Getting accurate readings for your Mazda Skyactiv 2.5L turbo is nearly impossible. Now your boost & vacuum signal for your 4th generation 2021+ Mazda 3 turbo just got so much easier with the CorkSport Boost Reference Adapter. Designed for all Skyactiv 2.5L Turbo models, adding a boost gauge could not be easier!
Mazda, We Have A Problem
While we are all grateful that Mazda finally put a turbo in the 4th GEN Mazda 3, they did not see fit to include a boost gauge of any type for the driver. Adding a boost gauge to your Mazda 3 Turbo (or other Mazda models with the 2.5L turbo engine) is now easy with the CorkSport Boost Reference Adapter & CorkSport Boost Gauge!
The Challenge
The challenge with Mazda’s design is that they didn’t provide a port to get boost and vacuum signal from your Skyactiv Turbocharged engine. Why?! It’s a mystery to us. Since data is crucial to improving performance, we wanted a solution to get this information. It quickly became apparent to our engineers that we needed a bolt-on solution that provides the world with the missing link!
A Bolt On Solution
The CorkSport Boost Reference Block provides a very simple way to source boost and vacuum from the intake manifold post intercooler. This gives you the best possible boost signal right as the airflow enters the engine.
The installation is easy. The bolt-on design allows you to simply attach your boost gauge hose to the barb fitting once the adapter block is installed! Boom! Now that the problem has also been solved, let’s build a better Mazda 3 Turbo!
2024 looks to be freaking fantastic for the Mazda 3 Turbo performance enthusiast, and here’s why. CorkSport has been diligently developing a Drop-in Performance Turbo Upgrade for the SkyActiv-G 2.5L Turbo engine alongside the dozens of Mazda 3 performance parts we have released to the community.
With recent rumblings of a reworked OEM turbo option circulating through social media, we thought it was time to officially share the R&D we have been quietly working on.
As you can see, we have a 100% complete and new design in the 3D CAD model above. We are developing a performance turbo upgrade from scratch with larger and performance-optimized housings, CHRA, and wheels, all designed to work together.
Choosing this design path takes a lot more time, effort, and money to create a finished product. Despite the increased resource requirements, this is what it takes to develop an efficient and reliable performance drop-in turbo for the Mazda community. Now, let’s apply some context to that statement.
Back in 2018, we wrote a couple of blogs dissecting the OEM turbo found on the Mazda 6 2.5T. At that time the Mazda 3 did not have a turbo option yet.
We inspected the housings, wheels, CHRA, and Mazda’s “Dynamic Pressure” system. We quickly realized that the OEM turbo would be a HUGE limitation on the Mazda Turbo engine’s performance – even once tuning was fully available. Fast forward to the announcement of the Mazda 3 Turbo option, and we got to work on an improved turbo design.
Hybrid Compressor Wheel (left) 50.4mm Inducer & 63.3mm Exducer with extended tip vs OEM ~43mm Inducer & ~56mm Exducer
One of the first steps we took was building a “hybrid” OEM turbo to see how that would perform vs the OEM turbo. A hybrid turbo means an OEM turbo that has been modified to use larger than OEM wheels. Above you can see the larger compressor and turbine wheels next to the OEM wheels.
Our testing showed some potential with a “hybrid” setup turbo, but there were still limitations to the power potential. We saw a bit slower spool and a bit more mid-range power potential, but top-end power was still struggling to hold. Granted this was very early in the tuning developments for the platform.
A major concern we had was around the hybrid turbo, was the reliability and further cracking of the OEM housing once it was modified for the larger wheels. The OEM turbine housing is very small, specifically the turbine scroll which is the most critical part of the turbine housing. The OEM housing just didn’t have a lot of extra material to work with (remove) to safely accommodate a larger turbine wheel.
Check out this image of the turbine housing after it was machined to accept the larger turbine wheel. The thin edge marked by the blue arrows is very thin due to removing so much material. This area of the turbine funnels the exhaust gases into the turbine wheel inducer and directly affects the efficiency of the wheel. Had we machined any more material for a larger wheel, we would have started to affect how the exhaust gases enter the turbine wheel.
In the image above, the inlet divider inside the turbine housing is cracking. In the image below, an internal portion of the scroll is cracking as seen through the wastegate port.
