Mazdaspeed 3/6 CST4 Turbocharger Replacement CHRA

High Performance CHRA:

MHI Journal bearing CHRA housings are used for both the CST4 and CST5 turbochargers for their increased cooling capacity and proven reliability.

High-performance journal bearings and a 360-degree high-performance thrust bearing is used. Comparing the compressor and turbine wheels, we have a wheel size ratio of 1:21.

Proven By Thousands Of Community Members!

The CST4 Mazdaspeed K04 Upgrade is a perfect fit for the mildly modified Mazdaspeed 3 and Speed 6 using stock fueling up to budget-built engines with FBO and auxiliary fueling. Replace your KO4 Turbo with the easiest and most complete performance turbo for the Mazdaspeed and have room to grow to 450whp capabilities with the CST4.

*Does your buddy have an old CST4 lying around - refresh it and skip rebuilding your smaller KO4 Turbo!

Read The BlogThe CorkSport CST4 – The Best Turbo for the Mazdaspeed

Billet Compressor:

Utilizing a custom MHI 18G billet compressor wheel, the CST4 can efficiently support 50 lbs/min flow rate and boost pressures to 30psi.

Compared to cast counterparts, modern forge-milled wheels provide higher boost thresholds, improved response, and increased efficiency to get more power from a small package.

High Flow Turbine:

Paired with the compressor wheel is an MHI TD05H high-flow turbine wheel. This wheel uses a 9-blade design which reduces overall rotating mass and thus improves response and spool.