Stiffness of the suspension spring — higher = stiffer ride, less travel under load. For a 1500kg car target ~400–600 N/cm per wheel. Sports cars trend higher; rally cars lower.

What does SpringDamping do?

Energy lost per oscillation. Too low → bouncy. Too high → harsh. Aim for critical damping ratio ~0.6–0.8 of sqrt(SpringRate * Mass).

Mass center for stability?

Set CoM height to ~30–50cm above ground. Higher = tippy. Adjust via CenterOfMassOffset in the vehicle component. Front-heavy / mid-engine layouts shift X.

Fix: Unreal Chaos Vehicle Suspension Too Stiff

Quick answer: Per wheel: lower SpringRate to soften. Raise SpringDamping proportionally to control oscillation. Adjust CenterOfMassOffset for stability.

A racing prototype using Chaos Vehicles drives like a brick over speed bumps. Wheels barely move; chassis transmits every shock. Suspension is too stiff.

Suspension Parameters

On each wheel asset:

SpringRate (N/cm): stiffness. Start 400 for a sedan; 600 for sports; 250 for offroad.
SpringDamping: should scale with rate. Try SpringRate × 0.05 as a starting damping.
SuspensionMaxRaise / SuspensionMaxDrop: travel limits. Increase Max Drop for soft offroad feel.

Center of Mass

On the vehicle component:

VehicleComponent->CenterOfMassOverride = FVector(0.f, 0.f, -30.f);   // 30cm below default

Lower CoM = less roll, more stable. Sports car ~25–30cm above ground; truck ~50cm.

Tire Friction Curve

Tire asset → Friction Curve. Set lateral and longitudinal grip vs slip. Default linear is harsh; real tires roll off as slip grows. Edit curve for a smooth transition.

Anti-Roll Bars

VehicleComponent → Anti Roll Bars array. Add front and rear. Stiffness ~20 for street; higher for performance. Reduces body roll in corners.

Debug Visualizer

p.Vehicle.ShowSuspension 1
p.Vehicle.ShowWheelForces 1

Console commands. Draws suspension extension/compression and force vectors in real time. Visualize tuning.

Verifying

Drive over varied terrain. Suspension absorbs bumps visibly. No wheel lift-off on minor undulations. No bouncy oscillation. Cornering body roll within target.

“Vehicle tuning is iterative. Change one parameter, drive, observe, repeat. Start with spring rate, end with curves.”

Record reference videos of the desired ride feel (rally, sim, arcade). Tune to match the video, not abstract numbers.