The CorkSport CST4 – The Best Turbo for the Mazdaspeed

How to get 400whp from your Mazdaspeed 3

Back in 2015, CorkSport announced the launch of the “CorkSport Turbo” or “CorkSport 18G” a high performance drop-in turbo upgrade for the MazdaSpeed 3, Mazdaspeed 6, and CX-7. Fast forward to 2020 this potent turbo is now called the CST4 with the introduction of the CorkSport CST5 and CST6 Turbochargers.

The CST4 has found home in thousands of community members Mazdaspeeds since launch and continues to be a highly sot after upgrade today…a testament to the CST4’s performance and durability. Starting from scratch, the CST4 is a 100% brand new performance unit.  No core, no revised K04 parts…this is a performance turbocharger from the ground up.  

A bolt on 400whp Mazdaspeed 3 bolt in turbo

Let’s recap on what makes the CST4 such a great fit for the MazdaSpeed.  A proven MHI journal bearing center section, these offer great cooling capabilities and fantastic reliability, especially when combined with our high performance journal bearings and 360° high performance thrust bearing. The CST4 can seriously take a beating, and does it in a package that fits perfect in the OEM location.

Mazdaspeed 3 Mitsubishi 18G CHRA

Attached to this center section is a compressor and turbine wheel combo that is a little unconventional. Creating boost is a custom MHI 18Gbillet compressor wheel that is rated at 50lb/min while the turbine that drives the CST4 is a MHI TD05H 9 blade design. Compared to a traditional 12 blade turbine wheel, the CorkSport design is lighter weight for faster spool times and less blades for higher maximum flow capacity.

Speed3 turbocharger high flow exhaust wheel

The wheels are wrapped in new housings. On the compressor side there is an OEM diameter inlet to simplify the installing with any intake system you had setup with your K04. The turbine housing maintains the stock flange design for easy fitment with any exhaust manifold and downpipe that bolted to the K04. 

The best mazdaspeed 3 turbo upgrade internal or external wastegate, better than the BNR S3.

So what’s the hype now?  Great question!  The community has pushed this turbo to the limits and has asked for more…with the development of the 500whp CST5 and 600whp CST6 we found that an EWG turbine housing can be very beneficial to boost control.  That development bleed over to the CST4 in the form of a EWG turbine housing for increase boost control and an increase in A/R size. 

Mazdaspeed 3 turbo upgrade dyno sheet

Like the CST5, you can now choose your boost control.  Internal wastegate for a stealth and simple install or go for the EWG turbine housing for extra noise and a little more top end power potential.  The choice is now yours. 

Mazdaspeed 3 EWG bolt on turbo kit

Now what does all of this tech mean for you and your car? If you have a stock block you can easily max out power (~380WHP depending on fuel and bolt-ons) and keep some of the K04 spool you love.  With professional tuning you can keep a safe tune that hits hard and carries power.

The wheel and housing options delivers great response as well as great power. When pushed to its limits on a built block, 20psi was hit at 3300-3400RPM with peak boost around 27-28psi carried to 7000rpm. Obviously this isn’t stable for a stock block but is possible on fully built cars with full bolt-ons and a high flowing head.

Mazdaspeed 3 Turbocharger installation hardware

Both the IWG and EWG options come with a full hardware kit that includes everything you need for install. This means all coolant/oil lines, new gaskets, new crush washers, and even new studs and crimp nuts for both the turbine and downpipe flanges. The EWG setup includes a custom designed elbow for great EWG actuator fitment on MS3 and MS6, and the correct clamp to attach it to the housing. More info to come later on an add-on screamer pipe option.

Bolt on Mazdaspeed 3 EWG dump tube kit

Each CST4 also comes with full CorkSport support, including full color install instructions, a 1-year warranty, and assistance with any questions you may have. We are extremely excited for you all to get your hands on the CST4 and start taking your FBO Mazdaspeed to the next level.  Check out the product listing for full details and to place to order.

Need More information? Check out our video below

We have love for the Cx5 Turbo

Mazda Cx5 Performance Exhaust

With the success of the CorkSport CX-9 axle back, it was time to turn our attention to the slightly smaller little brother, the CX-5. We are proud to introduce the CorkSport 80mm Axle Back Exhaust for the 2017+ Mazda CX-5 equipped with the 2.5T. If you’re looking for a little more life out of your new CX-5 Turbo, read on for full details on how to give your grocery getter some growl.

