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

3rd Time’s the Charm

We all know the saying the 3rd time is the charm and this year’s SCCA National Championship Runoffs was no exception to the rule.  The past 2 runoffs I have not made it to the finish.  In 2016 at Mid-O I was hit on the first lap and punctured my left front tire.  At Indy, I retired as we developed a fault in the ECU from some beta software we were running and the car dropped into limp mode and I wasn’t able to maintain full throttle.  

We have been working on the brakes for the past 3 years and during the season it limited us from running the car as much as we like.  We have also been chasing a fault/error with the ECU/control system of the car. We were still able to get the car enough starts and race finishes to get qualified for the runoffs in Sonoma.   Granted the car was not happy at most of those races and it was a struggle to get the finish.

2 weeks before the runoffs we sorted out the ECU problem and were confident enough in the car to race it.  The backup plan was to race my Spec Miata if we couldn’t get the Mazda 3 fixed as I ran it this past season as well and had enough starts/races.

With the Runoffs at Sonoma it was within 1-day driving distance unlike the past 3 runoffs at Daytona, Mid Ohio, and Indy so I got to try out the new (to me) truck and trailer.

I had raced at Sonoma one time prior, so the track wasn’t totally unknown like Mid-O and Indy, which all I had was simulator time so I was able to get up to speed quickly on a test day and find out what I needed to work on for chassis setup and driving.  The driving was easy to adjust, look at the data, see where the driver was sucking and had to man up to keep a foot to the floor in some sketchy corners.

The car, on the other hand, had what we call “a good problem to have”, too much power.  We have been running a torsen style differential in the car which works pretty good in a straight line and relatively flat tracks.  Sonoma is not a flat track which unloads the car 3-4 times per lap. With the Mazda 3 and the amount of torque it makes means I was unloading the tire enough for it to spin the inside tire.  Most people think what is the big deal with a little tire wheel spin? It is a problem when you enter turn 10 at Sonoma at 97MPH and you start lighting off your right front tire. Look at the picture below and you can see that front inside tires is barely on the ground and the rear isn’t.  The speedometer would jump around and you could see the right front wheel speed turning at 5-10 mph more in the data.

We tried several suspension changes and driving style changes to make the best of it but in the end, we were way off the pace by 2-3 seconds of the rear wheel drive cars in the class.

The good part about not being at the front of the field, there was zero stress when race day came.

Like any race there was a fun challenge, we would be heading into turn 2 blind as the race was at 4 pm in the afternoon and the sun would be shining directly down the hill.  Since I wanted to see the end of the race I a little cautious at the start and Ali in the other Mazda 3 got around me at the start.

We fought it out for 8 laps and he went into turn 6 too hot and I was able to get under him and pass him on the inside.

After a few laps I put a 4-5 second lead on Ali I was basically in no man’s land, slower than the front guys and faster than the back half of the field so I spent my time working on tire management (it is easy to overheat your left front tire at Sonoma) and made it to the end of the race.

My official finishing place was 10th but after some adventures in tech, I was moved to 9th in the final results.  This isn’t where I wanted to be by any means but the 3rd time was the charm and I made it to the end of the race.

Huge thanks to the support we get racing the car from CorkSport, BFGRacing, Monarch Inspections, G-Loc Brakes, and Mazda Motorsports.

 

Derrick Ambrose

Exhaust Scavenging

In this blog, we are going to SHOW a demonstration of exhaust gas scavenging.  Instead of a lengthy blog full of text, we’ve opted to create a video that demonstrates the effects of exhaust gas scavenging for both good and bad designs.  

We will be comparing the prototype CorkSport performance exhaust manifold, developed for the Mazdaspeed 3 and 6, to the OE exhaust manifold.  

Exhaust gas scavenging within a manifold is the process of one cylinder runner, pulling (aka scavenging), the exhaust gas from an adjacent cylinder in a continual cycle.  Now enough talk, to see an awesome example and an awful example of exhaust gas scavenging check out the video below. BONUS! Not only do you get to see what optimal scavenging looks like, but this is also the first sneak peek of the CorkSport Performance Exhaust Manifold…

Video Link: https://youtu.be/RtydboDbwpQ

We hope you found this as interesting as we did!  Stay tuned as we continue developing the CorkSport Performance Exhaust Manifold for the Mazdaspeed platform.

