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
A car club by any other name is just a group of enthusiasts getting together to celebrate their gains, reach out for support, gather advice and inspiration, and ultimately find a reason to connect.
With Mazda clubs, specifically Nator Clubs, there is a LOT more to it than just the benefit to you as a single person.
We recently sent Kim out to the Epic Nator Meet in Robbinsville, NC, to ride the trail of the dragon, reach out to the Mazda community, and just generally bring her personality to ignite the shenanigans at the event. If you’ve ever had the “pleasure” of meeting or hanging out with Kim, you know what we’re talking about. You never know what will be said, how loud it will get, or how late into the night the event will go… especially if there’s a campfire.
She came back with some good info, great shots, and some awesome stories that reignite our LOVE of the NATOR MAZDASPEED CLUB and the Mazda community as a whole!
From the moment she started to plan her drive from Richmond, VA, she was able to connect with a fellow west coast transplant, and make the drive in her rental following the Mazdaspeed booty. Stopping for coffees, food, and to refuel it was an awesome drive all the way to Robbinsville, NC.
Pulling in, the hotel parking lot was already full of Mazda’s, and what a sight for sore eyes it was! Good friends from Canada, Arkansas, Missouri, Illinois, Maryland, and so many other places! For those who had come in during the week, running the Tail of the Dragon had still not gotten old, and Mazdaspeeds were coming back from mid-day runs for dinner.
Nights filled with good friends, talk of cars, and connecting to just catch up were the basis of the meet, and hopping from one car to the next to get feedback and different set-ups and parts was awesome! No need to drive the Dragon in a rental when there are so many built Mazdas around!
We got reports of the spirit of the Nator Mazda community still being alive! With part swaps and repairs in the parking lot – all hands on deck, pickups on trailers for those with bigger issues, and unfortunately we saw the spirit of Nator in having one another’s backs as people as well! From fender benders to a hospital run to keep our squad safe and healthy!
There is nothing, and we mean it, absolutely nothing better than seeing what the Mazdaspeed Nator club is capable of when it comes to supporting one another, donating to a cause or raffle, and just genuinely having a great time!
Keep an eye out, as we will be sharing about our trip to the Mazda Takeover Event in Idaho very soon, and hosting our own event at the end of summer. There is very little that tops the feeling of being connected to a core group of Mazda enthusiasts, and from West coast to East coast, we do our best to stay connected and keep the spirit of the Mazda Community running deep!
Until next time, stay safe, stay fast, and stay happy my friends!
You may have seen some funny looking parts floating around on the CS channels that did not look like the typical aluminum or steel parts you install on your Mazda or Mazdaspeed.
These plastic parts are made through 3D printing, a method we use often in R&D to really understand the ins and outs of a part. We’ve been getting a lot of questions lately on our 3D printers so I thought I’d run through what they are, how they work, and what we use them for.
3D printing is quite a simple process even though it may not seem so to start. In normal manufacturing, you start with a block of material and cut away portions until you achieve the shape you want. In 3D printing, you add material (usually plastic) layer by layer until the shape you want is achieved.
For a lot of 3D printers, including both of the CorkSport printers, you can visualize a hot glue gun attached to a robot. The robot controls where the “glue” is extruded and once the first layer is complete, the robot simply moves the object downward slightly and another layer begins. The second layer attaches to the first and you slowly gain height and shape until your part is completed.
This method is uses plastic “filament” as the material fed into the machine. Think of a spool of wire but instead of being made of copper, it’s made out of a recyclable plastic. This material is fed into the machine where it is melted and extruded like the glue in the above analogy. Other 3D printers use liquid resin that is solidified layer by layer or a powder material that gets bonded together layer by layer. The image below shows an almost empty vs brand new filament spool for our large 3D printer. To give you some scale, that is a 4 inch inlet air filter next to them– 10kg is a lot of filament!
We have two printers at CorkSport, a large Gigabot, and a small MakerBot 2X. The Gigabot can print anything that will fit in a 2-foot cube which is more than enough space for the majority of CorkSport parts. The MakerBot is much smaller, only about 9.5” by 6” by 6”. We typically use the Gigabit for most of the R&D testing and the MakerBot for making cool stuff for you all! However, the MakerBot uses a different plastic material that is stronger and more resistant to heat, allowing the parts to be tested on a running Mazda (albeit for a short time).
Barett and I use our 3D printers as tools to aid in R&D. We can take apart directly from a design in SolidWorks to a physical object extremely easily. Once we are happy with a design, it gets saved as a “mesh” made up of hundreds or thousands of tiny triangles. This is imported into a “slicer” program that does just as its name says: slices the part into layers. The part information as well as the settings for the print is exported to an SD card, which we use to upload the information to the printer.
Once we hit “print” all we have to do is wait. Smaller parts like brackets and fittings can be printed in an hour or two while large parts like manifolds or intercooler piping can take multiple days. 3D printers enable us to start a print on a Friday afternoon and leave it like this:
When we show up on Monday, the print is complete, ready for a test fit, and looking like this (Mazdaspeed 6 FMIC Piping):
I can’t express enough how much easier it is to have a physical part to test fit than to try to measure in all of the awkward angles and spaces that exist in a Mazdaspeed engine bay and hope your design will fit.
Having the capability to make a quick and inexpensive prototype to throw on a car can save countless hours and headaches down the road. This is why we use 3D printers so extensively: it makes producing great parts for you all so much easier. Some of our manufacturers even use our 3D prints to help understand the part, help with quoting, and even use them for mold/jig making. At CorkSport, our 3D printers are used almost as much as our 10mm sockets!
I’ve just scratched the surface on 3D printers, their uses, and capabilities so, if you have any questions post it down below!
Mazda 3 Hybrid??
I was looking at the Mazda Japan website the other day and noticed that there is now an option for a Mazda 3 gasoline hybrid listed. Years ago Mazda announced that they were working with Toyota hybrid tech and this looks to be the result.
There isn’t a lot of detail listed with the description of the model so I decided to do a comparison of the Mazda 3 against the current model year of Prius as the 2 vehicles are most likely running the same hybrid drive setup.
Price: With the current exchange rate the Mazda 3 hybrid is ~$23500 which is almost the same as the current Prius price shown of $23475. You get more car with the Mazda 3 for the price and a car which handles like a car should. Win here for the Mazda.
Styling: Right away I can tell you I prefer the styling of the Mazda 3 over the Batmobile inspired Prius which looks like someone used a late 50s Chevy and applied the styling.
Fuel Economy: This one is the funniest thing and really shows where Mazda’s engine tech is beating all of the other manufacturers. Toyota Prius 1.8 hybrid gets 56mpg in combined city/highway. Mazda 3 2.0 hybrid gets 63mpg. Caveat on this data, I took the economy listed on the Japanese page and converted it to MPG so they are not based on the same drive cycles.
If your Japanese skills are on point check out the landing page for the 2018 Mazda 3 Hybrid yourself here. Just a note google translate won’t let you convert the page due to SSL from Mazda’s page.
So you are asking why do I care about a hybrid and in all honesty I probably won’t own one myself but if it does happen I prefer to at least own one that handles worth a crap and has decent driving dynamics. I can’t say I have ever heard anyone raving about how good the chassis is in a Prius.