Adams Assignments – Problem 4 – Steering geometry 2

BEFORE HARDPOINT MODIFICATION

after hardpoint modification

run a simulation

original caster angle was 5.369deg

modified caster angle is 4.1248deg

effect: reducing the caster angle value will reduce steer effort but reduce caster trail that will lower the self-aligning torque and straight- line stability.

original caster moment arm was 8.58mm

modified caster moment arm is 21mm approx

effect: the increase in caster moment arm will effect the feedback of the driver.

original kpi angle is 10.08deg

modified kpi angle is 13.06deg

effect: increasing the kpi angle will increase the raising effect of the car.

original steering offset was 85.77mm

modified steering offser is 84.9mm

effect: decreasing the steering offset will reduce the torque steer effects

original longitudinal steering offset was - 18.74mm

modified longitudinal offset is 0mm

effect: reducing this will increase trail length and will thus increase straight line stability

original scrub radius was 33.8mm

modified scrub radius is 19.87mm

effect: it will increase braking stability and will help decrease tyre wear.

The above done modification is done by modifying control arm outer ball joint.side view x-axis modification will change caster,caster moment arm and steering longitudinal offset.Changing any one of the parameters will affect the other two. In y-axis the scrub radius, steering offset and kpi parameters will be affected. If we change the offset, kpi may be the same but scrub radius might change. Thus all the values are dependent on each other and cannot be modified independently.