Skunk2's cutting edge Composite Fuel Rail for the '06 to '11 Civic Si is here. Skunk2's Composite Fuel Rails are made using a proprietary carbon impregnated, aerospace thermo polymer composite a material that's 33% lighter, 60% stronger, and operates up to 100°F cooler when compared to aluminum and insulates fuel from both radiant and conductive heat transfer underneath the hood, resulting in increased horsepower and torque. Composite Fuel Rails also feature large 0.625 inch internal bores for superior fuel injector pulsation dampening, are machined with a smooth interior finish, and feature radius cut fuel injector outlets for improved flow characteristics. The special design that eliminates the sharp internal angles where the main bore meets the fuel injector bores inherent with conventional extruded and drilled aluminum designs can only be achieved with such composite materials. Skunk2's K-series Composite Fuel Rails are compatible with the factory fuel system, as well as all fuels, including alcohol, and can support up to 1,200 hp, with gains as high as three percent realized during testing.