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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CorkSport CST6

Testing & Validation of the CorkSport CST6

As we get closer and closer to announcing the launch of the new CorkSport Turbo Line-Up we want to share the testing and validation we put our turbos through.  You may not realize it, but we’ve already shared a lot about the CST6 without really saying so, check out Barett’s Built Gen1 Here.  

So we’ve talked a bit about the design intent behind the CST6; defining the wheel sizes, wheel size ratio, and the ball bearing CHRA.   If you’ve seen the teaser listing then you’ve already seen the 633 whp dyno graph, so we’ll look at the data to support it!

The First Look at the CST6 Performance

CorkSport CST6 dyno at 28psi
CST6 running at 28PSI

First let’s look at the CST6 at a more moderate boost pressure.  Above are the results of back-to-back testing comparing the XS-Power V3 Exhaust Manifold and the upcoming CorkSport Cast Exhaust Manifold.  All dyno runs were performed with the same 28 psi peak pressure tune.

So the exhaust manifold testing is exciting, but it’s not what we’re here to discuss.   What I want you to know is that the CST6 is fully capable of providing mid-500 whp power at 28 psi.   While we have and will continue to push the CST6 to its max ability, the 27-30 psi range has proven to be a sweet and efficient spot for the CST6.

Testing the Limits on the CST6

CorkSport CST6 Dyno Graph running 34psi
CST6 running at 34PSI

Searching for the limits with the current fuel system we can easily push past the 600 whp mark plus some.   The efficiency of the CST6 at this power level is still very strong and the turbo continues to pull through the RPM range.   What really makes the CST6 shine is the power under the curve. This is a BIG turbo and will respond like one, but the loss of early spool is easily compensated for with the abundant power curve and power that carries past 7500 rpm.  

It’s important to note that testing for the CST6 is not finished because we are currently limited by the fuel system on the vehicle.   The current fuel system is OE DI injectors paired with a boost based methanol system flowing 40 gph peak. In the near future, we will continue finding the limits of the CST6 with a true port injection system and Split-Second controller flowing E85.   This will give us headroom for 8000+ rpm and boost levels past 34 psi (let’s see what 40 psi give us!).

Looking at the CST6 Data Log

CorkSport CST6 Data Log
MAF Voltage and Actual AFR of the CST6

This is a datalog form the 633 whp dyno run and was recorded on the chassis dyno.   Because of that, it is not a perfect example of street driving… let me explain why. The dyno dynamics chassis CorkSport uses can control load and thus the rate at which the engine can rev through the RPM range.   In order for us to dyno a vehicle at this power level safely, we need to find the right ramp rate for low RPM and high RPM. The biggest factor this affects is the spool RPM of the turbo.

On the graph I marked ~200 rpm shifted to the left for the boost curve.   On the street, the CST6 spools about 200 rpm sooner due to the higher load on the street vs the dyno.   This puts the CST6 @ 20 psi around 3800-3900 rpm.

Also shown on the graph are MAF voltage and actual AFR.   Both of these are important because they provide real data about how the vehicle is being tuned.

Target AFR is set for 11.76 which is neither rich nor aggressive for this setup.  The slight up and down of the AFR curve from 3500-4000 rpm is due to the very high amount of auxiliary methanol starting to spray along with the DI injectors.

Looking at MAF voltage you can see us get well past 4.50v.  Actually, we are consistently seeing MAF Voltage around 4.65-4.70v using the CorkSport 3.5” Intake which has a true ID of 3.50”.  This is just further validation that the CST6 is flowing enough air to support 600+ whp.

There’s more to come from the new CorkSport turbo lineup so stay tuned for more info on the CST5, CST6, and EWG housings.

-Barett @ CorkSport

Dyno Numbers and You

We talk a lot about dyno testing and seeing improvements with CorkSport goodies but we rarely talk about what dynos are and why dyno testing should be a part of your build. While e-tuning using logs and v-dyno works great, tuning on a chassis dyno can be quicker and is a just a bit safer; since let’s be honest, 4th gear WOT pulls in your local area of “Mexico” can get a little sketchy sometimes. Keep reading on for some advantages of knowing your dyno numbers.