We’ve already seen OEM housings cracking from normal use, so the idea of thinning the turbine housing in critical areas did not seem like the right approach for a performance turbo upgrade.
A hybrid turbo may have a place in the performance aftermarket and it may have some performance benefits (if the housing is up to the task), but if we are going to stand behind the product; we are going to develop it from the ground up to proactively eliminate reliability concerns.
So that’s exactly what we are doing!
Our Development Expertise
Leaning on our development expertise with the CST Turbo line for the Mazdaspeed platform, we are designing a new turbo from scratch for the Mazda 3 Turbo and other models that share the same engine.
Starting from the ground up gives us the ability to optimize the turbo for performance applications. Like the Mazdaspeed CST Turbo line, we can directly control the size of the housings, CHRA, wheels, wastegate, material thickness, and material type.
Designing the Mazda 3 Turbo
Now let’s dive into the design of the housings for the upcoming Mazda 3 Turbo upgrade. Starting with the compressor housing; A LOT is going on with the compressor housing design. We call this a feature-rich part and you can see why below.
The OEM compressor housing (right) has a handful of integrated features: the obvious compressor inlet and outlets, the electronic wastegate mounting, the electronic bypass valve, and the EVAP/Breather port. When designing a performance drop-in turbo, our goal is to retain all these OEM features so that installation and use are very simple and easy.
Alongside the OEM features are the changes we have made to increase performance potential which includes a slightly larger scroll A/R of 0.60. Note: This even exceeds our CST Turbos and has been proven to be responsive and support a flow of 700whp.
Here you can see the blue lines showing the larger compressor scroll. CorkSport is on the left and OEM is on the right. Increasing the size of the scroll A/R helps improve the compressor wheel efficiency and max flow capacity. Along with a larger scroll, we have also designed the housing to have either a stock-size inlet or a 3.5” anti-surge inlet for the larger turbo option.
Yup…there’s going to be more than one size available. More on that later…
To do this we have to move some things around, but don’t you worry every part of this development is verified on a car with 3D printed prototypes and then functional prototypes. This is a critical part of the development to make sure everything fits like OEM but punches like the hot hatch we all asked Mazda for.
A Larger Responsive Turbo
Now let’s check out the party side of the turbo…the turbine housing. In my personal opinion, turbines make power and compressors just support the required flow. So what are we doing on the turbine side of things to make more power?
Several changes have been applied on the turbine side to increase performance and reliability. Here are the CorkSport (left) and OEM (right) turbine housings next to each other.
Our goal is to develop a turbo that is fun, responsive, and carries power like you would expect. Referencing the blue lines you can see a drastic difference in the size of the turbine housing scroll. While the CS design is a large increase in size over OEM, it is not “bigger” than a typical aftermarket generic fitment turbo – highlighting just how tiny and limiting the OEM turbine housing really is.
Now let’s take a look inside the housing so you can understand what is changing.
An Improved Design
Both turbines (CS & OEM) are single scroll designs, but you will notice two major differences.
Firstly, the spiral section of the CS design is drastically larger than OEM; this is the true “scroll” of the housing and thus the section of the housing that funnels the exhaust gas into the turbine wheel. We changed two aspects of the scroll design:
The “swallowing capacity” of the scroll has been increased so that the peak flow capacity of the turbine is much greater than OEM. This is the cross-sectional area at the beginning of the scroll shown by the blue arrow.
The scroll A/R (Area/Radius) has been increased from 0.53 to 0.71. This ratio number affects how “quickly” the exhaust gas is forced into the turbine wheel. The smaller ratio is a faster spool but poor top-end power and a larger is slower spool but more top-end power. The goal here is to find the right balance of spool/response and top-end power.
Second, you may have noticed the CS turbo is missing the red blocky section that the OEM turbo has. It’s missing for good reason.
In the above image, you can see the OEM turbo with the turbo on the right and the dynamic pressure valve on the left. Mazda uses this control valve to help spool the turbo below 2000 RPM and it seems to do the job, but it has cracking issues from what we’ve seen and is going to be a huge flow restriction on higher power setups.
We are getting rid of it!
The Pursuit of Reliable Performance
In the pursuit of performance and reliability, the dynamic valve and its housing had to go. Like the OEM turbine housing, we’ve seen cracks forming in the dynamic valve housings so we know they are a reliability issues and Mazda knows as well.
