadar-Mobile from Bend.  Let
up  on the gas and the vehicle catches itself in an 'Oversteer situation"
Simple and predictable

...Caution:  Do NOT try that in a Porsche rear engine or a VW rear
engine...Once the rear end of one of those gets moving to the outside of a
corner, letting off the gas is the exact wrong thing to do because as the
car starts to decelerate from no throttle, it shifts the weight to the front
wheels and lets that big weighty back end slide around even more quickly.

 At Portland International Raceway road course, there is a dip mid corner at
a fairly high speed section where everyone is accelerating like crazy onto
the back 'straight'..It's called "The Porsche dip" because as those
(rear-engined ones only} hit the dip and step a little out, their drivers
freak often and let off the gas very quickly(you learn to drive like that in
a 911, I guess)..that puts them slightly sideways with their steering wheels
trying to catch up to the back end...But then.....they come down hard on the
other side of that dip, regain traction..pointed wrong..and quite often they
back, quite hard,  into the inside(! ) concrete retaining wall...there is a
great Porsche factory color sample chart of paint on that wall...

  I know with a clutch type LSD you can adjust the bias and also influence
how much transfer you have between the wheels by using different
differential oils..My Porsche 928 had this traction control system from the
factory called PSD, which was essentially hooked into the ABS sensors for
wheel speed and used a very high pressure hydraulic system to direct the
traction to whichever wheel needed it...Great for going on a hill..but awful
at the racetrack.. I retro-ed a clutch pack limited slip and all was good..

  Seeing you soon, Daryl at AAA transaxle...

  Don Hanson