To start off, I wanted to share a little bit of knowledge of what a dynamometer (dyno for short) is and how they work. Dyno is a broad term for a machine that measures force, torque, or power. In the automotive world, we typically think of a chassis dyno that measures torque through the drivetrain of a vehicle, however, for high-level suspension tuning, shock dynos also exist. Now some of you may be surprised to hear that dynos measure torque, not horsepower. Torque is much easier to measure and can be easily converted to horsepower (HP equals torque times RPM divided by 5252 for those curious).

There are a couple names of dyno you have likely seen get thrown around: Dynojet, Mustang, Dynapack, and DynoTech to name some of the most common. Each measure power a little differently but for the sake of keeping things concise, each uses a known or controlled “resistance” to fight the vehicle’s torque that is being produced.

Dynojet and some Mustang dynos use a physically heavy drum while Dynapack, DynoTech, and other Mustang dynos use electricity or hydraulics to control the dyno’s “resistance”. Each type of dyno has its own set of advantages & disadvantages but the most important thing to remember is that they will read differently for the same vehicle. This means if you are getting your car tested or tuned on a dyno multiple times, be sure to use the same type, and better yet same exact dyno, to really see how your build has affected your horsepower & torque.

On to advantages of getting your car dyno tested. While most are not “make it or break it” changes, dyno testing can really take your build to the next level.

Bragging Rights: While an obvious one, dyno results make it much easier to compare your car to another since you have hard data to back you up. This is especially true if you are using the same type of dyno. On a lighter note, comparing your car to someone with a well-documented build can help you decide what your next mod will be.

Ease of Tuning: Consistent and accurate pulls can be had back to back on a dyno, without having to drive out to your “dyno road” after every small tuning change. In a properly setup environment, pulls will show only tuning changes instead of having to worry about every little variable that comes with on-road pulls. If your tuner is in town, having them live tune with your car right in front of them can turn a multi-week e-tuning process into a long afternoon. Plus, you won’t have to worry about an expensive ticket from the local boys in blue.

Monitoring Car Health: Friend has the same car, same mods yet are making much more horsepower? Dyno testing can show things like this that may indicate a big problem with your ride. Removing the “driver mod” from racing your friend light to light can help determine if there’s something more going on. In addition, having hard data on power & torque numbers can tell you when to stop pushing for one more psi, keeping your ride on the road and not in pieces.

New Mod Validation: Bought a part and want to see what it’s doing for you? A dyno before and after is a great way to validate your new mods and see what your next step should be. In addition, you may find out there are more benefits to a part than just max power gains. Maybe that newest part only gave you +2WHP at peak but shows gains of 10-15 through the middle of the rev range, or you can hold power to a higher RPM. Analyzing dyno graphs for more than just peak numbers is a powerful tool that can indicate how a part changes how a car feels.

Obviously, not everyone has access to a dyno and it is usually expensive to use a dyno for more than a few pulls, however, it is worth it and can give you some much-needed info about your ride while keeping you & your ride safe and out of legal trouble.

Looking for a dyno for your car? We are hosting the 2018 CorkSport Dyno Day in August. Dyno runs, food, a car show, and even drag racing are all on the agenda. Check out the Facebook event page for full details & don’t be shy if you don’t have a Mazda-we had a Fiat 500 Abarth on the rollers last year!

Hope to see you there!

-Daniel

Boosted Down the Rabbit Hole

“Intake, test pipe, and a tune ONLY” was my mantra.  I’d just bought a shiny new ’13 tech package VRM MazdaSpeed3 with the extended warranty, 3 miles on the odometer as it rolled off the lot for the test drive.  Via the web forums (back when MSF was still popular), I had performed my due diligence in terms of where I was headed with this ride. I knew what my mods would be, the results to expect, and even learned a bit about the tuning process, all with the intent to “stock out” in less than an hour in the event I broke something on the car.

But… the local Nator chapter wrapped their slithering hentai tentacles around me, and those thoughts of a mildly tuned car with the manners fully intact started to erode.  The friends, the fun, and the performance results were an instant addiction.

In just a few short months I had sold that warranty back and started down the rabbit hole.  Trips to Epic NATOR Meets were a terribly awesome influence, seeing cars on the bleeding edge of the DISI Mazdaspeed platform, and meeting several of the prominent people in the Mazda community that were so forthcoming with their knowledge.  The hook was set!

