2018+ Mazda 6 2.5T OEM Intercooler & Piping Analysis

We’ve already mentioned briefly that we have an upgraded intercooler kit in the works for the SkyActiv 2.5T, but now it’s officially time to dive in and get into how and why an upgraded intercooler kit is a good fit for your 6. To understand how to make a performance part, we first have to understand what makes the stock parts tick and where we can improve them, which is what we will be covering today!

For those of you that are new to the boosted lifestyle, I feel that I should go over a few terms that will be thrown around frequently later in this blog.

  • Hot Side Piping: Also known as just “hot side” or “hot pipes” this piping section carries the pressurized air (boost!) from the turbocharger to the intercooler. As it is before the intercooler, the air has not been cooled and the “hot” name is quite accurate (think 200-250°F. or even more on a turbo that’s too small). Shown above on the right side.

  • Intercooler: A basic heat exchanger. Air flows through the inside and is cooled by air flowing through the outside while you drive down the road. The same way a radiator works except with air inside instead of coolant. It is made up of three parts the “end tanks” and the “core”. The end tanks are what transfer the air from the piping to the core while the core is the actual heat exchanging portion. Shown front and center in the above image.

  • Cold Side Piping: Also known as just “cold side” or “cold pipes” this piping section carries the pressurized air from the intercooler to the engine. As it is after the intercooler, the air has been cooled to make more power. Shown above on the left side.

 

Now into the details…

The hot side piping must make its way all the way from the rear of the engine to the front of the car. The OEM piping takes a pretty direct route, and is a decent diameter for stock piping, starting & finishing at just under 2” inner diameter. This, however, is where the good things end.

To start, the two rubber sections of the hot side are single ply. These allow for good flexibility on install and to allow for engine movement but will start to expand on higher than stock boost levels, increasing boost lag and decreasing throttle response. In the image above, the main rubber section squishes under the small weight of the upper plastic section of the hot pipe. This isn’t even the main issue with the hot side piping!

The upper plastic section of the hot side has quite a few small radius bends, and a few areas where the pipe reduces in diameter severely, affecting the maximum flow and restricting the power of your 2.5T. Check out the worst area below, it’s tiny!

And what might be causing this reduction in diameter you may ask?

That’s right, its clearance for a hose clamp. Mazda, I’ve got to call you out on this one, couldn’t you have just rotated the clamp, and kept the diameter in the pipe? Anyways, on to the intercooler itself.

The intercooler itself isn’t too bad, a decent sized core with lots of fins to help cool as good as it can. That being said, there’s still plenty of room for improvements. First: make it bigger. The intercooler mounting could’ve been simplified to get more width, and there’s a bunch of room to go thicker. While thick is not the best for heat transfer efficiency, it will still help cool off the air better. Height is already more or less maxed out without cutting up the crash beam, but we should be able to make enough extra volume elsewhere to make a big difference.

Intercoolers are a delicate balancing act between cooling efficiency and pressure drop. Cores that cool extremely well usually have a larger pressure drop (loss of pressure from inlet to outlet) and vice versa. With the high fin density of the OEM intercooler, we can expect a relatively high-pressure drop (2-4psi would be my rough guess) but pretty good cooling. From early dyno testing on the CorkSport Short Ram Intake, the intercooler does a good job cooling but loses power on back to back dyno runs. I expect that this is the intercooler “heat soaking”. Heatsoak is what happens when an intercooler is undersized or is not getting enough airflow, it heats up and is no longer able to cool the boost off, robbing you of power.

The two images above show the real Achilles heel of the OEM intercooler and what is likely causing the heatsoak issues: the end tank design. Since the charge air enters and exits the core at an upward angle, it’s being directed away from the lower runners of the core. There is a sharp angle that would be hard for the air to turn, meaning the bottom three internal runners (shown with the red box) are likely not actually doing much. So you’ve got intercooler taking up space that is likely not doing much… We aim to fix this.

