See Daniel’s “SPDBOAT” Mazdaspeed 6 Build Part 1

Hey everyone, this is Daniel, one of the engineers at CS. In case you don’t know me (I’m quiet on socials, but I’m working on that!) I’ve been with CorkSport since the middle of 2017, so I’ve probably had my hands on any product released in the last five years. For example, the exhaust manifold for the Mazdaspeeds was my baby for a while, and I’m still super proud of how it turned out. In this blog I’ll be going through my Speed 6 build. It has been a long time coming, but it is finally getting close to how I want it!

Mazdaspeed 6 at car show with lowering springs and brake kit
Daniel’s Mazdaspeed 6 at HIN

I got my MS6 back in January of 2018. It was a bone stock 2007 Sport with ~68k miles, but I got a decent deal due to some scratches/dings from the previous owner’s kids. I was familiar with the Speed6 because a high school buddy bought one shortly after we graduated, so I had been looking off and on since I started at CS. Since we didn’t have one in the fleet at CS then, and I wanted the AWD, it was an excellent fit for me. In typical speed fashion, I got a check engine light on the ~2-hour drive home from where I bought it! Clearing the CEL would require an EGR cleaning before I could register it, but I was still in love, despite the stock wheels & monster truck ride height.

Mazdaspeed 6 project build
Daniel’s Mazdaspeed 6 Before Modifications

From humble beginnings, the modifications started slowly. The first six months were the “basics”; HPFP internals, downpipe, exhaust, lowering springs, upgraded TMIC, and plasti-dipped stock wheels. I was still surviving on the stock intake and using the OTS tunes on the Cobb Accessport – standard new Mazdaspeed owner things. I completed a VVT replacement at around 70K miles as the chain started hitting the valve cover, but then things started getting interesting.

Mazdaspeed 6 black in stance
Black Mazdaspeed 6

Just before the 1-year of ownership, my stock K04 turbo began smoking as expected. Being the only Mazdaspeed 6 at CS meant my car was in the shop off and on for R&D, so I took advantage of one of the early exhaust manifold test fits to throw in a CST4 Mazdaspeed Turbo (still known as the “CS 18G turbo” back then), a 3.5” intake (with a custom & very early prototype of the Mazdaspeed 51R battery box), a few other supporting mods, and some special sauce from Erik @ Dramatuned. So just before my car’s birthday, it was FBO minus manifolds. Somewhere in there, I was also the guinea pig for the CorkSport 330mm Big Brake Kit on the MS6 (still one of my favorite mods to date) and some wheel spacers to clear.

Image: CorkSport-MS6-BBK

Mazdaspeed 6 big brake kit

2019 was a bunch more R&D for the Mazdaspeed 6 platform. I spent a few months driving around without a front bumper during the MS6 Front Mount Intercooler development! Then came some even more fun stuff. I was able to snag some early production run intake manifold and exhaust manifold along with an EWG setup (Exhaust Manifold, Tial, and Dumptube). Finally, I was “full bolt-on” and completed tuning. While its v-dyno was a little overestimated, here’s an idea of power to expect for a similar setup on pump gas (red line) and on a couple of E mixes (the blue line was E30, green was E25). Ethanol is worth it!

Dyno data for a Mazdaspeed 6
Black Mazdaspeed 6 with engine bay open

After having gone through most of the CorkSport catalog for power mods, I began to do a few aesthetic mods, which is where the “SPDBOAT” plate came in, a simple play on Mazdaspeed and how heavy and “boaty” the cars can feel at times. It’s dumb, but I love it! Also came some miscellaneous mods. An upgraded rear sway bar, diff mount, as well as the transfer case, and rebuild with billet bearing caps all were added.

Mazadaspeed 6 in black at boat dock
Daniel’s Mazdaspeed 6 SPDBOAT at the Lake

By birthday number two, a long-awaited wheel setup was introduced. Initially, I ordered a set of Gram Lights that would’ve fit without too much effort. However, after many issues and shipping delays, I canceled that order and went something much more aggressive. I settled on 18×9.5 Enkei GTC01RR wheels on a 255/40 tire. I was going for meaty with this setup, and it looks great. After a fender roll all around, camber, and spacers in the front to clear brakes, final offsets are +35 front, +42 rear with ~2.5 degrees of negative camber. There’s only so much wheel and tire you can fit without more intense modifications, but the handling boost was amazing!

