CST4 Turbocharger

The CorkSport CST4 Turbocharger Upgrade is engineered as a direct-fit replacement for the stock K04 on 2006-2013 DISI MZR engines found in the Mazdaspeed 3, Mazdaspeed 6, and CX-7. This turbo upgrade is designed to support power levels ranging from 250-450 wheel horsepower, making it suitable for mildly modified vehicles with full bolt-ons and auxiliary fueling, as well as budget-built engines. It features a MHI Journal Bearing CHRA, an OEM-fit compressor cover, and a custom MHI 18G billet compressor wheel capable of supporting a 50 lbs/min flow rate and up to 30psi of boost. The high-flow MHI TD05H turbine wheel utilizes a 9-blade design to reduce rotating mass for improved response and spool. The CST4 offers a choice between two turbine housing options: a 0.66 A/R internal wastegate (IWG) setup for straightforward installation, or a 0.82 A/R external wastegate (EWG) setup designed for 44mm EWGs (sold separately) and including an elbow pipe and V-band clamp. A free CorkSport 3.5 bar MAP sensor is included for accurate boost pressure readings up to 37psi. Installation is estimated to take 5 hours and includes all necessary hardware such as gaskets and studs. However, an upgraded High-Pressure Fuel Pump (HPFP) and a COBB Accessport with a custom tune are required for operation. Auxiliary fueling is also necessary for peak power. Note that some aftermarket downpipes may not clear the EWG elbow included with the EWG variant. The CST4 comes with a 1-year limited warranty.