Center of Gravity Height
CENTER OF GRAVITY HEIGHT
Finding the center of gravity height can be done in several
ways, none of which are accomplished very easily and without some work.
Presented here is the easiest method. The center of gravity height is calculated
by weighing the car when level and then raising the car at least 10 inches at the
rear and weighing the front again. Enter the data into
the program below to calculate your center of gravity height.
Before you begin:
Be sure that all fluids are full
Replace each shock absorber with a solid link to eliminate
Make sure the tires are inflated to the maximum pressure as
specified by the manufacturer to eliminate any sidewall flex
Note: If these steps are not taken, the
calculations will be inaccurate
Center of Gravity Height Formula
This program is used to calculate center of gravity height. Enter the data in the boxes below, then click the "Calculate"
Total Weight (lbs)
Front Wheel Weight - Level (lbs )
Front Wheel Weight - Raised (lbs )
Raised Height (inches)
Left Front Tire Size
(circumference in inches)
Right Front Tire Size (circumference in inches)
Center of Gravity Height from Ground
How does all this work?
Tan q = opposite /
Therefore using the Pythagorean Theorem:
This calculates the Center of Gravity Height from the axle height.
To find the CGH from the ground, you must add your axle height to the
above calculation. You can measure your axle height or calculate it
using the average of your two front tire sizes and the formula for the
circumference of a circle.
For example: Your LF is 85.5" and your RF is 87". Your
average circumference is (85.5 + 87) / 2 = 86.25". Your axle height
is (86.25 / 2) / 3.1416 = 13.727". Add this number to the CGH
to find the center of gravity height in relation to the ground.
Frequently Asked Questions
The true center of gravity is actually a 3 dimensional
point in space. You need to know the CG along the wheelbase, the CG for
the track width of the car, and the CGH. Where these 3 coordinates
intersect in space is the actual center of gravity. The following formulas will
calculate the Wheelbase CG (CGwb) and the Track Width CG (CGtrw).