<VV> early suspension changes question

[Joel McGregor]

I guess you've never seen any early autocross pictures?  Jacking with swing axles is very real.  My earlies tend to wear the sidewalls on the rear tires and my lates don't.  Why would that be?  The transverse leaf actually does nothing to resist body roll.  It was designed to increase spring rate without adding any roll resistance so they could use softer main springs to reduce jacking.  I haven't read or seen Nader's book.
Here's a site that has a picture about a third of the way down the page.  I don't agree with the explanation but the jacking is obvious.  He claims that jacking only occurs when the car is upset but I know that it can easily occur just from hard cornering.
Joel McGregor
(I may be unsafe at any speed)

________________________________________
From: virtualvairs-bounces at corvair.org [virtualvairs-bounces at corvair.org] On Behalf Of Ken Pepke [kenpepke at juno.com]
Sent: Monday, September 19, 2011 1:40 PM
To: Vair Views
Subject: <VV>  early suspension changes question

I am sure you would find the GM produced movie 'Car on Trial' most interesting.  Seems like everyone looked at the book 'Unsafe At Any Speed' and saw the 'tuck under' pictures then accepted his explanation as gospel.  The GM film includes segments of an early model suspension working on a skid pad and generating something over .7G, as much as the engine was able to produce.  It established Mr. Nader's 'tuck under' theory as fallacy.

While you are correct in saying the transverse spring does not locate the wheel you have assumed I said something that I did not.  The mechanical roll center remains as designed but as that spring acts as a quasi roll bar it lowers the apparent roll center.  It reduces the amount of body roll.  The average driver will read the reduced body lean as 'improved' handling.

As Mr. Nader's 'jacking' does not exist in the first place there can be no assumption of performance modification, either positive or negative.

Ken P
Wyandotte, MI
Worry looks around; Sorry looks back, Faith looks up.