Mazda Cx5 Performance Exhaust

With our experience with the SkyActiv 2.5T in the CX-9 and MZ6, we had a pretty good idea of the correct balance of volume and tone that would be a good fit for the CX5-T. With this, we ended up with 80mm, mandrel bent piping that feeds through two large flow-through resonators. The large resonators keep the noise and drone down during regular driving yet the larger piping size and flow through design of the resonators ensures you can actually hear your 2.5T when you get on the gas. It’s a throaty and deep sound that adds some much needed excitement to the CX-5. Its not all sound though, the larger piping and flow through resonators are much less restrictive than the OEM muffler section. While we haven’t had a chance to get a CX-5 on the dyno, the 2.5T is definitely breathing easier.

80mm Cx5 Turbo Exhaust System

Aside from the obvious sound benefit, the CS axle back adds a visual boost that looks at home on the rear of the CX-5. The exhaust tips were enlarged to 100mm to fill in the bumper cutouts. They were also extended outward slightly, and a slant cut was added to the end. This gives a stylish and classy look that should’ve been the way Mazda made it! The tips are garnished with a laser engraved CorkSport name badge for a nice finishing touch.

Tig Welded Mazda Cx5 2.5T Exhaust

The entire CorkSport exhaust is made from fully polished 304 stainless steel that is precision TIG welded together. This construction ensures good corrosion resistance and strength to last as long as you own your CX-5. Plus, being fully polished, it looks great if you ever catch a glimpse past the tips. In addition, we supply the hardware and gaskets you need for installation, so spicing up your CX-5 can be done in as little as 30 minutes!

Want to hear the Cx5 Turbo Exhaust? Check out the Youtube Vid below..

Cx5 Turbo Performance Dual Exhaust

There you have it, the new CorkSport 80mm Axle Back for 2017+ Mazda CX-5 2.5T. Be sure to visit HERE for sound clips and video of the exhaust on car!

For all you 2017+ non turbo Cx5 owners, yes this will fit your Cx5. The exhaust note of the axle back will be different without the turbo in the system and will be comparable to our 1st Gen Cx5 axle back.

If you’re still curious, give us a call and we can answer any question you may have!

2018+ Mazda6 Performance Exhaust for the 2018-up 2.5T

Mazda did a great job bringing a turbocharged engine back to the Mazda 6 (Mazda 3 next please?), but may have done too good of a job of keeping it quiet. Say hello to the CorkSport 80mm Cat Back Exhaust and Axle Back Exhaust for 2018+ Mazda6 equipped with the turbocharged 2.5L engine. If you’re interested in waking up your SkyActiv-T in both excitement and power, read on as we breakdown the newest CS exhaust.

As with all CorkSport exhausts, the goal of the MZ6 2.5T exhaust is to improve power and sound by improving the flow of the OEM exhaust. We started by increasing the size of the piping from 60mm to 80mm. That is an increase of over three-quarters of an inch to really help your turbocharger breathe better. In addition, the CS exhaust system eliminates the crushed areas present in the OEM exhaust and replaces the restrictive muffler sections with pass-through resonators. These resonators control volume and drone without affecting power output.

All that extra flow does mean a power increase. In our in-house dyno testing, we saw an increase in 5-6WHP just by bolting on the CorkSport  Cat Back Exhaust. Check out the dyno sheet down below to see. This increase came with no tuning changes, no check engine lights, and the only other mod being the CorkSport Short Ram Intake, which was installed for both tests. With the 80mm piping size, this exhaust is ready to support future modifications and would likely show more power gains with proper tuning.

The CorkSport MZ6T exhaust is more than just function. We went through multiple iterations and designs to ensure the best sounding exhaust for your 6. The finished product ups the volume without being annoying to daily drive yet still sounds great when in hard acceleration. We strongly recommend you watch the video below to hear what to expect from this exhaust.

If you feel the video below gives you too much volume for the daily, then check out the Axle Back Only Exhaust.  Recently added to the CorkSport line-up, the Axle Back alone adds a mellower, but still noticeable tone to the exhaust.  This is a great middle ground between the CorkSport Cat Back and the stock exhaust.