Mazda is also getting rid of the dynamic valve system…the CX50 Turbo has a much simpler twin-scroll turbo design with no dynamic valve and I assume that change will find its way into all 2.5T models sooner, rather than later.
To keep things as simple as possible for you, the enthusiast, the CorkSport-designed turbine housing mounts directly to the cylinder head and still takes advantage of Mazda’s trick 4-3-1 exhaust port design. Along with that change, the OEM EGR port is retained and new heat shields will be part of the kit.
That covers the housings for the upcoming CorkSport Drop-In Turbo Upgrade for the Mazda 3 Turbo. We are excited about this project and even more excited to bring this to the community. Who doesn’t love boost right?
Expect to hear more as we roll further into 2024 and until then enjoy these teaser shots of the raw castings.
Based on popular demand, we have developed a filter sock that will help fight dust and water spray from entering the engine. The CorkSport Mazda Air Filter Cover mod can help maintain the flow efficiency of your main filter and extend its service life.
Quality Materials
The Air Filter Cover is made from a polyamide fabric mesh and allows for good airflow while adding a layer of protection for your air filter and engine. The cover protects against dust, large debris, and light water spray from entering the filter media.
The small air filter sock works on 3.0, 3.5, & 4.0 marked air filters only
The large air filter sock works on the 4.5 marked air filter only
You can check your CorkSport air filter here:
If you don’t have a CorkSport specific intake, there is still a good chance your Mazda can enjoy the benefits of our air filter sock. Follow the diagram below to see if your air filter size matches:
Air Filter Sizes 3.0″, 3.5″, 4.0″
With fall upon us and winter just around the corner, now is the best time to add an extra layer of protection to your Mazda! Thanks for checking out the new air filter sock cover for your Mazda intake system.
Do you need to replace your swaybar end links and want an upgrade at the same time or are looking to adjust your sway bar to better match the factory position on your lowered car? That’s where the Performance Adjustable End Links come in and they are now available for the following models: 2019+ Mazda 3, 2014-2018 Mazda 3, 2021+ CX-30, 2022+ CX-50, 2014+ Mazda 6, 2013+ CX-5, 2016+ CX-9, and 2006-2007 Mazdaspeed 6. Depending on your specific application, both front and rear end links are available. The new CS Adjustable End Links build off of the wildly popular kit available for the Mazdaspeed 3 and carry over all the same benefits which are discussed below.
Why You Need End Links
Getting straight to the main advantage of the CS end links is their variable length. The CS end links offer ~18mm or 0.70in of adjustability. This results in an end link that can be up to 9mm longer or 9mm shorter when compared to the stock part.
If your car is lowered, our end links allow you to account for the change in sway bar position that occurs when you lower your car so it can be placed closer to its original position. When the sway bar is not positioned in the OE location it can lead to sway bar preload or binding which can have negative effects on handling. This also means that if you are planning on adding a lift they can help in the same way.
Quality Matters
The construction of the end links also maintains the same high quality as found in the current end links for the MazdaSpeed 3. The center section is CNC machined out of 2011-T3 5/8in hex aluminum to provide a large increase in size over the OE part while being easily adjusted to your specified length with a wrench. After machining, the center section then gets anodized in black to provide a finish that will help protect it from corrosion.
The included ball joints feature a sealed design to reduce the chance of water or other foreign material from gaining access to the joint. This allows the ball joint to provide a longer service life so that it won’t require any additional maintenance compared to the OE end links.
With the long new list of applications, you should have no problem finding a set of CS adjustable end links that will fit your Mazda. Be sure to head over to the product listing for your specific model for more info and pictures. As always, reach out if you have any questions about the end links for your setup.
Let’s talk Oil Catch Cans! While not the most exciting performance part for your turbo Mazda 3; when properly applied they can be a keystone to improving the health and longevity of your engine’s life. With that being said, they are worth a discussion in more detail about why an oil catch can (OCC) is needed and what the benefits are. As with any performance modification, there are many different ways to achieve the end goal, but not all are created equal.
Let’s break down the CorkSport Oil Catch Can system so you can learn and understand why we utilize an OCC the way we do. While we did break this down a bit back in 2019 here, we want to take it a step further now.
Improving the System
First, let’s provide you with some context. What is the system on the car/engine that the OCC Kit is working to improve? All modern engines utilize a Pressure Control Ventilation (PCV) system to regulate and control the internal pressure of the crankcase. This is not to be confused with the pressure inside the combustion chamber.
