I haven’t written any blogs in a while as there hasn’t honestly been anything from Mazda, which has made me stop and go WOW. Most people who have interactions with me would have thought I would be interested in the Mazda 3 TCR. The TCR car looks great, but when I learned Mazda went with the “Spec” engine for the series, it became a “meh” for me. Having an engine that is based on more or less a VW power plant pulling a Mazda around the track made it a lot less interesting. I do know why Mazda chose to go that path, but that is another story.
What did make me go WOW recently was at the Grand Turismo Championships when Mazda announced the RX-Vision GT3 concept! Mazda loves a sexy race car, and if you look at the past two, they have both come out of the Mazda North American studios. This concept is no exception as Julien Montousse, the design chief for Mazda North America, was present during the announcement of the car.
This is a big deal in my mind, we have just seen a change at Mazda USA with Nelson Cosgrove now appointed as the new director of Mazda Motorsports. Mazda has done everything except come right out and say we are going to build another rotary, and that message looks to be getting stronger. We have seen more patents popping up, calling out more tech and drawings of rotary goodness, including my favorite the top-mounted turbo rotary engine from years back.
Like anything Mazda teases us with, we will have to wait and see what happens. On a personal level, I hope Mazda gets us a 2020 Mazda 3 AWD turbo MT, but that is another one of those “wait and see” dreams from Mazda.
Hey Everyone, if you don’t know me already I’m the engineering manager at CorkSport Performance & @Halfmilespeed3. I want to make a formal greeting and invite you to follow along as I take the next huge step with my personal build. I drive a 2009 Mazdaspeed 3 that has been through many iterations. I bought it nearly 6 years ago and have since used it in excess to support CorkSport R&D. Hundreds if not thousands of passes on the dyno with so many parts…it’s been a beaten test mule. The time has come to set a focus.
Now, with the 4th engine going in it, I’m setting the build focus for ½ Mile Drag Racing. Power, Aero, and some “Mad Scientist” R&D is going into this build. (see WTF is THAT)
My goals are 700whp on the CST6 stock flange (with Will @ PD Tuning giving it the sauce) and 180mph in the standing ½ mile. I plan to play in the 1320, but half mile is the focus. My first event was going to be Never Lift @ Coalinga Munical Airport in Late March, but with recent events, this was canceled and a new date has not been set. Fingers crossed the country gets through this and the next events hosted by Shift S3ctor Airstrip Attack in June and November hold.
Back to the build…I know that pushing a Mazdaspeed through the air at 180mph is a lofty goal and that physics are against me. With the help and advice of Aaron O’neal @ English Racing I am exploring high-speed aero design.
The primary goal is stability at high speed. I want to be safe in this type of racing so I need to do what I can to make the car stable and predictable at speed. This means I need the car to cut through the air as smoothly as possible, and if possible, generate downforce.
To do this I’ve made a prototype drag wing (which I will share more detail on in a later blog) per the advice of Aaron and my research. This wing is two feet long at the top! And with the closed sides, this should reduce the amount of lift generated at the back of the car.
There is still a lot more work to do here but you get the idea so far.
Upfront I am still very much in the conceptual phase of design. Nearly the whole front bumper will be sealed off with a single sheet of ABS plastic formed to the front of the car. The only opening will be a rectangle about the size of the intercooler for cooling airflow. I also plan to build a chassis mounted splitter. The red parts in the image above are the one-off brackets I designed to mount the splitter to the chassis and still be able to adjust the height (Again I’ll share more detail in future blogs as the prototype comes together).
The other less intuitive aero bit I’m doing on the front of the Speed is hood venting. Thanks to Jonathan Castro @ JC Speedworks for the hood vent I’m able to kill two birds with one stone here. If you’ve done any type of racing you know heat is a killer and must be managed. With this hood vent, I am both evacuating any high-pressure air build up in the engine bay and promoting more efficient airflow through the intercooler and radiator.
With the 300 miles I’ve put on the car, I can already see a huge difference in normal operating temps. Maybe more vents are in the works? 😉 Oh and shout out to @mz_rawr (Aaron Maves) for cutting holes in my hood.
In the process of getting the engine and transmission together, I wanted to fix a 2nd gear drop out issue I had. Over a weekend @thatonepnwguy (Bryce Peterson) and I split my transmission and replaced the shift forks. We certainly did it the wrong way and had to chase some balls around and get them back into their respective locations; despite all that, don’t be afraid to tear into things and learn the hard way.
