Firewall Rubber Grommet - 63.5mm (2.5") OD 44.45mm (1.75") ID

Overview

Professional-grade firewall grommet designed for clean, weatherproof harness routing in performance engine swaps and standalone ECU installations. This 63.5mm outer diameter grommet provides the perfect seal for main engine harnesses passing through firewalls whilst protecting wiring from sharp metal edges and environmental contamination.

Technical Specifications

• Part Number: HT-039005
• Outer Diameter: 63.5mm (2.5")
• Inner Diameter: 44.45mm (1.75")
• Material: Automotive-grade EPDM rubber
• Temperature Range: -40°C to +120°C
• Application: Firewall penetration sealing

Why You Need This

Every serious engine swap or standalone ECU conversion requires professional harness routing through the firewall, and this is where many builds fall short. Cutting oversized holes then bodging them with foam or tape creates water ingress points, EMI interference paths, and fire hazards. The sharp edges of poorly finished holes will eventually cut through harness sheathing, leading to intermittent faults that'll drive you mad during commissioning.

This grommet's 44.45mm internal diameter is perfectly sized for bundled main harnesses in LS swaps, RB conversions, and 2JZ transplants. The thick-wall construction grips firmly in standard 63.5mm chassis holes whilst the flexible inner seal accommodates varying harness diameters. We see this specification constantly in professional motorsport builds where environmental sealing and harness protection are non-negotiable. Whether you're running a Haltech Elite controlling a turbocharged Honda K-series or managing a naturally aspirated BMW S54 conversion, proper firewall sealing protects your investment from moisture, debris, and the inevitable workshop spillages.

ECU & System Compatibility

Essential component for any standalone ECU installation requiring firewall penetration. Commonly used with Haltech Elite 550, 750, 1000, 1500, and 2500 systems, plus Nexus R3 and R5 platforms where main harnesses route from engine bay to interior-mounted ECUs. Compatible with both factory and custom harness applications.

What's in the Box

• 1x Haltech Firewall Rubber Grommet (63.5mm OD, 44.45mm ID)
• Installation guide

Complete Your Build

Most customers fitting firewall grommets are in the middle of major harness routing jobs. Contact our technical team for recommendations on complementary wiring protection, ECU mounting solutions, and harness management components. We maintain comprehensive UK stock of professional wiring accessories and can advise on the complete electrical infrastructure for your build based on years of hands-on installation experience.