Add horsepower and sound to your Civic Si with the new Mishimoto Civic Si Performance Air Intake. This kit is engineered specifically for your 2006 -- 2011 Honda Civic Si and includes everything needed to replace the restrictive stock airbox. This dyno-proven air intake provides 8 hp and 6 tq gains over the stock intake while maintaining safe air/fuel ratios. Installation is quick and simple, perfect for some extra punch on the street or autocross course. The Mishimoto Honda Civic Si Performance Air Intake includes everything needed for installation, installs in under one hour, and works perfectly with the stock tune. The mandrel-bent aluminum intake pipe is available with a polished or black powder-coated finish. This pipe utilizes a CNC-machined mass airflow sensor (MAF) housing to provide accurate and consistent MAF readings, which translates into a smooth power band. To reduce air intake temperatures, a powder-coated heat shield is placed between the air filter and hot exhaust manifold, significantly reducing heat-soak. The Mishimoto free-flowing air filter provides an 85-percent greater surface area, optimal airflow, and proper filtration of dirt and debris. The included Mishimoto oiled air filter is completely serviceable, allowing for a lifetime of reliable use. Additionally this kit includes a silicone coupler, clamps, and all other hardware necessary to complete a quick installation for easy bolt-on power. Along with an upgrade in power, this intake also provides an aggressive and rich intake tone that is a huge improvement over the stock intake, especially when VTEC activates. The Mishimoto Honda Civic Si Performance Air Intake is designed in Delaware, USA and includes the Mishimoto Lifetime Warranty