Author: Derrick Ambrose

Posted on

Best Mazdaspeed Turbo Upgrades – Choose Your Boost

May of 2015, CorkSport launched its first high-performance drop-in turbocharger for the Mazdaspeed platform.  Fast-forward almost 4 years, and CorkSport is again about to redefine what a stock flange turbocharger for the Mazdaspeed platform can indeed be.

The Best 400 WHP for the Mazdaspeed  

The original “CS Turbo” is now the CST4 Mazdaspeed Turbo to follow the turbo line-up. It is the best turbo used to upgrade the OEM K04 Mazdaspeed Turbo. The CST4 took a fresh approach to “big turbo” with all the included hardware, gaskets, and, direct drop-in fitment.  It removed the guesswork for a quick and easy installation, but the benefits didn’t stop there. This “little big turbo” packs a punch for its compact TD05H-18G wheels.  We think it’s best for Mazdaspeed turbo to get started.

Best Mazdaspeed 3 Turbo K04 Upgrade for 400 WHP
Best Mazdaspeed 3 Turbo K04 Upgrade for 400 WHP

With the CST5 and CST6 just around the horizon, it would be easy to forget about the tried and true CST4, but don’t worry this Mazdaspeed Drop-In Turbo got some new love making it one of the best turbos on the market.  You will now have an EWG housing option for the CST4. You can pick it up in EWG setup from the start or if you already have a CST4 that you love, you can get the EWG housing kit to do the upgrade yourself.

Moving onto the CST5 & CST6 the possibilities for the MZR DISI have moved up significantly.  What started as a single “bigger big turbo” has morphed into two “bigger big turbos” that, we feel, better provide for the various power goals of the community.  

Best 500+ WHP Mazdaspeed Turbo

We present to you the CST5

CST5 is the Best 500+ WHP Mazdaspeed 3 Turbo

The CST5 Turbo bridges the gap between drop-in performance and Mazdaspeed’s big turbo power.  The journal-bearing CHRA uses a hybrid TF06-GTX71 wheel setup that provides more top-end than the CST4 with minimal spool and response penalty.  Upping the big turbo feel is a 4-inch anti-surge compressor inlet which will require an up-sized intake system.

Unlike the CST6, the CST5 turbo will be offered in internally waste-gated and externally waste-gated setups.  This provides you with the flexibility to set up your Mazdaspeed just how you see fit and both have been proven 520+ whp on our in-house dyno and tuning courtesy of Will Dawson @ Purple Drank Tuning. This has been the best turbo to achieve 500 WHP.

The Best 600+ WHP Mazdaspeed Turbo

Now… We present to you the Stock Flange Record holder…the CST6

Best Mazdaspeed 3 Turbo for 600 WHP

The CST6 redefines what the community thought was possible from the stock turbine housing flange, but first some details.  The ceramic ball bearing CHRA uses a GTX3576r wheel setup that clearly outpowers the CST4 & CST5, but that’s the point remember?  

The Mazdaspeed CST6 Turbo is a legit big turbo. The spool will be later, but still below 3900rpm for the full boost! However, a turbo setup is not intended for low-end response.  If top-end power is your goal, the CST6 is the best turbo for your Mazaspeed and will deliver. In-house testing has pushed the CST6 to 633whp at a fuel limited ~33psi and 7900rpm redline.

Unlike the CST4 & CST5, the CST6 will only be offered in EWG setup.

Best Mazdaspeed 3 EWG For Turbos CST4, CST5, and CST6

In the coming months, we will share more information about the CorkSport Turbo Line-Up; the design, the testing, and validation of each.  Check out these pages for more information about the Mazdaspeed CST5 Turbo & CST6 Turbo along with the new EWG turbine housing option. Get and boost on!

Thanks for tuning in with CorkSport Mazda Performance.

Connect with us

Stay up-to-date on the latest news and product updates from CorkSport.

* indicates required

You may also like:

Posted on

SkyActiv 2.5T Cold Side Boost Tube Part 2: Testing

In case you missed it, we have been working on improving the flimsy rubber tube that comes stock on the cold side of your 2018+ Mazda 6 2.5T. Check out the first part on the cold side boost tube here and the full OEM piping & intercooler breakdown here. Since our last installment, we have been busy testing a prototype CorkSport Boost Tube and would like to share some results with you all.

