
08-26-2015, 12:05 PM
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Join Date: Nov 2008
Location: Thompsons Station, TN
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Quote:
Originally Posted by Ron Sutton
It is/was pretty common to set-up a car low, with the crank centerline (at the balancer) at 12" above ground "to get the mass low". Then with a stiff front spring set-up, the car may travel (compress) 1" ... so this mass is 1" lower with the crank centerline at 11". Modern, high travel set-ups, may place the crank centerline at 13". Then travel the front end 3" to 4.5" under braking, before turn in. That puts the crank centerline at 8.5" to 10" depending upon the travel strategy.
If we put that mass at 8.5" ... the cornering speed capability compared to it being at 11" ... is a significant difference. All things being equal ... contact patch, car weight, track width, optimized spring & bar rates ... the car with the lower CG can carry significantly more speed. The other bonus is, the front end is loaded more from static load transfer of the front end being 3"-4.5" lower. This is in addition to the dynamic load transfer from braking g-forces.
Lastly, combined with the strategy of running the car flatter (less roll angle) increases the loading on the inside front tire ... increasing it's grip ... adding to the total grip the front end has. We can't go faster through a corner than the front end has grip. That needs to be our focus. Running a low roll strategy ... say 1° ... keeps the inside tires loaded more than a high roll strategy around 3°.
Make sense?
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