One of the best dollar for dollar upgrades for the K24 engines. 12-15whp is an average gain. The item "2012-15 Civic Si Black RBC Intake Manifold Swap Kit with ZDX Throttle Body adapter" is in sale since Wednesday, October 5, 2016. This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Air Intake & Fuel Delivery\Intake Manifold". The seller is "valexracing" and is located in Elk Grove Village, Illinois.This item can be shipped worldwide.