Skunk2 Alpha Series Header for 12-15 Civic Si/13-15 ILX

Skunk2 Alpha Series Header for 12-15 Civic Si/13-15 ILX

Transform the way your K-series breathes with the Skunk2 Alpha Series Header for 12-15 Civic Si/13-15 ILX. Born from the same R-type engineering that powers record-setting Skunk2 race cars, this one-piece stainless masterpiece unlocks noticeable horsepower, sharper throttle response, and that unmistakable VTEC growl—without sacrificing OEM fit or daily-driver reliability.

Why it hits harder than stock

• Race-bred 4" cast bellmouth merges exhaust pulses into a turbulence-free 3" outlet, freeing up exhaust flow the factory manifold strangles.
• CNC-mandrel-bent T-304 stainless primaries shrug off heat, corrosion, and road salt for years of spirited pulls.
• Beefy ½" laser-cut flanges stay flat and sealed under repeated heat cycles—no more pesky gasket leaks.
• Integrated flex section absorbs engine movement, protecting welds and downstream piping.
• Dual O2 bungs in factory locations (plus an included defouler) keep the ECU happy and MIL lights off.*
• Direct bolt-on to the OEM cat-back; no cutting, no hacking, just pure performance.

Track-minded construction

• One-piece, cat-delete design eliminates an exhaust restriction worth double-digit wheel horsepower on naturally aspirated K24Z engines.
• CAD-modeled runner lengths and merge collector geometry equalize exhaust pulse timing for a broader, smoother powerband—ideal for both autocross launches and highway pulls.
• Engineered and dyno-validated in California by Skunk2 Racing, a brand trusted by championship-winning Honda teams worldwide.

Fitment

• 2012-2015 Honda Civic Si (FG/FB)
• 2013-2015 Acura ILX 2.4L (DE)
• (Also bolts up to later 2016-2017 ILX 2.4L chassis using the same K24 powertrain.)

Installation Snapshot:

Intermediate skill • 1–2 hrs • New gasket, O2 defouler & mounting hardware included • No cutting/tune required (ECU retune recommended for max gains).