1 (X):  Suspension Roll Rate

N-m/deg

The change in axle moment per change in axle roll angle (excluding tires) or:

track = abs((right wheel center y) - (left wheel center y))

roll rate = track^2/(C(3,3)-C(3,9)-C(9,3)+C(9,9))/rtod/1000

2 (Y):  Total Roll Rate

N-m/deg

The change in axle moment per change in axle roll angle (tires in series) or:

track = abs((right wheel center y) - (left wheel center y))

deltaz = C(3,3)-C(3,9)-C(9,3)+C(9,9)+2/(tire stiffness)

roll rate = track^2/deltaz/rtod/1000

3 (Z):  Tramp Rate

N-m/deg

The change in axle moment per change in axle roll angle (tires in parallel) or:

track = abs((right wheel center y) - (left wheel center y))

deltaz = (C(3,3)-C(3,9))*1/(tire stiffness)/

(C(3,3)-C(3,9)+1/(tire stiffness))+

(C(9,9)-C(9,3))*1/(tire stiffness)/

(C(9,9)-C(9,3)+1/(tire stiffness))

tramp rate = track^2/deltaz/rtod/1000

4 (RX):  Roll Center Height

mm

The suspension roll center is found by intersecting the line connecting the left tire patch and the left tire patch front view instant center with the line connecting the right tire patch and the right tire patch front view instant center. The roll center height is defined as the difference between the roll center z coordinate and the average tire patch z coordinate.

ltpdz = C(3,3)-C(3,9) + 1/(tire stiffness)

rtpdz = C(9,9)-C(9,3) + 1/(tire stiffness)

Orientation A:

ltpdy = C(2,3)-C(2,9) + slr*(C(4,3)-C(4,9))

rtpdy = C(8,9)-C(8,3) + slr*(C(10,9)-C(10,3))

Orientation B:

ltpdy = -C(2,3)+C(2,9) + slr*(-C(4,3)+C(4,9))

rtpdy = -C(8,9)+C(8,3) + slr*(-C(10,9)+C(10,3))

m1 = -ltpdy/ltpdz

m2 = -rtpdy/rtpdz

rcy = (ltpz-rtpz+m2*rtpy-m1*ltpy)/(m2-m1)

rcz = ltpz+m1*(rcy-ltpy)

roll center height = rcz - (ltpz+rtpz)/2

5 (RY):  Roll Center Lateral

mm

The roll center lateral location is defined as the roll center y coordinate.  See comment for Component 4 for equations.

6 (RZ):  Not Used

Not Used

Not Used