Mazda 6 Turbo Lowering Springs Release!

2018+ Mazda 6 Lowering Springs

We at CorkSport are happy to introduce the Sport Lowering Springs for 2018+ Mazda 6 equipped with the 2.5L turbocharged engine. In our last post, we talked about the height, handling, and quality of our new springs. If you haven’t seen it, check it out HERE. Today we’ll cover how we tested the ride quality and go a step further to talk about damping and natural frequency. I’m going to warn you now; this gets a little bit complicated, but we’re happy to answer any questions you may have.

Spring Damping

Let’s start with a basic example–your car hits a bump which compresses the spring. It “springs” back to its normal length. In a perfect world with no friction or damping, the springs in your suspension would keep bouncing up and down forever, this is called oscillation. Add back in dampening and friction, and the spring will settle out to its normal length pretty quickly. How different strengths of damping affect the “oscillation” can be seen in the graph below.

Spring damping graph
Spring damping example.

The car has hit the bump at the bottom left of the graph. As time goes by, you can see the spring expand and compress and so on. The Greek letter is not important but what is important is the numbers. When it is 0 (black line) the spring compresses and expands over and over to the same height. As the number increases, you can see that the spring returns to its normal length faster until it gets too large and overpowers the spring (dark blue line). For a car, the 0.4 to 1 range is ideal as there is minimal “bouncing” without having too high of damping.

What does all this mean though? Let’s say from the factory the car is in the 0.7 range (orange line). If we went to a drastically stiffer spring, but kept the OEM dampers, we may end up in the 0.2 range (light blue line), which would be uncomfortable due to all the bouncing every time you hit a bump. The CorkSport front and rear spring rates chosen are small enough of a change to fit well with the OEM damping, ensuring no bouncing.

Stock 2018 Mazda 6 and CorkSport Modified Mazda 6
Stock height vs. CorkSport Springs

Natural Frequency Analysis

To go along with this, we did some natural frequency analysis. Natural frequency simplified is how quickly the suspension responds to a bump. Higher the natural frequency, the harsher the ride in a car is. Most “regular” production cars sit in a 1.0-1.6 Hertz (Hz) range for a comfortable ride. Sports cars are usually in the 1.6-2.3Hz range. Full race cars are usually 2.3-3.0 or even higher. An average person will start thinking a ride is stiff/harsh at around 2.0-2.2Hz. Using a special app that ties into the accelerometers of a cell phone we can approximately measure the frequency of a specific suspension setup. With stock suspension on the Mazda 6 2.5T, this yielded ~1.4Hz front and ~1.7Hz rear.

With a stiffer spring, these frequencies will increase, but we wanted to be sure to only increase them slightly, to not severely affect comfort. We went through a few different combinations to get our ideal result. Our final setup ended up at ~1.5Hz front and ~1.85Hz rear. This is enough to notice the suspension feels “sportier” without riding harsh.

2018+ Mazda 6 Roller Shot

There is one other big thing to highlight with frequency. Notice that both the OEM and CorkSport springs have a higher rear natural frequency than front. If your natural frequency front to back is close to equal, the car has a tendency to “pitch” front to back over bumps. Since your rear tires hit the bump slightly later than the fronts, to have a comfortable ride the rear suspension has to “catch up” to the fronts to prevent this pitching back and forth. If a frequency is too much higher in the rear, it can be too fast for the fronts and cause the same pitching issue.

Natural frequency was always on our minds when designing the CS springs and we tested a bunch of different combinations to determine the optimum balance of ride and handling.


That about does it for the Mazda 6 2.5T Sport Lowering Springs. Be sure to let us know if you have any questions-suspension is hard, even for us! Lastly, be sure to share your MZ6T with us by using #CorkSport.

