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

Welcome to the Gen3 Mazda 3 Suspension Package

Want to upgrade your suspension system on your Gen3 Mazda3, but don’t want to deal with the headaches that come with lowering springs or coilovers?

Introducing the CorkSport Adjustable Shock/Strut Assembled Package for 2014+ Mazda 3. This truly is a complete package that includes CorkSport lowering springs, CorkSport adjustable shocks/struts, and CorkSport camber plates all assembled and ready to install.

 

 

We’ve discussed before how the CorkSport adjustable shocks and struts are a great compliment to the CorkSport lowering springs. Now we have included them together in a package with our camber plates to give a huge handling and adjustability upgrade to any Gen3.

In addition, this package comes assembled with new OE dust boots, pivot bearings, and bump stops that are even cut to proper length to match the lower ride height. Since this package comes assembled with new parts, installing it is a snap. No spring compressors needed at any point. Check out the image below to see exactly what you get in every box.

 

 

Whether you are looking to replace some worn out OE components and get a style bonus, or are looking for some and handling and adjustability for your racecar, the CorkSport Adjustable Shock/Strut Assembled Package can help you reach your goal.

An Inside Look at the CorkSport EBCS

We recently came across one of the original CorkSport EBCS prototypes which gave us a perfect opportunity to break it down and give you all an in-depth look. Read on as I go through what makes the CS EBCS tick, and more importantly how it gives you great boost control on your Mazdaspeed.

Just as a refresher before we dive in, an electronic boost control solenoid (EBCS) allows for precise boost control by using an electric solenoid to help control the wastegate. A boost reference travels to the EBCS where it can either push on the wastegate diaphragm or vent to the turbo inlet pipe. Where the air travels is controlled by the solenoid.

Obviously, the specifics change slightly depending on a number of factors with the turbocharger setup, but the concepts remain similar. Since the solenoid is electronic, it can be controlled within a tune. This means you are not wholly controlling your maximum boost with the spring in the wastegate and can hit boost targets larger than the “10psi” spring in your wastegate. For more information on boost control and the different EBCS setups, checkout Barett’s white paper on the subject.

Now the above image is a little different from the way you are usually seeing the CS EBCS. Not only is it missing the sweet black anodized finish (early prototype remember?), it needs some assembly before it can function properly. Below lists the components in the system and a short description of what they do. Obviously, we are missing a few key o-rings to keep everything nice and sealed, but all the important bits are there.

  • Manifold: This is the air distribution block. Air/boost comes in one port and leaves through a different port. Where the air goes is determined by the bullet valve.

  • Bullet Valve Assembly: More on this later, but essentially the center rod (piston) moves in and out while the black portion prevents air from reaching one of the manifold ports as needed.

  • Tension Spring: Keeps the bullet valve in the correct position when the system is not energized.

  • Coil Seat: Ensures the copper coil stays in place so the valve can operate properly.

  • Coil/Windings: Creates a magnetic field when energized that moves center rod of bullet valve.

  • Solenoid Body & Wiring: Contains the coil and other components. Also attaches the valve to the manifold.

Each one of the “thirds” of the bullet valve corresponds to one port on the EBCS manifold. They are labeled accordingly above. As EBCS is energized, the piston of the valve is pulled by the magnetic field created by the windings. There is a small amount of movement; only about 12 thousandths of an inch (0.012”) to be exact, which is enough to allow air to either reach the wastegate diaphragm or pass by into the turbo inlet pipe. Again this is simplified as it does not touch on duty cycle-the valve is typically rapidly opening and closing (seriously, check out the white paper).

The bullet valve is advanced technology that offers the utmost in fast responding fluid control. In addition, its profile offers the ability to make a pressure balanced valve and have a manifold that fits just about anywhere. All of this tech means you end up making boost faster, minimizing boost spikes, and keeping boost creep in check. If you want the best in boost control for your Mazdaspeed, be sure to pick up a CorkSport EBCS.

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