Close up of modded Mazdasped 6 with upgraded wheels and CorkSport Big Brake kit
Enkei GTC01RR Rims for the Mazdaspeed 6

I ran the car on this setup for another year. This configuration was a great “all-rounder,” and I loved it. Not perfect at any specific thing, but a great daily that’s fun in the corners, decent enough to go to a show, and with enough power to do well on the occasional trip to “Mexico.” But then, it started consuming oil. Just after my third year with the car (early 2021 for those keeping track), I found cylinder four down about 40psi of compression and cylinder 1 with about 20% leak down. Still working fine, but eating about of quart of oil every ~600 miles meant it was time for a rebuild.

Mazdaspeed 6 Black photo
Mazdaspeed 6 at Mazda Takeover

While I hate to leave on a cliffhanger, that’s the end of part 1. Stay tuned for part 2, where things get spicy, including a built motor, a bigger turbo, and a broken bone…?

I hope you enjoyed my tale, and please let me know if you have any questions. By now, I know more than I need to about the MazdaSpeed 6!


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Sneak Peek of the Upcoming Rear Hatch Brace for the 2019+ Mazda 3

We are excited to let you in on the Rear Hatch Brace (RHB) development process for the 4th Gen Mazda 3 Hatch!

This project began after slaying the Tail of The Dragon’s 318 curves last October. We determined that the new Mazda 3 would benefit from additional bracing, and we are currently testing the first round of prototypes. In this blog, we will go into the development process of the Rear Hatch Brace and the steps we took to get to our current sample, which will be the design you can purchase for your hatch in the coming months.

This project began by searching for suitable mounting locations to tie the brackets and cross bars into the chassis effectively. After removing a good amount of the hatch trim panels, we found that the existing mounting locations for the seat back latch were a perfect spot to use as the location for the main cross bar brackets since they are tied into a main chassis structure. They also feature two M10 bolt locations perfect for providing a secure bracket mounting point.

After we nailed down the main cross bar’s mounting locations, we looked for another spot to tie in additional bars required to triangulate the brace. The bracket that links the rear seats back together was an obvious choice since it also offered two M10 mounting locations that were easily accessible. The CAD model depicts the brackets below, which are highlighted in blue.

mazda 3 turbo performance parts rear brace

Once we identified all the mounting locations, the next step was to move on to designing the brackets and cross bars. This process was considerably easier since we created the parts using the Mazda 3 hatch chassis in CAD, as seen above. The first components to be designed were the brackets. The brackets needed to match the angle of the rear seats without sticking out too far into the storage space to retain the practicality and usability of the hatch.

Retaining practicality is also the main reason why we wanted the brackets and cross bars to be separate. If you ever need to remove them for additional space, it can be done quickly without removing any trim pieces. We also wanted to provide two configurations or “Stages” of the RHB to give you more options. Once all these constraints were taken into consideration, it resulted in our bracket design, which is currently being tested on one of our shop cars. Below you can also see a comparison between the CAD model’s Stage 1 and 2 configurations.

Stage 1 – Single Bar System

turbo mazda 3 performance part chassis bracing stage 1

Stage 2 – Triple Bar System

turbo mazda 3 performance part chassis bracing stage 2

For the design of the cross bars, we initially started with an alternative design and material. The first iteration of the cross bars featured a round tube that would be welded to bent sheet metal end brackets to provide a mounting surface to interface with the brackets attached to the chassis. While this design would have been functional, it looked less OEM than we wanted. Additionally, it would have added considerable difficulty to the RHB’s manufacturing and overall cost.

We decided to search for a better solution that would function as expected while also improving in the areas the previous design lacked. Over the course of the design process, we moved to a rectangular tube as the stock material. The R&D process resulted in the rectangular cross bars we are testing on the car now. A comparison between the two designs is highlighted in the images below.

Mazda 3 turbo performance bracing for hatchback
2023 Mazda 3 turbo hatchback rear bracing parts  

The last detail of the Mazda 3 Rear Hatch Brace is all the hardware tying the brackets and cross bars together, along with the coating used on the parts. For the hardware, we wanted to provide bolts that matched the clean look of the brace and complemented the look we were going for. That led to us selecting countersunk bolts and finishing washers which are stainless steel for excellent corrosion resistance and help add the extra flare we were shooting for. The cross bars and brackets are textured black powder coat, further complimenting the factory interior while providing a rugged finish. As you can see below, the results are beefy!

2021 Mazda turbo chassis scanned data

Mazda 3 hatchback rear hatch brace installed

Thank you for reviewing the details of the design process of the CorkSport Rear Hatch Brace. If you are interested in picking one up for your 4th Gen Mazda 3 Hatch, stay on the lookout – it will be hitting the website in the coming months.