To give a great looking, long-lasting finish to each exhaust, they are manufactured from fully polished 304 stainless steel. To ensure a high quality fitment, all components are precision TIG welded together on jigs made from OEM exhaust components. Lastly as a finishing touch, we use 100mm dual wall exhaust tips. They fill out the bumper cutouts and are extended slightly to give a classy look and enhance the new Mazda 6’s styling.

The CS Mazda 6 Turbo Exhaust comes with all the hardware and gaskets you need for installation, high quality instructions, and CorkSport support for any questions you may have. Pick up a CorkSport MZ6 2.5T Exhaust today and liven up that daily commute.

Guess Who’s Back

We are proud to announce a old product that we have redesigned.  Introducing the V2 CorkSport Coilovers for 2004-2013 Mazda 3 and Mazdaspeed 3.  

We’ve taken the same basic designed and revised and refined it with small changes to fitment and big changes to spring rates and damping rates.

Complete Mazdaspeed 3 Coilover Suspension

For spring rates we took an approach that seems to differ with most street oriented kits on the market today.  We wanted to develop coilovers that were both enjoyable to drive on the street in a daily driven car, but could also perform on the track in more performance oriented settings.   With these goals we focus on the ride feedback, understeer/oversteer balance, and suspension frequency balance.  

The result; linear rate 7K front springs and 8.5K rear springs. This provided us with a ride quality that was comfortable, but sport focused and with the right balance of understeer vs oversteer, with a car that is more oversteer biased.  The frequency of the suspension was also taken into consideration with a higher rear frequency than front to improve driver feedback and comfort. 

Mazda 3 coilover suspension

Like most coilovers, ride height adjustability is essential to setting up you Mazdaspeed 3 or Mazda 3 for your goals.  The redesigned CS coilovers offer 2 inches of height adjustability from approximately 0.75 inches to 2.75 inches lower than stock springs.  This range of ride height allows you to have a conservative track-oriented setup or a slammed show setup depending on your goals. 

With ride height, you can also adjust the front camber setup with the CS Coilovers include front camber plate, this kit comes to your door ready to install.  

Street Performance 1st Gen Speed3 Coilovers

Lastly, and also somewhat unique to CS, is the design of the front coilovers.  Instead of a more conventional and cost effective design, we’ve utilized an inverted damper design for improve performance.  By inverting the front damper/shock, we’ve both reduce the unsprung weight of the front suspension and increased the rigidity.  Both of these result in increased driver feedback and improved performance.  

2nd Gen Mazdaspeed 3 Suspension

If you been considering lowering springs or coilovers for you Mazda 3 or Mazdaspeed 3 then give CS a good look. Thanks for taking the time to checkout CS, stay connected on the blog, newsletter and social media channels for upcoming performance parts for your Mazda.  

-Barett @ CS

Zach’s Road to CorkSport

The Journey to CorkSport

Ever wonder what it was like to win the lottery. You ever let your mind wander and think what it would be like to actually “Live the dream.” I know I have, well, until I joined CorkSport! My name is Zach Sprague, and I wanted to share with you my experience of joining, what I believe to be, the best well known and respected company in the Mazda Community. Let’s take a look at my journey.

I’ve always been into cars and have had a pretty big obsession with FWD Hatchbacks. My passion for this platform started back in 2014. I sold cars for Toyota in Southwest Washington for about four years. During my tenure, I drove some pretty amazing vehicles, one of them being a 2013 VRM MS3 Tech pack. I knew what a Mazdaspeed was, a Turbo FWD Hatchback, and at that time that was more than enough to pique my interest in the platform. It was temporarily sitting on my lot, and I had to drive it back down to Portland to our sister store.

Before jumping into the seat, I didn’t know any horsepower or torque figures. I didn’t know what kind of emotion it was going to spark when I drove it. I had NO idea that it would become the screen saver on my computer. I slid in and pushed the button. (You know those Cold Starts) This car’s exhaust made my heart drop and gave me goosebumps. I honestly felt like an 8-year-old on Christmas Morning. 

Once on the ramp, I slowly shift into third at about three and a half grand on the tach and just sent it. Torque steer was prevalent as I was gently pushed back into my seat. I slammed 4th, and I hear this intoxicating PSSHHHHHH. I was done, I was hooked, addicted and didn’t know what to do with myself. I was so intrigued I stopped at every rest stop on the way down so that I could feel this car accelerate back onto the freeway. <insert uncontrolled giggling here>.