The cold side of the system is actually pretty good-inner diameter of just under 2.25” on the ends (even larger in the middle) and a short path into the throttle body. We’ve already covered the basics of it when discussing the upcoming CorkSport boost tube HERE. Like with the hot side, the rubber connector is prone to expansion under increased boost levels. While the CorkSport silicone boost tube will still be coming on its own, we plan to offer something even stiffer that is optimized for our upgraded FMIC kit.

Much more information to come in following blogs as we’ve been busy working away on this project. Stay tuned for full details on the upcoming CorkSport FMIC kit, and if you’ve got any questions, leave them down below.

-Daniel @ CorkSport

Mazda 6 Turbo and CX-9 Short Ram Intake

That’s right, it’s time to start making more power on the SkyActiv 2.5T. We are proud to introduce the CorkSport Power Series Short Ram Intake for 2018+ Mazda 6 equipped with the 2.5 Turbo Engine and 2016+ Mazda CX-9 . We replaced the restrictive factory airbox with a free-flowing intake system that was designed to help your turbo breathe significantly better. The SRI offers better performance, sound, and looks in an easy to install package. Read on for full details, and be sure not to miss the sound clips in the video below!

This CorkSport Short Ram Intake was designed specifically to get the best the 2018+ Mazda 6 2.5T and 2016+ Mazda CX9 has to offer. From the precision machined MAF housing to the high flowing filter, each component in the CS system offers an improvement over the stock counterpart while retaining great fit and finish. All mounting hardware, brackets, and clamps are included to make your install quick and painless.

Starting at the OEM turbo inlet pipe, the factory airbox utilizes a ribbed and flexible rubber elbow. While working well enough, the ribs induce significant turbulence into the intake tract. The CorkSport intake replaces this elbow with a smooth flowing silicone elbow. In addition, the silicone is 4-ply reinforced with nylon to eliminate any chance for volume reduction under wide open throttle.

Next comes the MAF sensor housing. The MAF sensor essentially reads the volume air that is entering the engine so the ECU can adjust tuning to suit. Since the OEM unit does a good job here, it was imperative that the CS MAF housing matches to ensure no check engine lights or tuning issues. The CorkSport MAF housing is precision machined from 6061-T6 billet aluminum to match the OEM housing to ensure no CELs, no tuning issues, and great flow.

Finally, the CS SRI uses a performance AEM dry-flow filter. A high-quality filter like this is long-lasting, reliable, and can be washed and reused. It has superior filtration to the OEM filter, while also allowing more airflow into the intake tract.

Now for what you’re all really interested in: power gains. By removing the restrictive OEM airbox and turbulent intake elbow, we were able to pick up 8-12WHP from ~4000RPM out to redline. This power bump comes with no tuning changes and with identical testing conditions. Check out the dyno graph below to see for yourself! Note: the variance in low RPM (2800 and lower) is due to difficulties associated with dyno testing an automatic vehicle.

Freeing up a few extra ponies is great but what you will really notice is the added engine and turbocharger noise. That restrictive airbox does a little bit too good of a job at dampening out all the fun sounds that come with a turbo. We were honestly a little surprised by the flutters, whooshes, and psshh noises that come with the CorkSport SRI. You also gain a little extra engine induction noise under hard acceleration. The extra noise is enough to be fun when you want it but not annoying or distracting when you don’t. Watch the video below to see what it sounds like.

As with most CorkSport products, this SRI kit comes with all the clamps, hardware, and even a support bracket for the MAF housing to ensure you have an easy and quick install.

The CorkSport SRI for 2018+ MZ6 2.5T & 2016+ CX-9is a great modification whether it’s your first or the just the latest on a long list of builds. It provides a noticeable power gain, adds some extra fun to your ride, and will support future mods down the road. Pick up yours today!

Be sure to contact us with any questions you may have, we will be happy to help!