-Daniel @ CorkSport

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Performance Exhaust for the 2018+ Mazda6 2.5T

Mazda did a great job bringing a turbocharged engine back to the Mazda 6 (Mazda 3 next please?), but may have done too good of a job of keeping it quiet. Say hello to the CorkSport 80mm Cat Back Exhaust for 2018+ Mazda6 equipped with the turbocharged 2.5L engine. If you’re interested in waking up your SkyActiv-T in both excitement and power, read on as we breakdown the newest CS exhaust.

As with all CorkSport exhausts, the goal of the MZ6 2.5T exhaust is to improve power and sound by improving the flow of the OEM exhaust. We started by increasing the size of the piping from 60mm to 80mm. That is an increase of over three-quarters of an inch to really help your turbocharger breathe better. In addition, the CS exhaust system eliminates the crushed areas present in the OEM exhaust and replaces the restrictive muffler sections with pass-through resonators. These resonators control volume and drone without affecting power output.

All that extra flow does mean a power increase. In our in-house dyno testing, we saw an increase in 5-6WHP just by bolting on the CorkSport  Cat Back Exhaust. Check out the dyno sheet down below to see. This increase came with no tuning changes, no check engine lights, and the only other mod being the CorkSport Short Ram Intake, which was installed for both tests. With the 80mm piping size, this exhaust is ready to support future modifications and would likely show more power gains with proper tuning.

The CorkSport MZ6T exhaust is more than just function. We went through multiple iterations and designs to ensure the best sounding exhaust for your 6. The finished product ups the volume without being annoying to daily drive yet still sounds great when in hard acceleration. We strongly recommend you watch the video below to hear what to expect from this exhaust.

To give a great looking, long-lasting finish to each exhaust, they are manufactured from fully polished 304 stainless steel. To ensure a high quality fitment, all components are precision TIG welded together on jigs made from OEM exhaust components. Lastly as a finishing touch, we use 100mm dual wall exhaust tips. They fill out the bumper cutouts and are extended slightly to give a classy look and enhance the new Mazda 6’s styling.

The CS Mazda 6 Turbo Exhaust comes with all the hardware and gaskets you need for installation, high quality instructions, and CorkSport support for any questions you may have. Pick up a CorkSport MZ6 2.5T Exhaust today and liven up that daily commute.

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!

3 Turbos and a Supercharger for Mazda

A year ago we were all complaining at Mazda saying “where is the forced induction?” and it looks like Mazda was listening.

First up is the Mazda 6 turbo which Mazda has priced to sell as you can get into a GT Mazda 6 turbo pretty affordably.  Granted there is no manual gearbox but I can say first hand they are fun to drive and the torque from the boost is really addictive.  I find it hard to not want to screw with people in the 6 since it has no visible exterior queues that it has a turbo. I will say we have already been tweaking on the car and found that it does respond well to modifications.

Second up is the SkyactivX which Mazda says will be available later this year.  This engine is supercharged to allow it to be an HCCI engine, aka compression gas motor.  The forced induction setup is pretty tricky and the initial look I have done with it I get we can crank it up a bit more to improve the efficiency of the intercooler to give it more heat capacity to allow you to use the boost longer in the car for high performance driving.  Until it shows up we won’t know for sure but we are looking forward to trying it out.

Third is the Mazda 6 diesel which uses 2 turbos.  Mazda tried to release the 6 in the past but when they couldn’t match what VW was doing they declined to just “Send It” as the car didn’t perform as they needed it to and still hit the emissions targets without urea injection.  Later we all found out VW was a cheating bastard which kept us from having the Skyactiv diesel engine here to crank up the boost on. About every publication in the planet has posted up about the 2018 Mazda 6 diesel being seen in the EPA parking lot for testing along with a pile of other diesel models.  This is a good sign if Mazda says it will pass the US emissions and handed one over to the EPA we can expect it and soon.

I am going out on a limb here and saying that besides the announced Mazda 3 Skyactiv we are going to get something fun in the new Mazda 3 ~ a year after the initial release.  If you are reading this Mazda, please give us a Mazda 3 GT with a turbo motor.

-Derrick