Re: Car physics: was MK1 Drag results...

[Goethfaust@aol.com]

In a message dated 05/18/2000 9:10:26 PM Eastern Daylight Time, 
sfwilliams@home.com writes:

<< ncorrect, the center of gravity changes from front to rear only with 
ballast movements. Raising the
 rear of the car does not move the cg up towards the front wheels at all. 

I've sort of been following this thread, and I don't think it was ever said 
that raising the rear would move the cg forward, just raise it vertically.  
That said, raising the rear corners equally would transfer weight to the 
front, if for no other reason, gravity.  Yes, if you raised the rear, weight 
transfer to the rear would be increased during forward movement, but only 
because that weight was displaced to the front by raising it.  Isn't weight 
transfer in this case reduced by an unforgivingly suspended car?  
 
 <<Ask a road racer about weight jacking. You know those height-adjustable 
coil over kits that people
 think look really cool? Well, their legitimate purpose is to transfer weight 
around to achieve a closer
 to ideal load distribuition. The old axim is "lower is lighter; higher is 
heavier". Since weight  moved
 farther (vertically) from the cg increases the moment, weight transfer is 
thusly *increased* towards
 the direction that the chassis is moving around the fulcrum -rearwards. >>

Isn't this corner-weighting?  As I understand it, a car is corner weighted 
diagonally, RF+LR, etc.  If you raise the RF, it reduces the weight on the LF 
and the RR.  The same as when you jack up only one corner of your car.  The 
other corner on the same side comes off the ground.  The effects of higher is 
heavier do not unilaterally apply, when raising one end of the car, I don't 
think.  

I don't claim to be an expert, but this is a subject about which I am very 
interested, and my understanding of it greatly differs from your explaination.

cheers

Greg Faust

88 16v Scirocco DSP
87 GLi
86 Jetta 2-dr "GLi"
91 GLi
53 Hudson Jet

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