<VV> early suspension changes question

[Ken Pepke]

I received no 'site.'  But I have seen pictures and I have been there in person.


Now you are talking about a whole different situation.  Virtually any car will 'jack' on the outside wheel(s) and even roll over if the driver or the road surface does something to 'upset' the vehicle under near maximum cornering.  But it never 'just happens,' there must be some other force than cornering force applied.  One might argue that it happens to a Corvair easier and/or faster than other contemporary cars but a new light is shed on that when one comes to realize the Corvair is moving a lot faster than the other cars of its day.  

The softer rear spring reduces the percentage of roll resistance at the rear and increases the percentage of roll resistance at the front axle so as to reduce the tendency toward oversteer.

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

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On Sep 19, 2011, at 4:10 PM, Joel McGregor wrote:

> 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.