I found myself pursuing information, and if there wasn’t any data to be had, I wanted to make it myself.  I tested and cataloged a variety of items, from NVH with motor mounts to compression test compendiums (yes Cylinder 3, you deserve that BAD rap!), meanwhile moving along the mod path to a medium turbo, front mount intercooler, and a methanol kit.  Once I purchased a spare long block, I knew I was getting in ball-joints deep.

Fast forward to today.  I’ve been very fortunate to be chosen to test products for a handful of vendors!  With an aligned focus – direct fit or minimal fabrication parts – I’ve reached my (probably temporary) goal of 500 wheel horsepower! Where I’ve tested the limits of products/parts for many companies – whether they have asked me to or not. The CorkSport 3.5 Bar Map Sensor is a solid example of exceeding the envelope, as I did manage to over boost while playing with my EBCS configuration, and pegging it at 37.58 PSI. (At 900 ft. ASL)

 Corksport asked me to describe my modification journey and how their beta parts have impacted my build and decisions, so there is no slight intended to the multitude of other people involved in my project – that list is not short.

I’ve run the Corksport intake manifold for nearly 2 years and just prior to the big turbo transition.  

  • It gained 12 g/s flow on the identical tune and no other modifications, so I knew it was an immediate upgrade.
  • I’ve been hammering  30+psi through it for the majority of that time, and my built engine is approaching 25 thousand miles with that duress.  
  • The spark plugs have been pristine and uniform, indicating to me the flow is balanced in the runners.  
  • There is no better fitting upgrade intake manifold for the platform.  

The beta-testing portion of this journey has been pretty awesome. Constant emails and conversations back and forth with the CorkSport Engineering team, and support from installation, to checking in periodically afterward to see how the system is running and the part is performing for me and my particular set-up. I understand that I am not the only one to have been running this part as a beta-tester, which just shows how thorough this company is with it’s beta-testing.

Barett, the CorkSport engineer, was probably annoyed with the ‘data-whore’ aspect of who I am, but man was it fun! Tracking my progress throughout, and sending info back and forth fed the logical performance driven sides of me for quite a while.

The manifold was recently combined with the Corksport 72mm throttle body, which takes advantage of the IM’s oversized opening, which I feel will scale up with even more power should I get the itch for ludicrous speed.  There is zero loss of drivability with the TB mimicking the factory unit electronics and nothing for your tuner to battle with like the old days of trying to open up that choke point.

While it’s usually about performance parts for me, I have to say that I run a few of the CorkSport “comfort” pieces and can genuinely say they are worth the investment. The CorkSport Performance Steering Wheel is just amazing! The contoured grips are a tremendous comfort for long drives, and the beefy upper section is awesome for the twisties in roads like the “Tail of the Dragon” in NC. It’s also shown no signs of wear in the last 2 years, and I look forward to driving with it for many years to come.

I was lucky enough to get the CorkSport Hood Strut kit when they were available, and now my hood opens significantly more than the prop rod and facilitates installing those go fast bits. (Hopefully, CorkSport gets wise and brings them back for sale again).

I would like to thank Corksport for giving me the opportunity to test their parts, in addition to many others, and YOU for taking the time to read my cool story, bro!

Spread the boost – there is no vaccine!

Jason

25 hours of Thunderhill

25 hours of 69

For many people across the USA, the days after Thanksgiving means one thing. To them, it’s the start of the Christmas season. The beginning of holiday shopping, pumpkin spice lattes, and the best home cooked meals you can’t wait to dive into.

However, for a small select few group of individuals and teams, it’s a time for something completely different. It’s a time to see what you are made of, a time to put it all out on the table. A time where you know if the past year of planning, testing, and preparation are about to reward you greatly or tear you down completely. It’s the time where you hope to be able to stand up on a Sunday at noon and can say proudly “I survived the 25.”

For those lucky few (some call them crazy or stupid) the weekend after the Thanksgiving Holiday is what you might call a different type of holiday.

For the past 15 years, the 1st weekend of December is when some of the worlds best pro and amateur drivers descend upon a small city in Northern California known as Willows. Just on the outskirts of this quaint little city lies a little well-known road course titled merely “Thunderhill.” Now what makes Thunderhill so unique, well it’s probably the fact that this venue host the longest and most extreme endurance race in all of North America. For 25 hours straight; teams, coaches, drivers, and fans endure the rain, cold, dark, lack of sleep and more to try and make a name for themselves, and this year CorkSport did just that. Made History…

 

 

While attending the 25 Hours of Thunderhill is nothing new for CorkSport as we have spent the past several years supporting Mazda North America and their racing efforts with logistics, crew, and parts. This year was the first year where we entered a new team ourselves and brought our car, crew, trailer, and everything else you need to try and survive 25 hours of racing.

