Stage 4 Titanium Hardware Engine Bay Kit - Honda Civic Si (2016-2021)

Fast Turn Fittings Stage 4 Titanium Hardware Engine Bay Kit - Honda Civic Si (2016-2021)

Upgrade your 2016-2021 Honda Civic Si engine bay with the Fast Turn Fittings Stage 4 Titanium Hardware Kit. This is the most in-depth engine bay kit available for the platform, replacing the visible factory hardware—and the flimsy plastic clips—with high-strength GR5 titanium for a clean, corrosion-resistant finish.

Key Features

• GR5 Titanium Construction: Extremely durable, anticorrosive, and lightweight for a long-lasting finish.
• Replaces Plastic Clips: Swaps the factory plastic clips for premium titanium hardware.
• Complete Hardware Set: Includes 42 titanium bolts, 44 titanium washers, 8 titanium nuts, and 15 well nuts.
• Multiple Color Options: Available in a range of hardware finishes to match your build.
• Easy Installation: Comes with clear instructions that walk you through where to place each hardware piece.

Specifications

• Material: GR5 Titanium
• Hardware Included: 42 Bolts, 44 Washers, 8 Nuts, 15 Well Nuts
• Coverage: Radiator Shroud/Cover, Headlights, Core Support, Fenders, Radiator Stay, Battery Tie-Down, Battery Heat Shield, Hood Hinges, Strut Towers, Fuse Box, ECU Bracket, A/C Line Bracket, Coolant Reservoir, Coolant Overflow Hose Bracket, Fuel Line Bracket Cover

Fitment / Applications

• 2016-2021 Honda Civic Si

Notes

• Developed using a 2018 Honda Civic Si.

Pro Tip: Use the included location diagram to confirm each fastener placement before final torque for a fast, effortless setup.

Read our full guide: Honda Civic Performance Parts: The Ultimate Build Guide from EG to Type R

Read our full guide: Best Titanium Engine Bay Kit: The Complete Buyer's Guide 2026