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Vancouver, WA


M-TH 9A-5P | F 9A-12P | SA-SU CLOSED

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CST5 Turbo Upgrade - 2006-2013 DISI MZR Mazdaspeed

Price: $1,349.99
Price in points: What are Points?1350 points
CST5 Turbo K04 Replaement upgarde is the turbo for your Mazdaspeed 3 and Mazdaspeed 6

Products in package

Stock flange fitment, boost by 3600rpm and power to 7500...the CST5 is the turbo for your Speed

The CorkSport Turbo Upgrade is just the right fit for your Mazdaspeed! Capable of built block power and extremely fast spool times, this turbo can make 500+whp and hit 20psi by 3500-3600rpm. The CorkSport CST5 turbo can be tuned for a more laid-back curve that is stock block safe or pushed to 30+psi for built blocks and auxiliary fueling. No matter what build you have this turbo will be sure to impress.

The CST5 Mazdspeed Turbo features a MHI Journal Bearing CHRA, 0.82 Turbine A/R and 4” Anti-Surge Compressor Cover

The CST5 turbo will be available in two boost control setups: Internally Wastegated (IWG) & 44mm Externally Wastegated (EWG) w/included EWG elbow pipe & V-band clamp.

Includes a FREE CorkSport 3.5 bar MAP sensor for accurate boost pressure up to 37psi.

Read The BlogCST5 Spools!! Testing and Validation

A better turbo than the BNR S5 turbo k04
CST5 IWG and EWG Mazdaspeed Performance BNR, S3, S4, S5 precision Turbo K04

Balanced Performance

The CorkSport CST5 Mazdspeed Turbo is designed with the ideal balance in response and power for the daily-driven Mazdaspeed. Just between the CST4 and CST6, the CST5 can reach ~20psi by 3500-3600rpm and carry power to 7300-7500rpm.


BNR, S3, S4, S5 precision Turbo K04 Mazdaspeed Turbo

Stock Flange Fitment

Ease of installation and use is key to all CorkSport Performance Turbochargers. The CST5 retains the factory-style turbine flanges for a painless installation.

The turbine housing is designed with a 0.82 A/R to balance response and top-end power.


4 inch Mazdaspeed3 big turbo cover BNR, S3, S4, S5 Turbo K04 Mazdaspeed Turbo precision

Anti-Surge Compressor

4” anti-surge ported compressor housing is utilized for peak performance operation. The anti-surge porting increase the compressor map width paired with an industry standard 4” inlet to maximize the use of 3.5” and 4” intake systems.


Mazdaspeed 6 Big Turbo Upgrade Precision BNR, S3, S4, S5 Turbo K04 Mazdaspeed Turbo

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 1:15


Mazdaspeed 3 big turbo Billet Compressor wheel BNR, S3, S4, S5 K04

Billet Compressor

Utilizing the Gen1 GTX71 billet compressor wheel, the CST5 can efficiently support 56 lbs/min flowrate and boost pressures over 30psi.

Speed3 External Wastegate big turbo BNR, S3, S4, S5 Turbo K04

High Flow Turbine

Paired with the compressor wheel is an MHI TF06 high-flow turbine wheel. This wheel uses a 9-blade design which reduces overall rotating mass and thus improves response and spool.

Mazdaspeed 3 Turbo Wastegate Spring Set BNR, S3, S4, S5 Turbo K04

Tunable Wastegate Actuator

The Internal Wastegate Actuator uses a larger diaphragm and piston for improved boost control for the larger CST5.

Also included is an assortment of springs so you can specifically setup your CST5 for your Mazdaspeed.

Mazdaspeed Big Turbo Hardware Kit

All Hardware Included

The CST5 comes will all the necessary hardware for installation saves you time and money on gaskets, studs, and the specialty parts.


Mazdaspeed 3 big turbo bolt in EWG Kit BNR, S3, S4, S5 K04  precision Turbo

Choose Your Boost Control

Do you want an easy-to-use Internal Wastegate setup or an External Wastegate setup and screamer pipe? You decide with the CST5!
Internal Wastegate setup includes the 0.82 A/R IWG turbine housing and tunable IWG Actuator.
External Wastegate setup includes the 0.82 A/R EWG turbine housing and V-Band Clamp & Elbow designed for 44mm EWGs. (EWG and Screamer Pipe Not Included) Don’t worry, if you want to change your setup later you can!


Additional Mazdaspeed Features
  • Compatible with: 2006-2013 DISI MZR found in the Mazdaspeed 3, Mazdaspeed 6, & CX-7
  • Designed in America: Designed in Vancouver, Washington, in the Pacific Northwest.
  • CorkSport Service & Support: 1-year limited warranty, full-color installation instructions, all necessary components, and knowledgeable telephone support at (360) 260-2675.

  • Auxiliary fueling required for peak power operation of this turbocharger.
  • EWG variant designed for 44mm or equivalent external wastegates.
  • External wastegate is NOT included with turbo.
  • EWG dumptube/screamer pipe is NOT included with turbo.
  • Some aftermarket and all OEM downpipes will NOT clear the EWG elbow that is included with the CorkSport EWG Turbocharger. Check the "Fitment Notes" tab for details.

How To Install Your CorkSport CST5 Turbo Upgrade

It will take you five hours to install the CorkSport CST5 Turbo Upgrade with our easy-to-use instructions.

