Motorsport Upgrade

Tefzel Wiring

+$300 Add-On

Upgrade your SVK harness to Tefzel (ETFE) wire — the conductor insulation of choice in aerospace, Formula 1, and professional motorsport applications. Tefzel wire offers a thinner, lighter insulation than standard TXL with a significantly higher temperature and chemical resistance rating, making it ideal for the most demanding engine builds.

  • Genuine Tefzel (ETFE) insulated wire — MIL-W-22759 spec
  • Rated to 150°C continuous — exceeds standard TXL wire by a significant margin
  • Thinner insulation wall — smaller bundle diameter and reduced weight
  • Exceptional resistance to fuels, oils, solvents, and automotive chemicals
  • Abrasion resistant — harder surface than TXL for longer harness life
  • Preferred wire in aerospace, defense, and professional motorsport
  • 1-year warranty on workmanship

What's Included

The Tefzel wiring upgrade replaces all standard TXL conductors in your SVK harness with Tefzel (ETFE) insulated wire throughout. Every circuit in the harness — engine, chassis, sensors, and accessories — is built using Tefzel wire. This is specified during the build process, not a modification after the fact.

1-Year Warranty: Backed by a 1-year warranty covering defects in materials and workmanship. See our FAQ for full warranty details.

Available as Harness Add-On Select During Build
Details

Why Tefzel?

Tefzel is the brand name for ETFE (ethylene tetrafluoroethylene) insulated wire manufactured by DuPont. It is specified under MIL-W-22759 for aerospace and military applications. The ETFE insulation provides a unique combination of high temperature rating, chemical resistance, thin wall construction, and abrasion resistance that no other common automotive wire insulation can match.
TXL (cross-linked polyethylene) wire is rated to 125°C and is SVK's standard wire — already a step above typical automotive wiring. Tefzel wire is rated to 150°C, has a thinner insulation wall (resulting in a smaller, lighter harness), and substantially better chemical and abrasion resistance. For race and high-output builds, Tefzel is the next level up.
Yes. Tefzel conductors paired with Raychem DR-25 sleeving is the ultimate combination — Tefzel wire inside, DR-25 protection outside. This is how professional race teams and aerospace harness builders spec their most demanding builds. Both options can be selected together in the calculator.
Select "Yes" under the Tefzel Wiring option in the Motorsport Upgrades section of the harness build calculator on your vehicle's page. Tefzel wire is sourced and used throughout the entire harness build — this option must be selected before your order is confirmed.
The Tefzel wiring upgrade is available for all SVK harness platforms: MK4 Supra (JZA80), MK3 Supra (MA70), Lexus SC300/SC400/Soarer (Z30), and universal harnesses.