Problem
The Independent Front Suspension (IFS) motion ratio significantly affects damper valving, leading to potentially soft valving at the wheel position, especially in vehicles like the Prado. This can result in reduced kinematic control and increased body roll, pitch, and heave. The original design of the Prado IFS prioritizes comfort over handling.
Key Concepts
- Motion Ratio (MR): The ratio between strut shaft travel and wheel travel.
- Force and Velocity Scaling: Increasing the motion ratio increases force at the wheel but decreases velocity.
- Critical Damping: The ability to quickly dampen oscillations (roll, pitch, heave). The Prado IFS has a low critical damping at the wheel position.
- Knee Velocity: The velocity at which the damping curve transitions. Shortening knee velocities (50-100mm/s at the wheel) improves kinematic response.
Solution
Optimizing the valving curve to shorten the knee velocities can improve the kinematic response of the Prado IFS. Specifically, shortening the knee at the strut position to around 50-60mm/s will result in approximately 100mm/s at the wheel position. This can be achieved by designing a new valve stack.
- A new valve stack design can produce around 500N more rebound at 100mm/s, which will help minimise squat and heave under low speed driving conditions.
This technical summary was auto-generated based on recovered archives. Do not rely on its factual accuracy. Refer to the original thread. Source: View Original Conversation
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