The powerplant made it in the car and is running great. Right now I’ve got about 300 miles on the engine. I’ve been working out some little details with heat management and setup of the Vacuum Pump (WTF is THAT). I am just now starting to do logs and tuning with Will Dawson at Purple Drank Tuning. With these goals, I still intend to keep the car street legal and driven on a nearly daily basis (I wish you could see the stares I get from people). I’m putting this out to all of you as an invite to follow along with the build on Instagram @halfmilespeed3. All the inside info and goodies are there for you to see along with @corksport for other stories and build updates. I’m stoked for this season and to explore a racing series that has largely been untouched by the Mazdaspeed community. I will be finding limits and new challenges for the platform that I hope to overcome.
Barett’s 1/2 Mile Mazdaspeed 3 Build – Part 1 May 7th, 2020CorkSport
We are proud to announce a old product that we have redesigned. Introducing the V2 CorkSport Coilovers for 2004-2013 Mazda 3 and Mazdaspeed 3.
We’ve taken the same basic designed and revised and refined it with small changes to fitment and big changes to spring rates and damping rates.
For spring rates we took an approach that seems to differ with most street oriented kits on the market today. We wanted to develop coilovers that were both enjoyable to drive on the street in a daily driven car, but could also perform on the track in more performance oriented settings. With these goals we focus on the ride feedback, understeer/oversteer balance, and suspension frequency balance.
The result; linear rate 7K front springs and 8.5K rear springs. This provided us with a ride quality that was comfortable, but sport focused and with the right balance of understeer vs oversteer, with a car that is more oversteer biased. The frequency of the suspension was also taken into consideration with a higher rear frequency than front to improve driver feedback and comfort.
Like most coilovers, ride height adjustability is essential to setting up you Mazdaspeed 3 or Mazda 3 for your goals. The redesigned CS coilovers offer 2 inches of height adjustability from approximately 0.75 inches to 2.75 inches lower than stock springs. This range of ride height allows you to have a conservative track-oriented setup or a slammed show setup depending on your goals.
With ride height, you can also adjust the front camber setup with the CS Coilovers include front camber plate, this kit comes to your door ready to install.
Lastly, and also somewhat unique to CS, is the design of the front coilovers. Instead of a more conventional and cost effective design, we’ve utilized an inverted damper design for improve performance. By inverting the front damper/shock, we’ve both reduce the unsprung weight of the front suspension and increased the rigidity. Both of these result in increased driver feedback and improved performance.
If you been considering lowering springs or coilovers for you Mazda 3 or Mazdaspeed 3 then give CS a good look. Thanks for taking the time to checkout CS, stay connected on the blog, newsletter and social media channels for upcoming performance parts for your Mazda.
We’re back on the new CorkSport turbocharger lineup again with today’s blog, this time focusing on the testing & validation of the “medium big” turbo, the CST5. Just in case you missed it, the CST4 (formerly known as the CorkSport 18G) is getting some company to go along with its new swanky name. Check out the full lineup here and the design behind the CST5 here. Now that you’ve read all that, let’s get into what you’re really here for, testing & dyno numbers.
We started with the internal wastegate option, to validate the CST5 for drop-in fitment. Since we’ve had great experience with the drop-in CST4, we knew how to design a turbo around the tight confines of the Mazdaspeed engine bay. The CST5 fit great in the OEM location with just a few minor revisions for proper fitment. It looks pretty good in there too if we do say so ourselves!
Next the car got put on the dyno for tuning and to push the new CST5 to its limits. With a little help from our friend Will at PD Tuning, the CST5 was soon putting down some impressive numbers. We started off with a “calm” boost level of ~25psi. This netted us 450WHP and spool time that surprised us, achieving 20psi by 3500-3600RPM. Turning up the boost and pushing the turbo to its limits, we achieved 519WHP at ~30-31psi on Barett’s built GEN1 MS3. Check out the dyno graph below.
Taking the car out on the street surprised us further at just how early the car was building boost for this size of turbo. Road logs showed that we were making 20psi slightly sooner than on the dyno (3400-3500RPM) but even more surprisingly the CST5 was making 30psi by 3700-3800RPM! Obviously this is an aggressive tune that would most likely kill a stock block, but, the CST5 can be tuned to be stock block friendly and still make good power.
Then came the testing on the EWG variant of the CST5. We had developed fitment for the CST6 which meant the CST5 had no issues upon install on both MS3 and MS6. Next was a quick retune and some power runs. The larger swallowing capacity of the EWG housing meant some extra power at peak, yet spool was nearly unchanged. We made 525WHP at the same ~30-31psi.
