In case you missed it, we have been working on improving the flimsy rubber tube that comes stock on the cold side of your 2018+ Mazda 6 2.5T. Check out the first part on the cold side boost tube here and the full OEM piping & intercooler breakdown here. Since our last installment, we have been busy testing a prototype CorkSport Boost Tube and would like to share some results with you all.
Starting off we tested and data logged both the OEM tube and CorkSport Performance Boost Tube on the dyno. We were not expecting to see too much of a difference to power with just the boost tube changing however, we did see tiny improvements here and there, most notably way up at the top of the RPM range.
Check out the graph below, OEM=red, CS=green. We tested on the same day in identical conditions and the car had a CorkSport Intake and Cat Back Exhaust installed for both tests. PLEASE NOTE: the variations below 2800RPM are due to inconsistencies associated with dyno testing an automatic car.
After noticing these changes, we went to the data logs to see how the boost changed between the OEM tube and the CS Boost Tube. The graph below shows the engine RPM versus the manifold pressure in psi. Both lines have the same smoothing done to the raw data. As you can see, the CorkSport tube (green) holds about 0.5psi through the midrange (3500-5000RPM) and is almost 1psi more when above 5500RPM. This correlates well with what we saw while dyno testing.
The small increase in boost pressure is likely due to the CorkSport tube not expanding as much when under pressure. To confirm this, we capped off both ends and pressurized the each tube to 20psi. Note: do not try this at home as the caps can easily fly off and injure you.
After measuring multiple locations both before and during pressurization, we found that the OEM tube expands about 12% in internal cross-sectional area while the CorkSport Boost Tube expands 3x less at 4%. Keep in mind that this would be an even larger difference if the same test was performed with the tubes installed on the car due to the heat of the engine bay. Since silicone is more stable than rubber at high temperatures, the heat of the engine bay will not soften it nearly as much as the rubber OEM boost tube. A softer rubber tube would mean even more expansion when pressurized and even more inconsistent boost pressures.
This data may not show drastic changes but it does not tell the whole story. The larger diameter and thus larger volume of boosted air of the CS tube provides a little bit better response when low in the RPM range. While this may just be a placebo effect on our end, there’s not too much of a wait before you can try it yourselves! Stay tuned for more information. If you want a more serious upgrade though, keep your eyes out for information on the upcoming CorkSport FMIC kit and Piping Upgrade kit!
P.S. 2016+ Mazda CX-9 owners and future Mazda CX-5 2.5T owners, don’t worry we will be checking this for fitment along with other CS goodies!
-Daniel @ CorkSport
SkyActiv 2.5T Cold Side Boost Tube Part 2: Testing January 18th, 2019CorkSport
4 years ago, we released the 60.5mm Exhaust kit for the 3rd Gen Mazda 3 (both in axle back and full cat back flavors). It’s certainly been a hit, but there has been a few of you longing for more noise. Today we are proud to announce the 80mm variant of our cat back exhaust for the 2014-2018 Mazda 3 Hatchback and Sedan! At this time, just the hatchback version is available, but we will have the Sedan version ready in just a few short months.
Now I know what you’re thinking, an 80mm exhaust seems excessively large for a naturally aspirated car making less than 200whp. But, hear me out because I think you’ll like what’s coming.
80mm piping allows for some unique & louder tones its smaller little brother can’t offer, but it wasn’t as easy as just using the old design and making the pipes larger. We had to do quite a bit of resonator experimentation and NVH analysis to get to the finished result with as little drone as possible. I’ll be upfront with you guys though, this is loud. It’s a good loud with tons of fun noises, but if you’re looking for something subtler, then our 60.5mm cat back or axle back may be a better fit. We do a good job of capturing the audio for you though so you have a good understanding of what you’re getting. Be sure to check out the product video to hear it.
For those wanting this more aggressive exhaust note, sound isn’t the only bonus. We thought about the appearance, and how we could take advantage of this time to tinker with the design. The 80mm does a nice job of not only filling the exhaust tunnel under the car, but the axle back portion is a bit more prominent when you catch a glance.
On the Hatchbacks, the exhaust tips got a nice size increase up to 100mm and they are slant cut to help follow the profile of the bumper. Sedans have also been upsized to 100mm tips, which were lowered slightly to ensure your bumper doesn’t melt with the large piping. This has the added bonus of making the tips a little more visible from the rear and side of the car. In both cases, the way the upsized exhaust accents the rear of the car provides an aftermarket look, that’s classy and somehow the way it always should have been from factory. I
As with every CorkSport exhaust, this new 80mm variant is made from fully polished T-304 stainless steel for long lasting corrosion resistance. All flanges, hangers, and resonators are precision TIG welded in place while all of the piping is made with smooth mandrel bends. Each resonator uses a direct flow-thru design to keep the drone down and the volume up without sacrificing power.
Speaking of power, check out the dynograph below. The upsize to 80mm showed similar power gains as the 60.5mm variant, so the extra size isn’t really needed at similar to stock power levels (aside from the great noise of course!). The only change in parts or tune between the two graphs was the exhaust. OEM exhaust (red) vs. CorkSport 80mm Exhaust (green).I
We also believe it’s also very important to be prepared. Future proofing your car for mods down the road is always a great idea, and you’ve probably heard that we have a turbo kit (yes it’s still happening!) and race header in the works. More on those projects later, but I’ll let you put 2 & 2 together…
We recently went over the stock intercooler & piping system for the 2018+ Mazda 6 2.5T. If you missed it, be sure to check out the blog HERE.
Today, it’s the first look at the CorkSport parts that will be coming in the near future to remedy the issues we found with the OEM system. We are not covering our upgraded intercooler just yet though; today’s focus is piping upgrades!
