Mazdaspeed Turbo – Choose Your Boost

May of 2015, CorkSport launched its first high performance drop-in turbocharger for the Mazdaspeed platform.  Fast-forward almost 4 years and CorkSport again is about to redefine what a stock flange turbocharger for the Mazdaspeed platform can truly be.  

The original “CS Turbo” is now the CST4 to follow the turbo line-up that is soon to launch.  The CST4 took a fresh approach to “big turbo” with all the included hardware, gaskets, and of course direct drop-in fitment.  It removed the guess work for a quick and easy installation, but the benefits didn’t stop there. This “little big turbo” packs a punch for its compact TD05H-18G wheels.  

With the CST5 and CST6 just around the horizon it would be easy to forget about the tried and true CST4, but don’t worry this Mazdaspeed Drop-In Turbo got some new love also.  You will now have a EWG housing option for the CST4. You can pick it up in EWG setup from the start or if you already have a CST4 that you love, you can get the EWG housing kit to do the upgrade yourself.

Moving onto the CST5 & CST6 the possibilities for the MZR DISI have moved up significantly.  What started as a single “bigger big turbo” has morphed into two “bigger big turbos” that, we feel, better provide for the various power goals of the community.  

We present to you the CST5

The CST5 bridges the gap between drop-in performance and big turbo power.  The journal bearing CHRA uses a hybrid TF06-GTX71 wheel setup that provides more top-end than the CST4 with minimal spool and response penalty.  Upping the big turbo feel is a 4in anti-surge compressor inlet which will require an up-sized intake system.

Unlike the CST6, the CST5 will be offered in both internally waste-gated and externally waste-gated setups.  This provides you with the flexibility to setup your Mazdaspeed just how you see fit and both have been proven 520+whp on our in-house dyno and tuning courtesy of Will Dawson @ Purple Drank Tuning.

Now… We present to you the Stock Flange Record holder…the CST6

Image: Mazdaspeed-6-big-turbo

The CST6 redefines what the community thought was possible from the stock turbine housing flange, but first some details.  The ceramic ball bearing CHRA uses a GTX3576r wheel setup that clearly out powers the CST4 & CST5, but that’s point remember?  

The CST6 is a legit big turbo, spool will be later, but still sub 3900rpm for full boost, however a turbo setup like the CST6 is not intended for low-end response.  If top-end power is your goal, the CST6 will deliver. In-house testing has pushed the CST6 to 633whp at a fuel limited ~33psi and 7900rpm redline.

Unlike the CST4 & CST5, the CST6 will only be offered in EWG setup.

In the coming months, we will be sharing more information about the CorkSport Turbo Line-Up; the design, the testing, and validation of each.  For more information about the CST5 & CST6 along with the new EWG turbine housing option, check out these sneak peek pages.  

Thanks for tuning in with CorkSport Mazda Performance.

-Barett @ CS

MZR DISI Injector Seals – The Correct Seal for YOUR Speed

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.

Injector Seals Design Part 1

Injector Seals Design Part 2

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

Turbo Inlet Pipe Differences

There are some significant differences about how we designed our turbo inlet pipe compared to the other solutions offered for the DISI engine. We get a couple common questions that we thought would be worth reviewing for our readers about our design vs. the other options on the market today.

The first question we get asked most often is also the most obvious difference, which is why we chose metal over silicone. CorkSport uses a mandrel bent aluminum pipe to replace the factory plastic pipe instead of silicone. The reason we chose metal in place of silicone is to maintain a better flow through a very tight area. Metal cannot distort in shape or size and provides a smooth pipe to flow through that does not have the rougher characteristics associated with the nylon braid used in silicone.

The second question that comes up most frequently is, can a metal turbo inlet pipe transfer heat to the air rushing through the pipe at a rate that would increase the temperature of the air going into the motor? To begin with, the pipe itself is insulated from touching the turbo or block by silicone so the actual heat transferred into it is very low. It is insulated from the bracket that it bolts to by rubber and has no other contact with the engine bay other than through the air. The physical air in the engine bay should be the same no matter what intake you run so the turbo inlet pipe will eventually reach the same temperature.

In order to test this we ran our test car on the same day with less than 10 degrees difference between ambient air temp between tests. We put the car on the dyno and ran the car at the same load from the same rpm range at 20psi. This was about 2500 to 6500rpms. The above graph shows the difference between intake air temp and boost air temp. The intake air temp is basically outside air temp and the boost air temp is the temperature of the air entering the engine. There was basically no difference from metal to plastic telling us that the metal is not able to transfer heat any faster than the plastic to the actual air traveling into the motor.

Bottom line, during testing, the CorkSport Turbo Inlet Pipe showed a 14% improvement in flow over the stock turbo inlet pipe, resulting in improved boost levels, and customers can rest easy knowing that the aluminum piping will not affect the temperature of the air running to the motor

Brydon-