Testing Results

SkyActiv 2.5T Boost Tube
CorkSport SkyActiv 2.5T Boost Tube

Starting off we tested and data logged both the OEM tube and CorkSport Performance Boost Tube on the dyno. We were not expecting to see too much of a difference to power with just the boost tube changing however, we did see tiny improvements here and there, most notably way up at the top of the RPM range.

Check out the graph below, (OEM: red, CS: green). We tested on the same day in identical conditions and the car had a CorkSport Intake and Cat Back Exhaust installed for both tests.

PLEASE NOTE: the variations below 2800RPM are due to inconsistencies associated with dyno testing an automatic car.

SkyActiv 2.5T Boost Tube Performance Dyno

After noticing these changes, we went to the data logs to see how the boost changed between the OEM tube and the CS Mazda 6 Boost Tube. The graph below shows the engine RPM versus the manifold pressure in psi. Both lines have the same smoothing done to the raw data. As you can see, the CorkSport tube (green) holds about 0.5psi through the midrange (3500-5000RPM) and is almost 1psi more when above 5500RPM. This correlates well with what we saw while dyno testing.

SkyActiv 2.5T Boost Tube Manifold Pressure Test

Testing the Changes

The small increase in boost pressure is likely due to the CorkSport tube not expanding as much when under pressure. To confirm this, we capped off both ends and pressurized each tube to 20psi. Note: do not try this at home as the caps can easily fly off and injure you.

Boost Tube being tested

After measuring multiple locations both before and during pressurization, we found that the OEM tube expands about 12% in the internal cross-sectional area while the CorkSport Boost Tube expands 3x less at 4%. Keep in mind that this would be an even larger difference if the same test was performed with the tubes installed on the car due to the heat of the engine bay. Since silicone is more stable than rubber at high temperatures, the heat of the engine bay will not soften it nearly as much as the rubber OEM boost tube. A softer rubber tube would mean even more expansion when pressurized and even more inconsistent boost pressures.

CorkSport and OEM Boost Tube Comparison
CorkSport Boost Tube (left) & OEM Boost Tube (right)

This data may not show drastic changes but it does not tell the whole story. The larger diameter and thus larger volume of boosted air of the CS tube provides a little bit better response when low in the RPM range. While this may just be a placebo effect on our end, there’s not too much of a wait before you can try it yourself! Stay tuned for more information. If you want a more serious upgrade though, keep your eyes out for information on the upcoming CorkSport Front Mount Intercooler kit and Piping Upgrade kit!

P.S. 2016+ Mazda CX-9 owners and future Mazda CX-5 2.5T owners, don’t worry we will be checking this for fitment along with other CS goodies!

-Daniel @ CorkSport

Connect with us

Stay up-to-date on the latest news and product updates from CorkSport.

* indicates required

You may also like

Posted on

80mm Gen3 Mazda3 Cat-Back Exhaust

CorkSport 80mm Exhaust Installed
CorkSport 80mm Exhaust Installed

4 years ago, we released the 60.5mm Exhaust kit for the 3rd Gen Mazda 3 (both in axle back and full cat back flavors). It’s certainly been a hit, but there have been a few of you longing for more noise. Today we are proud to announce the 80mm variant of our cat back exhaust for the 2014-2018 Mazda 3 Hatchback and Sedan! At this time, just the hatchback version is available, but we will have the Sedan version ready in just a few short months.

The Dirty Details

CorkSport 80mm Cat Back Exhaust Exhaust
CorkSport 80mm Exhaust Installed

Now I know what you’re thinking, an 80mm exhaust for Mazda 3 seems excessively large for a naturally aspirated car making less than 200whp. But, hear me out because I think you’ll like what’s coming.

80mm piping allows for some unique & louder tones its smaller little brother can’t offer, but it wasn’t as easy as just using the old design and making the pipes larger. We had to do quite a bit of resonator experimentation and NVH analysis to get to the finished result with as little drone as possible. I’ll be upfront with you guys though, this is loud. It’s a good loud with tons of fun noises, but if you’re looking for something subtler, then our 60.5mm cat back or axle back may be a better fit. We do a good job of capturing the audio for you though so you have a good understanding of what you’re getting. Be sure to check out the product video to hear it.

Listen Now!

