When people think about reducing weight in a race car, they usually focus on obvious components like wheels, panels, or engine parts. But one of the most overlooked areas for weight and packaging improvement is the wiring system.
A vehicle’s wiring loom runs throughout the entire chassis. Depending on design and materials, it can contribute a surprising amount to total vehicle mass and can also affect serviceability, airflow, and component layout. Understanding how wiring materials differ is important for anyone building or optimising a performance vehicle.
Why Wiring Weight Matters
In motorsport, small weight changes can influence performance, especially in categories where power-to-weight ratio and class limits are tightly regulated.
Reducing wiring weight can provide:
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improved acceleration potential
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lower overall vehicle mass
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better weight distribution options
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easier packaging of components
While the weight of a single wire may seem insignificant, a full vehicle harness can contain hundreds of individual conductors. Material choice therefore becomes a meaningful engineering decision.
The Role of Insulation Material
One of the biggest factors affecting wire weight and size is insulation type.
High-performance wiring systems often use ETFE-insulated wire manufactured to M22759-series specifications. Compared with common automotive insulation materials such as PVC or cross-linked polyethylene (TXL), ETFE insulation typically offers:
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thinner insulation walls
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high temperature resistance
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strong abrasion resistance
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excellent chemical resistance
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high dielectric strength
Because the insulation can be thinner while still meeting performance requirements, the overall wire diameter is smaller and lighter.
Terminology note: “Tefzel®” is a registered trademark of The Chemours Company. ETFE is the correct generic material name used when referring to this insulation type.
Smaller Diameter = Better Packaging
Compact wiring provides advantages beyond weight reduction.
Smaller-diameter conductors allow for:
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tighter routing paths
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cleaner harness layout
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easier integration with modern electronics
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improved clearance around hot or moving components
In tightly packaged race cars — especially formula, prototype, or motorcycle-engine builds — available space is extremely limited. Efficient wiring design can simplify installation and reduce interference with other systems.
Reduced Bulk Improves Serviceability
A well-designed harness isn’t just lighter — it’s also easier to work on.
Smaller, properly structured looms can make it easier to:
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access connectors
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trace circuits
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replace sensors
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diagnose faults
This becomes particularly valuable in motorsport environments where repairs may need to be performed quickly between sessions or events.
System Design Matters as Much as Materials
While insulation material plays a major role, weight and packaging efficiency are also influenced by harness design choices such as:
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correct wire gauge selection
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eliminating unnecessary circuits
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optimised branch lengths
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balanced loom layout
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connector selection
An efficiently designed loom often weighs less simply because it contains only what the vehicle actually needs.
Why This Knowledge Is Useful
Understanding how wiring materials and construction affect weight and space helps builders make informed decisions when designing or upgrading electrical systems.
Even for hobbyists or club-level racers, improved wiring design can result in:
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easier vehicle assembly
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more reliable electronics
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improved accessibility for maintenance
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cleaner overall vehicle layout
Key Takeaway
Wiring may not be the most visible part of a race car, but it plays a major role in performance, reliability, and packaging. Material selection and harness design both influence weight, durability, and ease of installation.
For anyone building or refining a performance vehicle, understanding these factors can help achieve a more efficient and reliable electrical system.