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Race Better with the Mazda 3 Transmission Gears Upgrade

Racing is brutal! When pushing a vehicle to the razor’s edge, you tend to find the platform’s limitations rather quickly – then set out to overcome them! This is precisely where the CorkSport 3rd & 4th Upgrade Gears come in. 

Mazda 3 manual transmission gear upgrade

In the years of racing our Touring Car class Mazda 3, we found many pitfalls that have been easy to overcome. However, we found the gears’ limit with the 317whp/355wtq of the CorkSport Turbo Kit pumping through the manual transmission. Pair that with a limited-slip differential and wide sticky racing tires…well, it’s shocking the drivetrain has held up as well as it has.

Mazda 3 TC Racecar performance parts

Destroying a transmission during a race weekend was not a viable path to success, so we developed our own race-quality CorkSport High Strength Gears to solve the problem. As you might imagine, this posed some significant challenges. For example, to retain the 6-speed setup, we had to stick with the same gear widths – which are very narrow.

Mazda 3 performance upgraded gears manual transmission

To gain the strength and durability needed, we opted to use a higher strength material; SAE9310 steel, and to further increase the durability, the surfaces are shot peened. The shot peening process helps durability by reducing the chances for stress cracks to develop, increasing fatigue life and bending strength.

mazda 3 racing full send with gears

Since then, we have been running these gears in our TC Racing Car for a complete season to validate that there are, in fact, better than OEM. Racing is the ultimate test for performance parts, and we are happy to report the transmission has caught every shift!

So why might you need these upgrade gears?  Do you have a turbo or supercharger kit on your manual Mazda 3 or Mazda 6?  Do you like driving your car hard and even doing some structured racing events? If yes, these may be in your future, so you can push your Mazda to the limits without worrying.

Thanks for tuning in!

Barett @ CS

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Dial in Your Mazda 3 with the Performance Toe Arms!

Control is key when it comes to pushing your Mazda to the limit…that’s exactly what CorkSport has set out to give you with the new CorkSport Rear Toe Arms for your 2014-2018 Mazda 3 and 2013 and newer Mazda 6.  Control, precision, & strength define what the CS Toe Arms are all about; let’s see why. 

CorkSport ASdjustable Toe Arms for your 2014-2018 Mazda 3 and 2013 and newer Mazda 6

The Adjustable Toe Arms overall construction provides durability and control which come from the high-strength steel that is coated in an awesome CS blue finish.  Durability is not an issue with the CorkSport Toe Arms (more on that later). 

Blue Adjustable toe arms for the Mazda 3 and Mazda 6

The Toe Arms Replace the OEM rubber bushings providing strength to your Mazda.  Factory rubber bushings are soft and compliant…great for a grocery getter, but not great for the spirited driver.  The CS design replaces this flimsy bushing with a rigid spherical rod end to remove that compliance and give you a solid and planted feel from the back of the car.   

Pair these with CorkSport Camber Arms and you’ve effectively removed half of the soft rubber bushings from the rear suspension.  You will notice this in how the car feels and drives. 

Lastly, the adjustability of the toe arms puts you in control of your driving performance.  You have more than enough range. from OEM to 2.5+ inches,  to dial in the rear toe of your Mazda 3 or Mazda 6.  Being able to adjust the toe independent of camber and track provides.  You have full control of the setup which can help with handling and tire wear significantly.

Now back to the durability testing.  We push our parts to the limit on the track so you can have confidence with your Mazda.  The CorkSport Powered Mazda 3 TC car, equipped with our performance toe arms, is being pushed to the limits in Turn 4 of the Indianapolis Motor Speedway Road Course.  The track pushes the toe arms to the limit. Enjoy!

Put your confidence in CorkSport for your Mazda needs.  Let us know if you have any questions! Our knowledgeable team would love you hear from you!

FAQs About Rear Toe Arms

What do adjustable rear-toe arms do?

Adjustable toe arms are one of the multiple suspension arms that connect your wheel bearing hub to your vehicle chassis.  The arms allow you to fine tune the angle of the wheel & tire relative to the chassis for optimal performance.  This results in greater steering response, control in turns & maneuvers, and increased tire tread life.

Do you need rear toe arms?

Yes, if you are a spirited driver, racing driver, or looking for more control.   Adjustable toe arms also help resolve the uneven tire wear that often results from aftermarket lowering springs and coil overs.  OEM suspension arms have very limited range or no range to correct the new angles caused by the installation.  