Comparing the IWG and EWG turbine housings you can see a small variation in the graphs. This variation is mainly due to the change from internally waste-gated and externally waste-gated. The EWG setup provides more precise boost control through the RPM range. The EWG setup allows us to better tune the “torque spike” around 4200rpm vs the IWG setup. For peak power the IWG and EWG housings are within the margin of error which makes since because they are both 0.82 A/R housings.
Further supporting the IWG and EWG setups, both options allow you to tune the spring pressure so you can better setup your CST5 and Speed for the fuel and boost levels you want and of course the most noticeable difference is what you hear. What’s an EWG without a screamer pipe!
Wrapping up testing showed exactly what we were hoping for with the CST5: a great middle ground between the existing CST4 and the upcoming CST6 that can be used on both high powered stock block and fully built cars. Our testing continues as this blog is written as the CST5 is being beta tested by a close friend of CS with a freshly built Dankai 2.
There’s more to come from the new CorkSport turbo lineup so stay tuned for more info on the CST5, CST6, and EWG housings.
-Daniel @ CorkSport
CST5 Spools!! Testing and Validation February 28th, 2019CorkSport
The development and evolution of the CorkSport Performance CST5 and CST6 turbochargers are uniquely intertwined. We’ll be honest, we started with the goal of a single larger turbo than the CST4 in mind, but as development progressed we were not getting the exact results we wanted. We wanted fast spool & transient response, huge power, and to retain the internally wastegated system. Something had to give…we realized that we were asking too much from a single turbocharger, thus we redefined what we wanted and realized that two separate and focused turbochargers for the Mazdaspeed platform were the ideal choice.
Today we will focus on the design around the glorious CST5, specifically the theory and design around the wheel selection for the CST5 and why it works.
CST5 Wheel Design
The compressor wheel utilized on the CST5 is the well-known and trusted GEN1 GTX71. Compact and efficient, this compressor is rated for 56 lbs/min flow rate with a relatively high-pressure ratio threshold. Paired with a 4-inch anti-surge compressor housing and we have a very versatile and responsive compressor setup.
Now here is where the design begins to deviate from the standard path. The turbine wheel is an MHI TF06 design that is designed for high-performance applications. The TF06 turbine wheel is the key to the performance of the CST5. Let’s see how and why below.
If you are unsure of the turbine wheel size don’t worry, that will get covered shortly. For comparison, the MHI TF06 is very similar in size to the well-known GT30, but there are a few very specific differences that affect performance.
The first and most obvious difference is the number of turbine blades; this difference has a couple of benefits. First, less weight; even a small difference in weight can make a significant difference in the spool and transient response characteristics of the turbocharger. Second, reduce flow restriction; with one less blade, the “open” area through the turbine wheel exducer is increased which increases the peak flow potential for top-end power.
Inducer & Exducer
Next, are the less obvious differences. The GT30 has a 60mm inducer and 55mm exducer which equates to an 84trim turbine wheel vs the TF06 with a 61.5mm inducer and 54mm exducer which equates to a 77trim turbine wheel.
There are two key values to pull from this: First, the turbine wheel inducer directly relates to the peak flow of the wheel and the overall wheel size balance which we will cover next. Second, the turbine wheel trim affects the spool and response characteristics of the turbocharger. The smaller the wheels trim the faster the spool and response.
Alright here is the most important and commonly overlooked aspect of a turbocharger. There is a rule of thumb when sizing the compressor and turbine wheels for a turbocharger.
If the turbine is too large then the turbocharger will be very “lazy” and have trouble building boost.
If the turbine is too small then the compressor may be overpowering the turbine wheel causing excessive exhaust gas buildup that can rob power even though you may be running a very high boost pressure.
So what is the right balance? From our experience in turbocharger design, development and validation along with industry professionals we have consulted there is a rule of thumb we have found when sizing the compressor and turbine wheels. The exducer of the compressor wheel should be 10-15% larger than the inducer of the turbine wheel as shown in the image above.
So why does this work? Well, let’s look back a bit first. Many think you can just install a larger and/or higher flowing compressor wheel onto the turbocharger to make more power. Now that is true to a point, but quickly the approach becomes very inefficient for the engine. Forcing more air into the engine without improving the flow out of the engine can only go so far.
Everything that goes into the engine must come out, right? Increased A/R sizing and turbine wheel sizing is the key to exhausting all the gases from the engine efficiently, and efficiency is key to making power.
With both the CST5 and CST6 development we focused on the overall performance of the engine, not just the development of a high-performance turbocharger.
Thanks for tuning in with CorkSport Mazda Performance, more to come…
-Barett @ CS
Inside look: CorkSport Turbo Design June 26th, 2019CorkSport