Challenge 7
- Negative caster is undesirable since there is no self-restoring/ self-aligning moment formed. The moment which occurs aids the turn rather than fight it, which results in an unstable steering.
- Too high a positive caster angle will increase the steering effort thereby causing undesirable driver fatigue. Also, a very large caster trail could mask the tire feedback which is not safe.
- Torque steer arises as an effect of Kingpin Lateral Offset. Higher the lateral offset, longer is the moment arm which causes a higher moment. The uneven drive forces at the wheels are magnified in amplitude and form a moment due to the lateral offsets.
- In reverse Ackermann setup, outside wheel steers more than the inner wheel.
- % Ackermann = Wheelbase/x(distance of turn circle centre from front axle) *100% Here, %Ackermann = (2700/4000)*100 = 67.5%
- In Revoknuckle™ geometry, the steering axis and the strut axis are different. Here, a smaller spindle is incorporated (since KP lateral offset is reduced) hence the moment created due to torque imbalance is reduced considerably.
- The two tie rod errors are - Length error - Angle error If tierod is smaller than required, there will be toe out in jounce and rebound. Whereas if tierod is larger than required, there will be toe in in jounce and rebound. When tierod is not angled correctly, there can be toe in/toe out on jounce and the converse in rebound depending on how the tierod is angled. A linear slope can be observed.