SPDZ1 K Series Header Downpipe 12-15 Civic Si & 13-15 Acura ILX Stainless Bellmouth

SPDZ1 K Series Header Downpipe – 2012–2015 Honda Civic Si / 2013–2015 Acura ILX K24 (9th Gen)

Unleash the full potential of your K24 with the SPDZ1 K Series Header Downpipe, engineered for maximum flow, durability, and performance. Designed for 9th Gen Civic Si and Acura ILX models, this header downpipe eliminates factory restrictions to deliver serious horsepower and torque gains, faster turbo response, and a more aggressive exhaust note.

Crafted from 304 stainless steel with mandrel-bent tubing and CNC-machined flanges, the SPDZ1 downpipe guarantees strength, precision, and long-lasting reliability. The OEM-style 4” cast bellmouth with a 3” outlet ensures optimal exhaust velocity, while the integrated flex pipe reduces stress under high-performance driving.

Installation is a breeze with its direct bolt-on design, fitting seamlessly to the factory cat-back exhaust or aftermarket systems—no modifications required. Equipped with O2 and wideband sensor ports, plus a 90° O2 spacer and included gaskets/hardware, this kit is ready for hassle-free installation.

Key Features:

✅ Fitment:

• 2012–2015 Honda Civic Si (2-door & 4-door, 9th Gen)

• 2013–2015 Acura ILX K24 (9th Gen)

✅ Performance: Increased horsepower, torque, and improved throttle response
✅ Construction: 304 stainless steel, TIG welded, mandrel-bent tubing
✅ Design: 4” cast bellmouth with 3” outlet for maximum exhaust flow
✅ Compatibility: Direct bolt-on to OEM or aftermarket cat-back exhaust
✅ Precision: CNC-machined manifold flanges for a perfect seal
✅ Flex Pipe: Reduces stress and vibration for longer system life
✅ Complete Kit: Includes gasket, hardware, O2 plugs, and 90° O2 spacer
✅ Warranty: Backed by a 1-year manufacturer warranty

Built to the SPDZ1 Racing Standard, this header downpipe is the ultimate upgrade for Civic Si and ILX owners looking for affordable performance, superior fitment, and race-ready reliability.

The next delivery for this item is scheduled Early November 2026 We are currently taking pre-orders