Flash forward a couple of years, and a guy I worked with, now one of my best friends, went out and bought a VRM Speed6. Everything on that car from top to bottom was stock down to the wheels. I slowly watched his build progress over the year and transform into one of the most inspiring builds I have ever seen. In that time he was kind enough to let me pick his brain about these cars and what they like, what they don’t like.

In 2018 this is when things got interesting! After a few months of looking and 100 YouTube videos later, I was finally ready to pull the trigger on one of my bucket list cars. I snagged a 2013 MazdaSpeed3 in liquid Silver. I drove almost 4 hours and paid an arm and a leg for sales tax, but it was worth it.

Miles of Smiles 

I was grinning ear to ear the entire way home; 4th gear dumps on the freeway, testing the grip of the tires out at a few stoplights, full-on shenanigans. I tell you what; I made it home a lot quicker than the drive up.  

I had the car for 3 weeks before I added my first mod. I already had a vision for the car, but first things first, I had to take care of those sloppy shifts. My shifter bushings and short shift plate showed up from CorkSport. At that time I knew they made great parts and were one of the very few places that even made parts for this car. What a difference that made! It felt robust and more responsive.

The Opportunity of a Lifetime

I always joked with my friends about working for a company like CorkSport. I just thought it was this elusive dream that I’d be sitting behind a desk helping other people build their dream cars. I never thought in my life that an opportunity like this would come into fruition. 

My buddy, who helped me get into Mazdaspeeds, sent me a message on FB, letting me know that CS was hiring. I thought to myself; this is no lie. “There is no way on god’s green earth I’d ever get that lucky.” However, I applied. What’s the worst thing that could happen, right? 

CorkSport isn’t a revolving door, and the team is made up of a close-knit group of professionals that also happen to be car nuts. They carefully consider who’s going to be a good fit with their existing team and identify candidates that are going to get the right shit done well. I knew this was a different company, and their standards were high because they didn’t just accept my resume; there was a pre-test.  

A funny little story. I got a message from CorkSport saying they wanted to set up a phone interview! I couldn’t believe it! That Friday, I called to set up a meeting for Monday. This is where the humor known as my life kicked in; I BROKE MY PHONE ON SUNDAY! *RED ALERT* My dream job was calling me on Monday, and I didn’t have a phone, so I went out and bought a little prepaid flip phone. 

Although I almost missed this opportunity, it went well enough for CorkSport to schedule a second interview over Skype. I must add, this occurred over two weeks. I was losing my mind; I couldn’t believe it was happening. All my buddies knew I had the job, they knew how obsessed I am with cars, especially my speed 3. I still was in shock couldn’t believe I had my second interview.

When CorkSport called me to let me know, I had a final interview with the Company’s President, Corey – Hello nervousness, glad to see you again! I can’t put into words how excited I was; it was pure bliss and absolute disbelief. “IS THIS REALLY HAPPENING!” I screamed at the top of my lungs when I got off the phone. I showed up a half-hour early. It was cool; I got to meet someone I’ve stalked on Instagram for a while and who has been a significant influence on me since I got into the Mazda community – Brett White.

It’s so surreal when you get an interview for a job you’ve always wanted. Above all, I remember from the interview is telling Corey, “Even if I don’t get the job, knowing I made it this far and am sitting here with you having this interview is honestly a dream come true.” It’s unreal to think that one mistake, such as breaking my phone the day before my first interview, could have kept me from writing this blog for a company I’ve looked up to since I’ve been into Mazda’s.

I cannot believe I’ve been here a little over a year already! It’s a fun environment where everyone is looking out for one another. I’ve been able to FLY in the fastest thing I’ve ever been in (Barett’s monster Gen Juan), and had the chance to drive a car I’ve drooled over on social media (Brett’s Baby) for years. 

Barett’s monster Gen Juan

Looking back, it wasn’t even four days after joining the company before the guys a CS put lowering springs on my car. It took a little over a week for me to buy an AccessPort and a Dual VTA Bypass Valve, and that was just the start! You don’t want to be an employee driving a stock Speed with a CorkSport Sticker on it.

Stay tuned to see where CorkSport and I go with my car. I’ll catch you on the flipside and, thanks for reading my first blog!

Zäch Fröm CorkSport