SPDZ1 K-Series Performance Header Downpipe for 2012–2015 Honda Civic Si & 2013–2015 Acura ILX K24

Unleash the full power of your K-Series engine with the SPDZ1 Performance Header Downpipe — the ultimate bolt-on upgrade for your 9th Gen Civic Si or Acura ILX K24. Designed for enthusiasts who demand more than just an OEM replacement, this downpipe is engineered to increase horsepower, improve throttle response, and deliver a raw, aggressive exhaust note — all while maintaining perfect fitment and durability.

Key Benefits:

• Big Gains, No Compromises: Unlock real horsepower and torque increases by eliminating factory restrictions and optimizing exhaust flow.
• Precision-Built Performance: Crafted from premium 304 stainless steel with mandrel-bent tubing and CNC-machined flanges for maximum durability and a perfect, leak-free seal.
• OEM-Style Fitment, Race-Proven Function: Features a cast 4” bellmouth collector with 3” outlet, designed to bolt directly to your factory or aftermarket cat-back system — no modifications required.
• Daily Driven, Track Ready: Whether you’re carving corners on the weekend or commuting daily, the integrated flex pipe absorbs vibration and movement, preventing stress on your exhaust system.
• Sensor-Ready Out of the Box: Comes with both O2 sensor and wideband sensor bungs pre-installed for easy tuning and monitoring.
• Megaphone Header Design: Enhances exhaust scavenging and improves mid-to-high RPM power for a more exhilarating driving experience.

What’s Included:

• 1x SPDZ1 K-Series Header Downpipe
• 3-Bolt Exhaust Gasket & Hardware Kit
• Pre-installed O2 & Wideband Sensor Ports
• Integrated Flex Section for Longevity 

Vehicle Compatibility:

• 2012–2015 Honda Civic Si (FG4)
• 2013–2015 Acura ILX K24

Why Choose SPDZ1?

SPDZ1 is committed to pushing the boundaries of performance. Our products are developed in partnership with top-level tuners and tested under real-world and track conditions. Every SPDZ1 part is backed by our passion for motorsport, quality, and customer satisfaction.

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