Step 11: Adjust Springs Natural Frequency Hz
Natural Frequency Hz
“The effective spring rate value changes depending on the suspension type
and lever ratio. The natural frequency is a representation of how the ride
feels as a result of this. The higher the value, the stiffer the feeling of the
ride. The lower the value, the more gentle the ride feels. Matching the natural
frequency of the front and back wheels makes for a smoother ride.”
Spring rate is a crucial setting and very hard to manage. Generally
speaking, lower frequencies produce a softer suspension with more
mechanical grip, however the response will be slower in transient. Higher
frequencies create less suspension travel, allowing lower ride heights,
lowering the center of gravity, and faster response.
Standard spring rates frequencies:
0.5 – 1.5 Hz for passenger cars
1.5 – 2.0 Hz for sedan racecars and moderate downforce cars
3.0 – 5.0 Hz for high downforce racecars
Last part of Polyphony explanation is in red because is not correct. For a
smooth ride rear frequency must be about 10% higher than front frequency.
That’s because there is a time delay between front and rear hitting a given
road bump. For this reason rear frequency must be higher to “catch up” with
front, in order to minimize pitching of the body due to road bumps.
On racecars higher damping ratios will reduce oscillation and compensate
downforce, allowing lower ride height.
General rule: Fast, long turns -> Lower Hz
Quick transitions, need for agility -> Higher Hz