The Beauty of the Design

For those wanting this more aggressive exhaust note, sound isn’t the only bonus. We thought about the appearance, and how we could take advantage of this time to tinker with the design. The 80mm does a nice job of not only filling the exhaust tunnel under the car, but the axle back portion is a bit more prominent when you catch a glance.

On the Hatchbacks, the exhaust tips got a nice size increase up to 100mm and they are slant cut to help follow the profile of the bumper. Sedans have also been upsized to 100mm tips, which were lowered slightly to ensure your bumper doesn’t melt with the large piping. This has the added bonus of making the tips a little more visible from the rear and side of the car. In both cases, the way the upsized exhaust accents the rear of the car provides an aftermarket look, that’s classy and somehow the way it always should have been from the factory.  

CorkSport 80mm Mazda 3 Cat Back Exhaust Installed on Hatchback
CorkSport 80mm Exhaust Installed

CorkSport Quality

As with every CorkSport exhaust, this new 80mm Mazda 3 Cat Back Exhaust variant is made from fully polished T-304 stainless steel for long-lasting corrosion resistance. All flanges, hangers, and resonators are precision TIG welded in place while all of the piping is made with smooth mandrel bends. Each resonator uses a direct flow-thru design to keep the drone down and the volume up without sacrificing power.

CorkSport 80mm Mazda 3 Exhaust Hanger
CorkSport 80mm Exhaust Hanger

Power Levels

Speaking of power, check out the dyno graph below. The upsize to 80mm showed similar power gains as the 60.5mm variant, so the extra size isn’t really needed at similar to stock power levels (aside from the great noise of course!). The only change in parts or tune between the two graphs was the exhaust. OEM exhaust (red) vs. CorkSport Mazda 3 80mm Exhaust (green).

CorkSport 80mm Exhaust Power Gains
+6.6HP!

We also believe it’s also very important to be prepared. Future proofing your car for mods down the road is always a great idea, and you’ve probably heard that we have a turbo kit (yes it’s still happening!) and race header in the works. More on those projects later, but I’ll let you put 2 & 2 together…

Shop Now
Posted on

SkyActiv 2.5T: Let’s Talk Intercooler Pipe Upgrades

We recently went over the stock intercooler & piping system for the 2018+ Mazda 6 2.5T. If you missed it, be sure to check out the blog HERE.

Today, it’s the first look at the CorkSport parts that will be coming in the near future to remedy the issues we found with the OEM system. We are not covering our upgraded intercooler just yet though; today’s focus is piping upgrades!

Mazda 6 SkyActiv 2.5T engine with Intercooler Pipe

As you can see we’ve been busy getting the Mazda 6 upgraded intercooler piping designed & 3D printed for test fitting (while you can’t see it I promise the cold pipe is hanging out in there too!). I’m happy to say there’s plenty of room to fit the upgraded piping sizes that we were targeting and hopefully, they will net us a few HP gains without any other changes.

These horsepower gains typically come from removing sharp bends and diameter reductions in the stock piping that cause pressure losses. Then, the turbocharger can operate more efficiently to reach the desired boost level. Now how about some more detail on how and why each pipe has changed.

Modeling and design for FMIC piping upgrade for Mazda 6

Starting off with the hot side of things (piping from turbo to intercooler), check out the CAD image above. As you can see, the OEM piping (left) is smaller than the CorkSport Mazdsa 6 piping (right). In fact, we plan to use 2.25” piping for the hot side. Note that the plastic OEM piping is much thicker wall than the CS aluminum piping so even if the outer diameter looks similar, the inside diameter is much larger.

In addition, we keep this same inside diameter throughout while the OEM piping has a major diameter reduction through the middle. For those of you coming from a Mazdaspeed 3, 2.25” is the same size used on the hot side of all CS intercooler kits and has proven itself to support 600+WHP on Barett’s car (more info on that HERE). While we know the Sky-T may not be to that level just yet, 2.25” is a great size that gets the hot air to the intercooler as fast as possible while retaining high horsepower capabilities.

It’s not all about size though. Instead of using many tight radius direction changes like OEM, the CorkSport hot pipe uses smooth, large-radius mandrel bends throughout. This means smoother and faster airflow to your intercooler. Lastly, you may notice the CS hot pipe is significantly longer than the OEM hard plastic unit (the OEM rubber tube starts at the connection point circled in the image above). This reduces the amount of flexible connectors used, limiting what could expand at high boost levels. That being said, the CorkSport kit will use high-strength silicone with four fabric reinforcement layers to prevent any expansion anyways.

