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Vancouver, WA


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

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EWG Upgrade Kit - CST4 & CST5 Turbo

Price: $399.99
Price in points: What are Points?400 points
Switch to an external wastegate on your CST4 and CST5 using the CorkSport EWG housing. Designed for Mazdaspeed Turbo
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External Wastegate Turbo Housing

Utilizing an External Wastegate with your CorkSport Turbo just got a whole lot easier! Introducing the EWG Turbine Housing for the CorkSport CST4 or CST5 Turbos. This will allow you to replace your internally wastegated hot side and utilize an external 44mm wastegate. The external wastegate will bolt to the hot side of the turbo with the included elbow and V-band clamp.

Benefits of going with EWG are better boost control, ease of accessibility to service/change the springs and amazing screamer pipe noises!

Externally Wastegated (EWG) hot side set up includes the necessary EWG installation elbow pipe & V-band clamp.

Don't forget the direct-fit dumptube for a quick and easy install. No custom fabrication needed and you save $10 if you buy now.

Mazdaspeed 3 EWG Exhaust Housing Kit
The CorkSport Advantage
mazdaspeed 6 external wastegate turbo housing

Performance Focused

The CorkSport EWG housing takes our already great CST4 and CST5 turbine housings and optimizes them for use with an external wastegate. Not only do you get the port itself to run the EWG, swallowing capacity has been increased to maximize peak exhaust flow. The CST4 gets an A/R change as well, moving from the 0.66 with the IWG housing to 0.82 with the EWG. While there is a very minor spool penalty, you gain increased power potential!

mazdaspeed external wastegate housing

Fitment Inspired:

The EWG port location was specifically chosen to optimize EWG functionality. With the EWG inlet tangent to the scroll of the turbine, we gain fantastic boost control and allow clearance for the OEM oil drain line. Coupled with the supplied elbow and clamp and you get the flexibility to work with most downpipe setups!

mazdaspeed3 external wastegate housing

Materials & Manufacturing:

Like all our other turbine housings, the CS EWG housings are made from cast high silicone molybdenum that is resistant to heat cycling cracks and will stand the test of time. The supplied elbow and optional dumptube are both made from T-304 stainless steel and TIG welded together. Even the supplied v-band clamp is stainless steel! Finally, each v-band flange is precision machined for perfect fitment and a great seal.

Additional Features
  • Compatible with:CorkSport CST4 Turbocharger & CorkSport CST5 Turbocharger
  • Designed in America: Designed in Vancouver, Washington, in the Pacific Northwest.
  • CorkSport Service & Support:Receive a 1-year warranty, full-color installation instructions, all of the needed installation hardware, and knowledgeable telephone installation support.
  • External wastegate is NOT included.
  • EWG designed for 44mm TIAL or equivalent external wastegate.
  • 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 Turbine Housing. Check the "Fitment Notes" tab for details.

How To Install Your CorkSport EWG Housing

It will take you 5 hours to install the CorkSport EWG Housing with our easy-to-use instructions.

installation instructions
5 Hour Install Time

5 Hour Install Time

Difficulty: 4/5

4/5 Difficulty

1-Year Warranty

1-Year Warranty



I got a cst4 iwg and the short downpipe to racepipe to hks catback and im thinking of getting the ewg housing. Will the short dowpipe be restrictive because of the split tubing at the beginning?

Asked by José Colón Rosado | 08/29/2023, 10:13 AM | 1 answer(s)

I have a BNR S4 turbo v2. Would this housing fit on my turbo?

Asked by Tyler Lang | 12/13/2021, 10:43 AM | 1 answer(s)

i got a cst4 but want to run external waste gate off the exhaust manifold, How can i make this work?

Asked by adarsh  | 08/11/2020, 02:14 AM | 1 answer(s)

does this fit with a stock downpipe

Asked by jason | 08/01/2020, 06:11 AM | 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