Date: Sun, 4 Nov 2007 20:00:18 -0800
Reply-To: aatransaxle <daryl@AATRANSAXLE.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: aatransaxle <daryl@AATRANSAXLE.COM>
Subject: Re: limited slip on ice and snow
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No doubt that the clutch style LSD works better...all agree on that. Yes
there are some limitations to the torque biasing style we are "forced" to
use...still waiting for more tales of the ATB (torque biasing gear style)
style and its improvements to the stock open diff...And remember the key to
slickery driving is a light right foot above all else....Have a good week
all.
Daryl of AA Transaxle
(425) 788-4070
aatransaxle.com
----- Original Message -----
From: "Don Hanson" <dhanson@GORGE.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, November 04, 2007 7:29 PM
Subject: limited slip on ice and snow
> 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
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