 

-Barett @ CS

Safely Upgrade Your Mazdaspeed Turbo

It doesn’t take long for those building power to use up the stock K04. They are prone to fail, especially when you start shoving that extra air through it. A common question is, “My Mazdaspeed is smoking, is my turbo bad?”

First things first. There is a BIG difference between replacing a bad turbo and upgrading to a more efficient one for more power. If you want to replace it, go with OEM and just plug and play, you’re good to go, wash your hands and get on with your life. This will have your car up and running pretty quickly. However, your maximum power output will be limited and you will eventually have the same problem – the KO4 will fail.

If you are saying to yourself, “It’s time to upgrade…I NEED more power in my life!” Then this blog is for you. Below, we lay out the basics needed to successfully install a CorkSport Mazdaspeed Turbo, highlighting the required supporting modifications to keep your Mazdaspeed safe. And as an added bonus, we keep our installation instructions on each of our product pages, so you can preview how easy the install will be for your experience level.

Here it is, the list is comprised of the BARE essentials to run the 18G CorkSport turbo.

 

HPFP INTERNALS

Giving you 50% more efficiency with your fueling system, as well as, a strong base to build power for your Mazdaspeed. The CorkSport Max Flow Fuel Pump Internals are built to directly replace your stock fuel pump internals and perform with immediate improvements.

CorkSport fuel pump vs. competitors

ACCESSPORT (or VERSATUNE if you have a CX-7)

The Cobb Accessport will give you the basis for tuning, and since this is required with the CorkSport turbo – you’ll want to make sure you have this in hand and ready for when you install your turbo.

These are the basic foundation to our Mazdaspeeds, without these two items you cannot operate your Mazda after installing an upgraded turbo.  You will need your Mazdaspeed tuned, and your tuner is going to say the same thing.

That’s it, that’s all you need to run the CorkSport Mazdaspeed turbo safely. With this proper foundation, you can put yourself in a position for efficiency, or more power.

Now the question is do you want to make it go fast and harness the power that this turbo is built for? Keep reading and we’ll provide some other awesome upgrades that are the next step once you have your turbo installed and running.  Oh, and if you are looking for a proven path to make 400WHP, check out our Chasing 400 WHP Blog here!

CorkSport Upgraded 3.5” Intake

The CorkSport turbo is rated for up to 450WHP with the right set up. Unless you are going for the MOON and shooting for over 700WHP a 3.5” intake will be more than sufficient for this turbo. Giving you some extra airflow to increase your power range, and harness what your Mazdaspeed3 is capable of. Note: Will require additional tuning!

 

CorkSport Mazdaspeed Downpipe

Doesn’t matter if you go with a high flow catalyst or opt-in for one without, the choice is yours. However, if you want to utilize its flow you are going to have to upgrade to a bigger diameter. Our 80mm one does really well, plus it sounds GREAT.  Note: Will require additional tuning!

The CorkSport Cat Back Exhaust System gives your new 2016 Miata the power it needs without the annoying drone.

CorkSport Cat-Back Exhaust

It’s no secret that car engines are just big air pumps, the faster you can shove air into the engine and how fast you can expel it efficiently is what it takes to make more power. No need to run the stock 63.5mm exhaust when you can run our 80mm (like to wake up the neighbors every morning, go with our non-resonated, you can’t beat the cold start)

CorkSport Top Mount Intercooler

If your power goal is 450whp or less you can get away with just upgrading your TMIC and be on your way and they look great in your engine bay.  Note: Will require additional tuning!

If you have the 2nd gen you can really utilize that hood scoop from the factory.  Not only that but you can even see a noticeable performance gain with our larger hood scoop and a TMIC set up.

 

When it comes to your Mazdaspeed we know you want to create safe power and harness the true potential of your ride. Be sure to build upon the proper foundation and head in the right direction for your build. Our techs are available for any questions you have and are ready to assist with planning your Mazdaspeed build path! Any questions – give us a call directly – (360)260-2675, email to sales@corksport.com or leave a comment and we’ll get back to you!

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