Sadly MNAO did not attend this year so it was up to us to make sure that the brand and name would make a forceful showing at the event and that is precisely what we did.

 

 

To start this whole thing off, we brought out our 2016 Mazda 3 GT. You guys are more than familiar with this car as Co-owner, and founder of CS Derrick Ambrose has been piloting this ride for two race seasons now in SCCA racing. We spent several weeks leading up to the event preparing the CorkSport Mazda3 for this daunting task.

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We got extra safety equipment installed, upgraded our data acquisition package, optimized and engine tune for the  2.5L engine, and even installed some upgrade prototype pieces to have the car suited for the race.

Some of the CS goodies that were on the car during the run where our SRI, Cat-back exhaust, RMM, sway bar, and some prototype pieces like our aluminum skid tray and upgraded transmission engine mount. We needed the best parts we could get in there if we wanted to be competitive and make history.

No one has ever raced the 3rd generation Mazda 3 for this long in any endurance race. This car started off just like any other Mazda 3 and still retained a full OEM chassis, transmission, and engine. The engine internals where untouched and the transmission received a CorkSport LSD.

 

The team showed up on a brisk and cold Thursday morning, and we went to work. We immediately set up and got the drivers briefed. We got some practice in on Thursday followed with some qualifying on Friday all to be prepared to push this car to the limit for 25 hours. The team grabbed the pole position, and we were 1.5 seconds ahead of the next car which was fantastic. It showed we had the pace and ultimately the faster car. Fast forward to Saturday, and the flag drops green.

We had a great start and excellent drivers in the car. We struggled a bit through the night with consuming tires at a rate faster than we had anticipated and also had a few issues with how quickly we could get fuel into the car, despite the problems the team and the car pushed through the night. With just a brake change and tweak to the exhaust through the night, we maintained a good pace that ultimately got unwound due to the fuel issue mentioned above.
There was a Miata in our class that could get better fuel economy and tire consumption and slowly crawled there way up to lead during the night.

As the sunlight begins to break through, we are in a healthy 2nd place but a bit far off the leader, however, it does not worry us too much as we still have a shot at a win. Things were looking good till right about hour 22. One of our driver’s radio’s in and let us know he lost 4th gear (that’s not good). None the less we keep pushing knowing we have a spare transmission should we need to swap.

 

Now at hour 23 we get another message. “I lost 2nd gear” The transmission has now lost two gears, and we get a bit nervous. The car is still going and driving strong but our lap times do suffer from not being able to use all of the gears. After a quick powwow with the team, the decision is made to leave the car out on track and finish the race between 3rd and 5th gear.

With only 2.5 hours to go swapping out the transmission did not make sense as we were very secured in 2nd place. So we did just that and pushed on through, and you know what happened? We did it. While we didn’t get the P1 spot like we had wanted we did what no other SKYACTIV-G Mazda3 had done before.

We survived the 25. We proved the chassis and the platform, we pushed harder, longer, and further than absolutely anyone else has. The car was relatively unscathed, and minus the transmission, the vehicle performed excellently. All of the CorkSport parts did precisely what they needed to and outperformed all expectations.

We took the 3rd gen platform and solidified it as a competitive car and chassis that can be used and used well at all levels of motorsports.

So, what happens next?

The Mazda 3 made it back home and now lay dormant inside of HQ. We will be spending the next few weeks going through a ton of data and running through the car with a fine tooth comb.

We’ll take the transmission apart and see what her demise was. We’ll likely strip the SKYACTIV 2.5L down as well to check out what two years of racing looks like on her. The oil is already out of the car and on its way to the lab so be sure to stick around and see what we find out there.

Now one of the great things about this is what our success brings to the community. Everything we learned here can and will be applied to all of our parts and products moving forward. When we win, you guys all win. So, celebrate our accolades with us and wish us luck as we begin to prepare for the 2018 race season.

 

Do we tackle the 25 hours again next year? Do we show up with a turbocharger and more aero? And do we fight our ways to a P1 finish? You better believe I am going to try.

 

-Vincent