Vehicle Physics

Project Tourge is a driving game built around the car itself. The engine, drivetrain, suspension, steering and tyres are connected so that the handling comes from the state of the vehicle, the driver's inputs and the road beneath it.

One car, many connected systems

Power begins at the engine, passes through the clutch and gearbox, reaches the differential and finally arrives at the driven wheels. At the same time, the suspension carries the car's weight and controls how quickly that weight moves between the four tyres.

Those systems cannot be separated while driving. Braking moves load toward the front axle. Turning asks the front tyres to produce lateral force. Applying throttle asks the driven tyres for acceleration as well. If one tyre is already busy, the driver has to work with what remains.

This is why Project Tourge does not treat grip as a fixed number attached to a car. Tyre compound, load, pressure, temperature, wear, road surface and weather all affect the result. The vehicle responds to the combination rather than selecting a ready-made handling reaction.

Physics on a consistent clock

The main vehicle simulation runs at 100 Hz. Keeping physics on a fixed update allows the chassis to behave consistently even when the rendering frame rate changes. The faster parts of the vehicle, including tyre and drivetrain behaviour, receive additional attention within that update.

The number matters less than the reason behind it. Wheel speed can change quickly, grip can be lost in a moment and a steering correction needs to arrive without waiting for a slow frame. A stable physics clock gives those events a reliable timeline.

Accuracy with a purpose

Project Tourge is not presented as laboratory software. It is a game, and every system still has to communicate clearly to the player. Our use of “accurate” means preserving important relationships: weight transfer should matter, braking and turning should compete for tyre grip, gearing should change how power reaches the road, and alignment should affect the steering.

The same approach continues outside the chassis. Wet roads change the drive as well as the image. Engine parts affect the sound as well as performance. A damaged tyre changes both its appearance and the way its corner of the car behaves.

The result we want is a car that can be learned. When it reacts, the driver should be able to understand why, adapt their technique and make a useful change in the garage.

The car is the experience. Every system exists to make driving it more believable and more rewarding.