CorkSport TC America Car Racing with Performance Toe Arms

How do rear toe arms affect handling?

Toe arms improve handling by changing the angle of wheels when looking from directly above the vehicle.  In performance, the toe of your tire may point out or in when modifying your vehicle. By having the flexibility to set your vehicle alignment, you are able to adjust the toe-in or toe-out position to reduce understeer or oversteer and improve handling at high speeds or through tight corners. 

CorkSport TC America Car Racing with tight turns with Performance Toe Arms

Are adjustable toe arms worth it?

Upgraded toe arms improve the quality of ride, reduce flex in the suspension, and provide more control in high speed and tight turns.  Aftermarket suspension modifications can often create uneven wear and tear if supporting parts like toe arms are not used.  Adjustable toe arms solve this issue and extend the life of your tire.  In addition, the higher-strength metal provides durability and more responsiveness in handling. 

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The Good, the Better, and the Best Upgrades for Your Mazdaspeed

The good, better, and best upgrades for your Mazda.

Think back to the first day you bought your Mazdaspeed. I’m sure for most people, it’s a day you’ll never forget. What was your first thought about the car? I know my first thought was, “What aftermarket parts can I install on my speed?” Let’s be honest, when it comes to the boost bug, the bug always gets you. One can’t simply own a Mazdaspeed and not modify it. It becomes an addiction, a way of life.  If you’re like most Mazdaspeed owners, you can’t settle. You want to make sure you’re getting the best parts possible. So, where do you start when it comes to adding modifications to your speed? There are many ways to increase power with the Mazdaspeed platform, but finding the correct path can sometimes be a challenge!

Once you’ve bought your Mazdaspeed and you’re looking for the correct path to take, there are some specific modifiers you want to make sure you do first. If you have a goal of making your speed a fully bolted machine, the first thing you want to do is upgrade the fuel pump internals.

Save $35 off the CorkSport Mazdaspeed Fuel Pump internals when purchased at the same time as the COBB Accessport


Everyone wants more boost, and with more boost comes the demand for added fuel. With that demand, you need to make sure your fuel pump pressure doesn’t drop below 1600psi. Some people can get away with doing big power modifiers without upgrading the fuel pump internals, but it’s highly recommended not to push your luck. A small investment to upgrade your fuel pump internals or drop the cash for a new motor because your fuel pressure dropped below 1600psi at WOT. Take your pick! The CorkSport Max Flow Fuel Pump Internals Kit is the safety net you need on your builds list. This kit adds up to 50% more fuel, which is perfect for people looking to get their speed fully bolted. Once you’ve installed the fuel pump internals, you’ll be able to safely reach horsepower numbers of around 350-380whp without any other modifications to the fueling system.

Now that you’ve successfully upgraded your fuel system, you’re ready to start making some power. One thing to keep in mind when doing modifications, is that the ECU needs to recognize your added modifiers such as a FMIC, down pipe, full intake, or any other performance part that will increase hp/tq. There are a few ways you can do this, but using an AccessPort is the most popular tool used on the Mazdaspeed platform.


Not only does the AccessPort allow someone to customize a tune based on modifications made, it’s also a great tool for monitoring different kinds of parameters as well as reading and clearing check engine light codes. You’re able to fully customize a tune for your car and make sure the car is running safely. Whether you want to have a fun street car or a full-out track car, the AccessPort is a must for any speed owner looking to add power modifiers.

Now that you have the proper fueling, and an AccessPort to make tuning easy, you can do anything you want to your speed. With that being said, my next modification recommendation would be a full intake for your vehicle.


Besides the fuel pump, the intake has one of the biggest restrictions for the turbo. Not only are there too many hoses running the stock intake, the turbo inlet pipe is designed flat like a pancake which chokes the turbo under load. By installing our stage II SRI, you remove the hoses, air box, and pancake turbo inlet pipe making the overall efficiency of the turbo much better. You may also see an increase in boost psi which is something we’re always trying to increase. After you’ve purchased and installed the intake, you will notice an overall increase in power and sound. A must-have for someone looking to start with a great power modifier.

These recommended first mods would be considered the good, better, and best modifications to start with if you’re ready to start modifying your Mazdaspeed. With fueling no longer an issue, having a way to tune your car, and allowing the turbo to breathe, you will definitely start to notice a gain in power, sound, and overall love for your Mazdaspeed!



Luke McCarvel-01