Experimental Grip Dynamics Mod 0.4.0f

This mod fundamentally reworks BeamNG's tyre friction by replacing the native binary grip with a own adaptation of Pacejka-based method. This mod calculates real-time longitudinal and lateral forces based on real-time slip ratio, slip angle and camber angle, delivering progressive, predictable tyre behavior at the limit. Although it cannot uphold BeamNG's purity on real-time physics, all values are dynamically calculated based on vehicle status, and not looking up for preset values.

Longitudinal Force (Braking / Acceleration):

• Progressive buildup to peak
• gentle falloff beyond optimal slip
• load-dependent peak force

Lateral Force (Cornering):

• Progressive initial response to stiffness
• Clear peak at certain slip angles
• predictable fade post peak

Camber Effects:

• Rational grip loss with increased camber angle
• Dynamic per-wheel calculation based on suspension geometry

Current status & Limitations:
Experimental stage:

• Single vehicle tested: ETK K-series GT-IV
• Tire size only: 18x11 sport and race tyres (front and rear)

Activation:

1. Select ETK K-series GT-IV (or other supported vehicle with 18x11 tyres)
2. Equip 18x11 race tyres (front and rear must be equipped)
3. The mod auto-activates when the vehicle spawns

Core problems (try to) addressed:
1. Binary grip on static / sliding friction transition, which makes limit handling unpredictable.

• minimal progressive feedback due to abrupt traction loss
• difficult sliding control due to the "stribeck"-controlled transition

2. Peak lateral force remains constant across load, real tyres exhibit load sensitivity.
3. Vague FFB

Technical Implementation:
The mod bypasses BeamNG's native `noLoadCoef`, `fullLoadCoef`, and `loadSensitivitySlope` parameters. Instead, it calculates grip through Pacejka Formula. The real-time slip ratio, slip angle and camber angle is evaluated. The longitudinal and lateral forces on each wheel are then constrained by a friction ellipse model that respects the grip budget that each tyre has. Then, the constrained forces are synthesis to a isotropic friction which could be assigned to tread nodes on BeamNG's pressure wheel model.

About current tyres:
Despite not having the real tyres data, the relative performance can still be introduce into the game:


Next Step:

• Expand tyre size supported
• Add vehicle compatibility
• Thermal and Wear integration

Some thoughts:
I started this mod a few weeks ago after the semester break begins, and I just noticed there is a new Tire Physic Mod few days ago(I missed as I just back to BeamNG for some weeks)... I understand the philosophy of BeamNG is to create a physical, real-time tyre model that obeys Newton's laws instead of empirical relations. However, as I enjoy sim racing with my friends, we thought BeamNG could be extremely realistic... in the future. For now, we need a workable handling improvement mod.