As you can see we’ve been busy getting the upgraded intercooler piping designed & 3D printed for test fitting (while you can’t see it I promise the cold pipe is hanging out in there too!). I’m happy to say there’s plenty of room to fit the upgraded piping sizes that we were targeting and hopefully they will net us a few HP gain without any other changes.
These horsepower gains typically comes from removing sharp bends and diameter reductions in the stock piping that cause pressure losses. Then, the turbocharger can operate more efficiently to reach the desired boost level. Now how about some more detail on how and why each pipe has changed.
Starting off with the hot side of things (piping from turbo to intercooler), check out the CAD image above. As you can see, the OEM piping (left) is smaller than the CorkSport piping (right). In fact, we plan to use 2.25” piping for the hot side. Note that the plastic OEM piping is much thicker wall than the CS aluminum piping so even if the outer diameter looks similar, the inside diameter is much larger.
In addition, we keep this same inside diameter throughout while the OEM piping has a major diameter reduction through the middle. For those of you coming from a Mazdaspeed 3, 2.25” is the same size used on the hot side of all CS intercooler kits and has proven itself to support 600+WHP on Barett’s car (more info on that HERE). While we know the Sky-T may not be to that level just yet, 2.25” is a great size that gets the hot air to the intercooler as fast as possible while retaining high horsepower capabilities.
It’s not all about size though. Instead of using many tight radius direction changes like OEM, the CorkSport hot pipe uses smooth, large radius mandrel bends throughout. This means smoother and faster airflow to your intercooler. Lastly, you may notice the CS hot pipe is significantly longer than the OEM hard plastic unit (the OEM rubber tube starts at the connection point circled in the image above). This reduces the amount of flexible connector used, limiting what could expand at high boost levels. That being said, the CorkSport kit will use high strength silicone with four fabric reinforcement layers to prevent any expansion anyways.
The cold side of the system was already a decent diameter from the factory, but as you can see, we went even larger. The rubber OEM cold pipe will be replaced with a 3” diameter aluminum pipe. This large diameter pipe and huge volume of air that comes with it right before the throttle body has proven to help throttle response and reduce boost lag on our GEN2 Mazdaspeed 3 FMIC kit. We hope to get much of the same from the SkyActiv 2.5T. The cold side also uses large radius mandrel bends for smooth and fast airflow.
Lastly, the cold side piping reduces the amount of flexible connector used. And just like the hot side, each end of the pipe will use 4-ply reinforced silicone to prevent any expansion under high boost levels.
Those of you with a keen eye will have realized that our planned silicone connectors do not use the same connection style as the OEM intercooler. This is for good reason: we believe that the OEM intercooler will run out of cooling capacity before the OEM piping really becomes an issue. So a piping upgrade by itself wouldn’t show too much of a performance advantage.
In addition, we were able to design the piping to be the best it can without using the constraints of the OEM intercooler. So yes, the upcoming CorkSport intercooler upgrade will be required for the CS piping upgrade to work, but it’s so the CS piping & FMIC combo can be the best it can be for you all!
For those of you that have stuck around this long, check out this tease of a CAD model of the CorkSport FMIC & Piping kit.
And just because we like teasing you, check this early prototype out. Testing to come soon!
Stay tuned for more, as next time we will cover the intercooler itself. Also let us know your thoughts down below, we love your input!
-Daniel @ CorkSport
SkyActiv 2.5T: Let’s Talk Intercooler Pipe Upgrades January 8th, 2019CorkSport
Many years ago we helped bring a revolutionary design to the Mazdaspeed community. Fast forward 4+ years and you’ll find that the CorkSport Tokay Injector Seals are still the best option for your Mazdaspeed.
Recently, we had a customer ship their stock block engine core to us for a fresh Dankai 2 Built Block. During the engine core tear-down and inspection, we found a set of CorkSport Injector Seals installed. We realized this was a great opportunity to share what we found with the community.
When the CorkSport Injector Seals arrive at your door they look like this:
Brand new a fresh of the lathe with all of their beryllium copper brilliance. After many thousands of miles of use and abuse they look like this:
Now to the untrained eye you may think they look bad, but the truth is they look fantastic! The visible top of the seal has a small amount of carbon deposits present. This is to be expected because this surface is exposed to the combustion chamber. Moving to the side of the seal you can see a distinct clean edge and no carbon deposits on the sides of the seal. This distinct clean edge is where the exterior of the seal is designed to seal in the cylinder head. This is awesome!
Now let’s look at the inside of the used seals:
Again we see carbon deposits, but they are in and only in the expected locations. Moving up the side of the seal you can see a “shelf” or “step” that is clean. This is the edge that the fuel injector seals against. Beyond that the inside of the seal is clean.
From this inspection we can see that the injector seal was functioning as designed and doing its job effectively.
So you might be asking…”What is so special about this design?” Well, we wrote a two-part design blog answering that exactly. We highly suggest spending the 10 minutes to read these.
This is exactly why every single CorkSport Dankai Built Long Block includes a set of CS Injector Seals, but if you’re not looking for a built block but still want the assurance of the CS Seals you can check them out right here. The install of the seal can be a bit tricky sometimes, especially getting dirty injectors out of the cylinder head. Because of that we’ve developed an injector puller tool that makes the job MUCH easier.
We hope you enjoyed this quick tech inspection of the injector seals! Thanks for tuning in with CorkSport Mazda Performance.
-Barett @ CS
MZR DISI Injector Seals – The Correct Seal for YOUR Speed January 7th, 2019CorkSport
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 beingthe 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.
Performance Exhaust for the 2018+ Mazda6 2.5T December 27th, 2018CorkSport
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