As you can see in the image above, there are two major components of the PCV system on the engine. Typically there is a breather vent integrated into the valve cover that will vent/route directly into the intake system. On turbocharged engines this vents upstream of the turbocharger compressor inlet.
The second part is a “cover” on the front side of the engine block typically hidden under the intake manifold. This cover has built-in baffles/chambers and a PCV valve. The PCV valve is a basic one-way check valve that allows pressure to flow out of the engine crankcase and into the intake manifold directly.
Left Side: Here is an example of a SkyActiv-G 2.5L PCV Cover with the PCV Valve at the top.
Right Side: Here is an example of the baffling on the engine block inside the PCV Cover.
The Goal
So what’s the point/goal of the PCV system? Two main reasons:
Reducing the pressure buildup inside the engine crankcase. This improves the durability/longevity of the engine and improves engine efficiency.
Emissions control. The pressure buildup inside the crankcase comes from the combustion process in the cylinders. The rings on the pistons do not have a perfect seal, thus some combustion gasses and fuel are able to push past the piston rings and into the crankcase. This is called “blow by”. This blow by and fuel getting past the piston rings worsens during cold start and eventually results in dilution of the engine oil due to the excess fuel.
We invite you to check out the Engineering Explained video about this specific topic. He does a great job explaining and showing this exact system and issues with it. https://youtu.be/uVd-ZS5bnyY?t=337
Here you can see the captured fuel and water vapors of a CorkSport OCC installed for ~3000 miles on a 2018 Mazda 6 2.5T. This engine only had 500 miles at the time and had an average commute of 15 miles & 20 minutes of mixed traffic and speeds.
Had there not been an OCC installed, this vapor would have been directly ingested into the intake system at the turbo compressor inlet and the intake manifold. Over enough time, this builds up on the surfaces of the intake system, turbocharger, intercooler system and intake valves…diminishing performance and fuel economy.
Sadly, while Gasoline Direct Injection (GDI) technology has provided some exceptional improvements in power and fuel economy, there are still negatives to the overall system. Dirty intake valves and fuel dilution are the main concerns.
Here is an example of direct intake valves…
Now let’s talk about what makes the CorkSport OCC System unique vs the current options available.
It’s a complete system, not a half system. Meaning the CorkSport OCC incorporates the valve cover breather AND the PCV cover on the front of the block.
Dual Chamber Design: this separates the incoming vapor from the valve cover and PCV cover to the lower chamber to condense and be drained later. The air then passes through a baffle to the upper chamber and then exits to the intake system.
Constant Vacuum: Due to the design, the CS OCC has a constant vacuum pulling pressure and vapor from the crankcase. This is important to note because with the OEM system, the PCV Cover and valve close while in boost…which is when most blow by is happening. With the CS design, you are pulling more vacuum through the OCC while in boost.
Low Mounting: While this seems trivial it’s important from a physics standpoint. The fuel in the oil turns into vapor once the engine and oil are up to temperature. Then the OCC can draw the vapor out of the engine. Once this happens the vapor will start to condense back into a liquid; most of it will make it to the OCC itself but some will condense in the hose. We want the hose to drain into the OCC, not the engine.
Here you can see the general routing of the CorkSport oil catch can over a CX50 engine bay (routing is the same for all turbo 2.5L SkyG models). The red lines are the routing from the valve cover breather and the PCV. They “T” together and then enter the lower chamber of the OCC. The blue line is the clean air exiting the OCC and being drawn into the intake system just before the turbo compressor inlet.
Let’s wrap this up! GDI Tech is great but has some issues. In factory form, the OEM PCV system works but could be better…enter the CorkSport Oil Catch Can Kit.
By changing the routing and adding a proper tank to catch the oil, fuel, water vapors that collect inside the engine you are effectively helping your engine breathe better. Reducing the amount of particulates and vapor entering the intake system reduces the overall build-up on the intake valves and other various components.
With the optional drain valve system, you can easily service the OCC when you perform you regular oil changes. While not sexy, it is essential and your Mazda will love you for it.
We hope you have enjoyed this tech blog and we hope it has helped you learn more about your beloved Mazda. Check out the Oil Catch Can for more details and to get yours today!
