Through its technical partnership with the championship-winning Compass360 Racing team, engineers at Skunk2 have developed an all new cold air intake system for the 12-15 Honda Civic Si. The results are the best performing, best fitting intake system netting +6whp and +8lbs-ft of torque. Skunk2's Cold-Air Intake is manufactured from molded polymer plastic for superior intake air insulation when compared to aluminum as well as for a smooth, continuous taper. When compared to aluminum, the thicker polymer material results in a superior thermal barrier and lower intake air temperatures. Each kit includes a 3.5- in. internal diameter lower tube and a tapered, 3.5- in. to 3.0- in. internal diameter upper tube that connects to the factory throttle body with a high-quality, silicone connector (larger diameter connectors for use with Skunk2 throttle bodies or similar sold separately). In an effort to reduce the possibility of submerging the air filter during wet conditions, Skunk2's design positions the air filter downward-facing for approximately two inches of additional ground clearance when compared to competitors' designs that locate the air filter from the side. That, combined with a design that doesn't require cutting or modifying the factory fender liners, greatly reduces the chances of water entering the intake during wet conditions. Unlike other intake systems, only Skunk2's unique design and brackets allow for the OEM battery to be retained.