Mazda’s Dynamic Pressure Turbo – A Closer Look

There has been a lot of buzz about the new(ish) turbocharged SkyActiv-G 2.5L first found in the Mazda CX-9 and now in the Mazda 6.  Along with all this buzz, there are a lot of unknowns as well. Here at CorkSport, we’ve taken the step to try and address some of these unknowns.  What is Mazda’s “Dynamic Pressure Turbo” and how does it work? There have been diagrams bouncing around on the internet, but no close-up view of the turbocharger itself.  That’s about to change.

If you haven’t already read Daniel’s first installment, “Mazda Dynamic PressureTurbo an Introduction.” You wouldn’t want to miss out on the extra information before reading on.

The turbocharger found in the 2.5T equipped CX-9 and 6 is quite complex in design.  There are many aspects to the OE turbocharger we could discuss, but today we are going to focus solely on the dynamic pressure system and turbine housing.  

If you are reading this, then you’ve probably already seen various diagrams depicting how the dynamic pressure system works and showing Mazda’s clever 3-2-1 exhaust port design.  If you haven’t, check it out below.  Image credit to Car And Driver Magazine for the fantastic diagram.  

Mazda’s 3-2-1 exhaust port design takes full advantage of the engine cylinder firing order.  The advantage is improved exhaust gas scavenging for the adjacent cylinder (more or less the cylinder that just fired helps pull the exhaust gases out of the next cylinder that is about to fire).  Ok moving on; this is great, but how does the dynamic pressure system come into the mix?

Shown here are the turbocharger assembly and the dynamic pressure valve assembled as one unit (the first two images also showed the fully assembled setup).  The three ports are clearly visible along with the “vane” that passes through the three ports. This vane rotates depending on engine RPM to control the exhaust gas velocity entering the turbine housing.  The vane itself is controlled by the larger blue colored actuator.

Now let’s take an even closer look.  The vane does not open until approximately 1600rpm, but the engine could not run of no exhaust gas can flow out of the engine.  To resolve this Mazda has designed the dynamic pressure system with two exhaust gas paths.  Looking at the above image you can see a small opening just above the vane. This is the sub-1600rpm exhaust gas path.  

By reducing the cross-sectional area of the exhaust gas path, the exhaust is forced to accelerate through the dynamic pressure system and into the turbine wheel.  This effectively reduces turbo lag, improving the vehicle’s response at low engine RPM. Once the engine revs past 1600rpm the vane opens, allowing the larger path to be used.   

Here we show the turbocharger assembly (right) and the dynamic pressure valve assembly (left) separated.  Looking at the dynamic pressure valve assembly, you can now more clearly see the three small paths above the larger path with the vane inside.  Then look at the turbocharger assembly and you will see the small upper path and the larger lower path.

The fact that these two assemblies are separate systems is great news for the enthusiast.  The development of a performance turbocharger will be much more feasible and the dynamic pressure valve can be retained with the performance turbocharger.  One more detail to point out.

Mazda put a lot of thought into the design of the wastegate port; let me show you why.  First, looking at the inlet of the turbine housing you can see a small vertical wall in the large path.  This wall creates a completely separate path to the wastegate port which is very unusual on an OE turbocharger. Combine this design with a very large wastegate port and you get a design that can “waste” or divert an excessive amount of exhaust gas.

This tells us the SkyActiv-G 2.5L engine is creating a lot of (currently) unused exhaust gas energy.  Again this supports the feasibility of a performance turbocharger suiting Mazda’s new turbo engine quite well.  

Great things are on the horizon for the 6, now if only Mazda would put this engine in the 3 paired with a 6-speed manual transmission.  Oh, one can dream.

-Barett @ CS

All About That CatBack Exhaust

Mazda Catback Exhaust Installed

Ever wondered the key factors of making a decision about your aftermarket exhaust? Why Cat-back? 

Is it the diameter of the exhaust that says performance? Or is it the type of metal used? What about fitment to your current setup? None of these questions by themselves answer what you need by themselves, but all of them together help when making the decision on how to get more power out of your Mazda.

At CorkSport, we have made it our #1 priority to make our customers dreams a reality. Whether you drive a Mazdaspeed or a regular Mazda, we’ve made sure to engineer a great fitting exhaust that maximizes engine performance.

