Stopping Distance = (original velocity^2)/(2 * deceleration rate)
velocity in MPH times 1.4666 gives velocity in ft/sec
deceleration rate of 1 G = 32.2 ft/sec^2
example for 0.8, 1.0 and 1.2 G
distance from 60 MPH = (1.4666*60)^2/(2*32.2*.8) = 150ft
distance from 60 MPH = (1.4666*60)^2/(2*32.2*1) = 120ft
distance from 60 MPH = (1.4666*60)^2/(2*32.2*1.2) = 100ft
Formula courtesy of Stoptech:
http://www.stoptech.com/technical/Th...%20Systems.pdf