How to Edit JBeam Cars in BeamNG.drive

BeamNG.drive is built around a physics engine that simulates soft-body dynamics in real time — and JBeam is the file format that makes it possible. Every vehicle in the game is defined by JBeam files: structured data that tells the engine how a car's nodes, beams, and collision surfaces behave under stress. If you want to modify vehicle handling, change structural rigidity, or tweak how a car crumples, you'll need to get comfortable editing JBeam files.

What Is JBeam and Why Does It Matter?

JBeam (JSON Beam) is BeamNG's proprietary vehicle description format. It's built on JSON syntax, which means it's human-readable plain text — no compiled binaries, no special exporter required. Just a text editor and an understanding of the structure.

Every vehicle is made up of:

Nodes — points in 3D space that define the skeleton of the vehicle
Beams — connections between nodes that simulate structural material properties
Collision triangles — surfaces the physics engine uses for contact detection
Flexbodies — the visual mesh layered over the physical skeleton

When you edit JBeam, you're changing the underlying physics model — not just the appearance. That distinction matters a lot.

Setting Up Your Editing Environment

You don't need specialized software, but a few tools will make the process significantly more manageable.

Recommended tools:

Tool	Purpose
Visual Studio Code	Free code editor with JSON syntax highlighting
Notepad++	Lightweight alternative for simple edits
BeamNG's built-in Vehicle Editor	Visual node/beam inspector inside the game
WinMerge or similar diff tool	Compare original vs. modified files

JSON doesn't forgive formatting errors. A missing comma or mismatched bracket will prevent the vehicle from loading entirely. VS Code with a JSON linter extension catches these problems before you even launch the game.

Finding the Right JBeam Files 🔧

Stock vehicles are stored in BeamNG's core files, but you should never edit those directly. Instead, use the game's mod system.

For stock vehicles:

Navigate to DocumentsBeamNG.drivemods on your system
Create a new folder structure mirroring the vehicle's path in the game directory
Copy only the specific JBeam file you want to modify into your mod folder
BeamNG loads mod files with priority over base files — your copy overrides the original without touching it

For mod vehicles: Mod vehicles are typically installed as .zip files in the mods folder. Unzip the mod, locate the vehicles subfolder, and find the .jbeam files inside.

Always keep a backup of any file before editing it.

Core JBeam Concepts You Need to Understand

Nodes