Check out the Cat-Back Exhausts by Car Model Below:

Take the Mazdaspeed 3 for example: When you purchase a CorkSport Catback Exhaust, you’re getting T304 stainless steel piping that has been polished to a mirror-like finish.

You’re also getting true 80mm piping, which is slightly bigger than three inches, making our exhaust one of the biggest bolt on catback systems.

Fitment is also a big concern to us. We make sure our exhaust systems are mandrel bent and TIG welded to make a perfect bolt-on fitment.

Mazda 6 Power Series Exhaust

Now that you know our exhaust is 80mm piping, polished to perfection, and made to be a direct fitment, you can bet this exhaust will increase performance and sound. By installing our cat-back exhaust, you’re removing the secondary unmonitored catalyst making the exhaust flow much faster out of the motor. By increasing the velocity of exhaust gases out of the motor, you increase power and make your turbo spool up a little bit faster.

Among the power gains you’ll see from installing the CorkSport Catback Exhaust, you’ll also have a car with a deep growl to it. Our exhaust has one of the best sounding tones on the market. With a quality made exhaust, comes quality sound.

When find yourself ready for a cat-back exhaust, be sure to check out CorkSport to ensure you get the highest quality for your ride.

 

2018 Mazda 6 Performance Parts – Cold Side Boost Tube

You have probably heard us mention the new Turbocharger Mazda 6 in the recent weeks and months and have probably been wondering; “what’s going on?”  Well, today we’d like to share a little bit about what’s been going on at CorkSport HQ with our very own 2018 Mazda 6.

Right off the bat, I can say we have a handful of exciting performance products in the works and will be sharing info on them as we make progress.  Today we want to talk about the intercooler piping, specifically the cold side piping and the parts of the system. This is the piping that connects the outlet of the intercooler and the throttle body.  It is commonly referenced as the “cold side piping” because the charge (boosted) air has passed through the intercooler and is therefore cooler.

The OE cold side piping consists of three main components.  Starting on the right side of the image; we have the hard piping that connects to the intercooler and a soft rubber hose.  Next is the soft rubber hose itself, which we will talk more about later. Lastly is the throttle body connection, which is the oddest part of this system.  You can see why in the next image.

The above-mentioned intercooler hard pipe and the rubber hose are pretty common parts on modern turbocharged vehicles, but the throttle body connection is unusual from our experience.  The throttle body connection appears to be designed for a quick connection (and not so quick disconnection) during the vehicle assembly process. Unfortunately, this leaves a very odd connection flange on the throttle body itself.  Lastly are the fins inside the connection part; other than straightening the airflow entering the throttle body we don’t see many purposes these. We will be testing the effects and need for these in the near future.

Now let’s get to what we really wanted to talk about; BIG Silicone Performance Parts.

Mazda designed the Turbocharged 2.5L SkyActiv-G to function at a specified boost pressure and no more.  However, we fully intend to change this set boost pressure for increased smiles per gallon. With increased boost pressure comes more force and strain on the OE rubber hose.  Eventually, the OE rubber hose becomes too flimsy for the increased boost pressure and may expand or fail completely via a rupture.

So how do we develop a performance part to replace a rubber hose?  Well, there is one obvious improvement and another not-so-obvious change that can be made.  First, we use silicone as the prominent material for its excellent heat resistance and durability.  Next, the silicone is reinforced with five layers of fabric braiding to withstand the increased boost pressures.  Compare this to the OE single layer of reinforcement and you can see why this would make a big difference.

Now for the less obvious performance improvement; the CorkSport 3D Printed prototype is larger in diameter than the OE rubber hose.  Leaning on our experience with past intercooler piping development, we have found that increasing the charge air volume directly in front of the throttle body increases throttle response and helps spool the turbo faster, reducing turbo lag.  

Currently, we are still in the development phase but will be testing soon.  Stay tuned for future updates on the CorkSport Performance Boost Tube and other exciting products for your 2018 Mazda 6.  

-Barett @ CS