Design of piping

The cold side of the system was already a decent diameter from the factory, but as you can see, we went even larger. The rubber OEM cold pipe will be replaced with a 3” diameter aluminum pipe. This large diameter pipe and huge volume of air that comes with it right before the throttle body has proven to help throttle response and reduce boost lag on our GEN2 Mazdaspeed 3 FMIC kit. We hope to get much of the same from the SkyActiv 2.5T. The cold side also uses large radius mandrel bends for smooth and fast airflow.

Lastly, the cold side piping reduces the amount of flexible connectors used. And just like the hot side, each end of the pipe will use 4-ply reinforced silicone to prevent any expansion under high boost levels.

Those of you with a keen eye will have realized that our planned silicone connectors do not use the same connection style as the OEM intercooler. This is for good reason: we believe that the OEM intercooler will run out of cooling capacity before the OEM piping really becomes an issue. So a piping upgrade by itself wouldn’t show too much of a performance advantage.

In addition, we were able to design the piping to be the best it can without using the constraints of the OEM intercooler. So yes, the upcoming CorkSport intercooler upgrade will be required for the CS Mazda 6 piping upgrade to work, but it’s so the CS piping & FMIC combo can be the best it can be for you all!

For those of you that have stuck around this long, check out this tease of a CAD model of the CorkSport FMIC & Piping kit.

Mazda 6 Intercooler Pipe Design with FMIC

And just because we like teasing you, check this early prototype out. Testing to come soon!

Mazda 6 Intercooler Pipes

Stay tuned for more, as next time we will cover the intercooler itself. Also, let us know your thoughts down below, we love your input!

-Daniel @ CorkSport

Posted on

MZR DISI Injector Seals – The Correct Seal for YOUR Mazdaspeed

Many years ago we helped bring a revolutionary design to the Mazdaspeed community.  Fast forward 4+ years and you’ll find that the CorkSport Mazdaspeed Injector Seals are still the best option for your Mazdaspeed.  

Recently, we had a customer ship their stock block engine core to us for a fresh Dankai 2 Built Block.  During the engine core tear-down and inspection, we found a set of CorkSport Injector Seals installed.  We realized this was a great opportunity to share what we found with the community.

When the CorkSport Injector Seals arrive at your door they look like this:

Mazaspeed 3/6 Injector Seals

Brand new and fresh of the lathe with all of their beryllium copper brilliance.  After many thousands of miles of use and abuse, they look like this:

Durable Long Lasting Madaspeed Injector seals

Now to the untrained eye you may think they look bad, but the truth is they look fantastic!  The visible top of the seal has a small amount of carbon deposits present. This is to be expected because this surface is exposed to the combustion chamber.  Moving to the side of the seal you can see a distinct clean edge and no carbon deposits on the sides of the seal. This distinct clean edge is where the exterior of the seal is designed to seal in the cylinder head.  This is awesome!

Now let’s look at the inside of the used seals:

How the Injector seals look after use on Madaspeed

Again we see carbon deposits, but they are in and only in the expected locations.  Moving up the side of the seal you can see a “shelf” or “step” that is clean. This is the edge that the fuel injector seals against. Beyond that the inside of the seal is clean.

From this inspection, we can see that the injector seal was functioning as designed and doing its job effectively.  

So you might be asking…”What is so special about this design?” Well, we wrote a two-part design blog answering that exactly.  We highly suggest spending the 10 minutes to read these.

Injector Seals Design Part 1

Injector Seals Design Part 2

This is exactly why every single CorkSport Dankai Built Long Block includes a set of CS Mazdaspeed Injector Seals, but if you’re not looking for a built block but still want the assurance of the CS Seals you can check them out right here.  The install of the seal can be a bit tricky sometimes, especially getting dirty injectors out of the cylinder head.  Because of that we’ve developed an injector puller tool that makes the job MUCH easier.  

We hope you enjoyed this quick tech inspection of the injector seals!  Thanks for tuning in with CorkSport Mazda Performance.

Stay up-to-date on the latest news and product updates from CorkSport.

* indicates required