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Defining CG Location(1)

To: "land-speed submit" <land-speed@autox.team.net>
Subject: Defining CG Location(1)
From: "3liter" <saltfever@comcast.net>
Date: Wed, 30 Jun 2004 18:24:57 -0700
No one will dispute how important it is to know the vehicle CG location.  As
Jack and others have mentioned lately, it is critically important for the
chute attach point.  The CG is really the pivot point the vehicle rotates
around, and applying any force (e.g., the chute) not directly though it, is
unstable.



Using the engine camshaft location as one of the locating coordinates may
not be a good choice nowadays.  It was useful 40 years ago when drag racers
discovered "weight transfer" and 99% of the engines were American V-8s
(Ford, Chevy, and Chrysler) and their cam position was very close to the CG.
I checked this once by suspending a SBC (3 different ways) and the CG of
that engine was almost at the camshaft location.  So it was a good yardstick
to use for an SBC.



However, in LSR there is so much else to consider, generalizing on the
camshaft location can be dangerous.  With the myriad and diversity of engine
styles and configurations (DOHC, flathead, straight, L, and V, etc.)
focusing on the cam location is not a good idea.  Most importantly, ADDING
BALLAST will drastically change the car's CG. In fact, since ballast is
usually added very low in the car, the CG location will be LOWERED.  And
that is the reason for my question on the next posting.  -Elon






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