Firewall Rubber Grommet - 51mm (2") OD 21mm (13/16") ID

Overview

Professional-grade firewall grommet that seals your wiring harness penetrations whilst protecting cables from sharp metal edges. Essential for any EFI conversion, turbo build, or standalone ECU installation where you're running new wiring through the bulkhead.

Technical Specifications

• Part Number: HT-039003
• Outside Diameter: 51mm (2")
• Inside Diameter: 21mm (13/16")
• Material: Durable rubber compound
• Application: Firewall/bulkhead wiring penetrations

Why You Need This

Every standalone ECU installation requires clean, protected wiring runs through the firewall, and bodged holes are where professional builds fall apart. Sharp metal edges will eventually chafe through your expensive engine harness, whilst unsealed penetrations let water, fumes, and road debris into the cabin. This isn't just about aesthetics — it's about reliability and safety.

Whether you're running a Haltech Elite into an LS swap, threading wideband O2 sensor cables through the bulkhead on a turbo SR20 build, or completing an RB25 conversion with full engine management, proper firewall grommets are non-negotiable. The 21mm ID suits most standard automotive wiring bundles, whilst the 51mm OD provides excellent sealing area for professional installation. We see too many builds where customers skip these basic components, only to face harness damage or water ingress months later.

ECU & System Compatibility

Universal fitment for any wiring application. Commonly used with Haltech Elite and Nexus series ECU installations, wideband controller wiring, and aftermarket engine management systems requiring firewall penetrations.

What's in the Box

• 1x Haltech Firewall Rubber Grommet (51mm OD, 21mm ID)

Complete Your Build

Most customers completing standalone ECU installations also add split-loom conduit for harness protection, weatherproof connectors for sensor extensions, and additional grommets for multiple penetrations. Our technical team can recommend the complete wiring protection package for your specific build — whether that's a simple weekend project or a full competition preparation. With our UK stock, you won't be waiting weeks for these essential finishing touches that separate professional installations from weekend bodge jobs.