The science
Aero. Downforce Fz = ½ ρ CL A v² and drag Fd = ½ ρ CD A v² (ρ = 1.2 kg/m³, A = 1.1 m²). Wing angle sets CL linearly; CD = CD0 + k CL² models induced drag. These coefficients are tidy textbook-style numbers, not CFD of a real car; ground effect, yaw and ride-height sensitivity are ignored.
Tyres. Friction coefficient falls with load: μ(N) = μ0 (1 − s (N/N0 − 1)) (load sensitivity). The whole car is one lumped contact patch, so weight transfer and axle balance are not modelled. Temperature and wear are ignored.
Corners. With N = mg + Fz and a cornering requirement m v²κ = μN the speed limit is solved numerically; for constant μ it is v = √(μ g / (κ − μ ρ CL A /2m)) - note that if the denominator is ≤ 0 downforce alone holds the car at any speed.
Straights. Power-limited acceleration F = min(P/v, grip), brake-limited deceleration, combined by the friction circle (Fx/μN)² + (Fy/μN)² ≤ 1. The lap is a quasi-steady-state solution: forward and backward passes over a 2 m track spline, lap time = Σ ds / v.
Honest limits. A point mass on a flat track: no suspension, no gears, no slip angles, no slipstream, no elevation. The drivable lap uses the same equations but with simple steering. Car, circuit and trees are invented and generic. Meshes and baked light came from Unity (no Blender); the runtime is Three.js.