CST5 installation instructions

5 Hour Install Time

5 Hour Install Time

Difficulty: 4/5

4/5 Difficulty

1-Year Warranty

1-Year Warranty



Upgraded from the CST4 to the CST5, and I couldn't be happier! the CST4 is a great turbo, however I wanted MORE!!! the CST5 is the perfect mid-range turbo, it pulls hard, sounds great, and looks great! on a stock block and stock fueling with the CST5 my speed is making 413whp, this turbo is awesome.
After going through a couple turbo setups, I can say without a doubt, this thing hits above its’ weight class. And why should I be surprised. The car with the CST4 had incredible tip-in response, used every bit of fuel that is safely allowed on stock injectors, and punched all the way to redline. Now enter the ring, a new challenger! Built Block, 8th port, Ethanol, and a surgetank circuit track oriented solution.

Initial thoughts; It’s compact and still fits in factory location even with an IWG. Beautiful anti surge housing. All factory install.

Tuning; It was a breeze, the hot side housing I went with had EWG. Started out with a 17lb spring on pump gas, and during ethanol tuning, quickly needed to dump in 22lb spring sets. The torque curve greatly appreciated it and rewarded me with 400/400 HP/TQ on 92 octane and 525/525 on E50.

Driving; Being a bigger wheel I instantly knew that it would spool behind the CST4 but to my surprise was only a couple hundred RPM after and lights off at 3300 RPM @ 20 PSI with a ported head and flow mods. I am completely satisfied with how hard this thing hits, with very little sacrifice. A very good choice for all types of horsepower sub 525 and AUX fuel builds
Write a review

Will this turbo work with a 2.75" CAI?

Asked by Matthew | 10/02/2023, 04:07 PM | 1 answer(s)

what is the turbo outlet size for the hot side ?

Asked by Isaiah  | 11/23/2022, 10:11 AM | 1 answer(s)

Will the CST5 turbo and 3.5 inch intake piping fit without installing an EGR delete?

Asked by Ed Viviers | 05/22/2022, 04:44 PM | 1 answer(s)

This may be a dumb question, but how do you connect the intake, do you offer a special hose? Do you have any pics of it fully installed?

Asked by Sean patton | 04/01/2021, 09:56 AM | 1 answer(s)

how does this turbo pair with your large core fmic? would the small core be recommended?

Asked by Jonas | 03/15/2021, 07:23 PM | 1 answer(s)

I am looking to make 550ish AWHP with 8th port, would this turbo do it?

Asked by Joshua Scutt | 01/18/2021, 03:54 PM | 1 answer(s)

Does the cst5 require an aftermarket exhaust manifold or can the oem be used?

Asked by Andrew Dickhoff | 01/18/2021, 09:11 AM | 1 answer(s)

Do you recommend oil restrictor bolt for oil line?

Asked by Dennard d Taylor | 12/27/2020, 08:49 AM | 1 answer(s)

I currently have the stage 2 Short ram intake. Will I still be able to use it or will I need a different air intake system?

Asked by Cristian penafiel | 12/09/2020, 08:36 PM | 1 answer(s)

Can you run turbo with fbo and stock block safely?

Asked by Brandon  | 11/22/2020, 06:57 PM | 1 answer(s)

What size is this turbo compared to? Bigger or smaller than a gt3071r and what are pros and cons compared to gt3071r??

Asked by Greg  | 08/07/2020, 08:25 PM | 1 answer(s)

Do we have to get a different oil return line or use oem?

Asked by Devin Obland | 06/11/2020, 05:16 PM | 1 answer(s)

The ~20 psi at 3400-3500 that on a ported head or all oem head work?

Asked by Sasuke | 06/04/2020, 01:35 PM | 1 answer(s)
Mazda performance parts financing is available with CorkSport

Looking to finance your parts purchase and want to get 6 months NO interest on any purchase over $199? Click on the image above for more details.

Some aftermarket downpipes will NOT clear the EWG elbow that is included with the CorkSport EWG Turbocharger.
If the downpipe is not listed here then it has not been test fitted with a CorkSport EWG Turbocharger.

Mazdaspeed 6 Fitment:
CorkSport Catted Downpipe - Confirmed
CorkSport Non-Catted Downpipe - Confirmed

Mazdaspeed 3 Fitment:
CorkSport Catted Downpipe - Confirmed
CorkSport Non-Catted Downpipe - Confirmed
Cobb Catted Downpipe - Confirmed
Depo Racing Non-Catted Downpipe - Confirmed
XS Power Non-Catted Downpipe - Confirmed
Manzo/Ebay Non-Catted Downpipe - Does NOT fit. Will require custom EWG elbow and dumptube
CPe Non-Catted Downpipe - Confirmed
CPe Catted Downpipe - Confirmed


2007-2013 Mazdaspeed 3
  • 2007 Mazdaspeed 3
  • 2008 Mazdaspeed 3
  • 2009 Mazdaspeed 3
  • 2010 Mazdaspeed 3
  • 2011 Mazdaspeed 3
  • 2012 Mazdaspeed 3
  • 2013 Mazdaspeed 3
2006-2007 Mazdaspeed 6
  • 2006 Mazdaspeed 6
  • 2007 Mazdaspeed 6
2007-2012 Mazdaspeed CX-7
  • 2007 Mazda CX-7
  • 2008 Mazda CX-7
  • 2009 Mazda CX-7
  • 2010 Mazda CX-7
  • 2011 Mazda CX-7
  • 2012 Mazda CX-7