Testing – CorkSport External Wastegate Housing for Mazdaspeed

Turbo EWG

Why EWG?  (it’s just about awesome turbo noises)

We hear this alot as the Mazdaspeed platform continues to grow and the 450-500whp build becomes the status quo. Following up the EWG Housing Design & Details Blog about the new CorkSport EWG Housing, we want to share some testing data and differences we saw between an IWG (internal wastegate) and EWG (external wastegate) setups.  

Details about design, flow, placement, data, and feedback from our CST4 EWG Beta Tester.  

IWG vs EWG comparison on the CST4
IWG vs. EWG on the CST4

Let’s jump right in!  First up is a spring pressure comparison between the IWG and EWG housing on a CST4 turbocharger.  Let’s first define what “spring” pressure is: this is the resulting boost pressure with 0 added wastegate duty cycle.  AKA we are not trying to add boost pressure.

Immediately you can see some very obvious differences.   The IWG setup has a taper up boost curve that could be considered boost creep.  Some boost creep is ok, but an excessive amount may reach the capacity of the fuel system or other systems in the vehicle.  In this setup that is not the case, but it does show that the IWG is at its limits for boost control.

With the EWG setup you see a much different curve.  The boost builds a few hundred RPM later (due to the larger 0.82 A/R) then climbs right to the spring pressure and then settles to a consistent plateau; very predictable and controllable.  

CAD EWG and IWG Designs
CorkSport EWG and IWG Designs

Now let’s look at the design to better understand why.  On the left is the EWG turbine housing with a 0.82 A/R and on the right is the IWG turbine housing also with a 0.82 A/R (we don’t want the A/R to be a factor in this review).   

The EWG housing has a very efficient flow path for the exhaust gas to reach the EWG control valve along with a much larger path to flow.  Both of these features provide excellent flow and thus control of boost pressure.

The IWG housing uses a side port in the turbine scroll to exhaust gas.  In this setup, the exhaust gas must make an abrupt turn and pass through a much smaller port.  Both of these issues reduce boost control.

EWG and IWG Explained

Here is a diagram showing placement of an EWG in the exhaust pre-turbine.  Granted we are comparing a EWG and IWG, but the concept of flow is the same.  

Exhaust gases will always take the path of least resistance and if the turbine wheel is the easier path than the wastegate then boost control will be more difficult.  

Internal and External Wastegate performance chart
(Left) Internal Wastegate Setup | Common Issues
(Right) External Wastegate Setup | Optimized Setup
Click to Expand

This graph was shown in the last blog, but we want to show it again so you can directly compare it to the data graph below.  

Below is the boost curves for the CST5 in both IWG and EWG setup.  Alone each graph actually looks really good, but when overlaid you can see some interesting differences.  

CST5 Dyno testing with IWG and EQG setup

IWG vs. EWG on the CST5

The purple IWG graph has a crisp spool and then flat-lines at approximately 30psi with a slight fall off at 6500rpm.  The CST5 IWG setup does control boost really well, but holding the turbo back at spool up and not over-boosting or spiking was a small challenge.  An abrupt boost curve like this can make the car somewhat difficult to drive because the torque “hits” very hard and you lose traction.

The EWG setup was a bit more controllable.  Not only did the CST5 turbo spool a bit sooner, but we were able to better control the spool up boost curve so we could create a torque curve that was more friendly to the FWD traction.  This makes the car more fun to drive. Looking at the higher RPM range we were also able to hold boost more consistently to 7500rpm.

CorkSport External Wastegate

We hope you guys and gals are as excited for the EWG options for the CST4, CST5 and CST6.  They really are an awesome setup for any driving style and power goal.  

Thanks for tuning in with CorkSport Performance.

-Barett @ CorkSport

CorkSport Injector Puller

For the Mazdaspeed 3, Mazdaspeed 6 & CX7

After years of popular requests, we have something that we are very excited to announce! The CorkSport Injector Puller is here, and ready to assist you with your DIY, or shop needs.

With great power, comes great responsibility! And owning a Mazdaspeed may have made you aware by now of how troublesome removing a GDI injector can be. We designed this to assist you.

YOU CAN NOW SAY GOODBYE TO:
  • Twisting a seized injector until it breaks loose
  • Rigging up some method to pull or pry out the injector
  • Beat up hands
  • Beat up injectors
  • Hours of lost time

Now, I know what you are thinking: we may be late to the party. We are aware that we are not the first ones to make such a tool, however, we wanted to ensure that we made one of the highest quality that can be used time and time again. We love that you guys buy our seals, and we wanted to help ease the installation as much as possible.

With its stainless construction, Nator can truly make use of this when it gets passed around, because it won’t deteriorate with use.

As the OE seals fail, carbon starts to built up around the injector and seal and really locks that sucker in there over time. Sometimes an injector has to be sacrificed as seen above. But, It’s amazing how much easier the proper tool can make the job.

Although it may resemble a shake weight a bit, its just your normal slide hammer style tool with a custom head designed to perfeclty fit the DISI Injector.

HOW TO USE:

  1. Take off O-Rings that will be on the tip of the Injector where it goes into the Fuel Rail. Be sure to store those in a safe place.
  2. Slide the head of the tool into position as shown.
  3. You will then put tension on the tool pulling backwards.
  4. Use your other hand to slide the hammer backwards until it hits the lock nut on the back. Repeat until the stubborn injector finally breaks free.

– The CorkSport Team

Be sure to check out our full product video on YouTube and remember to subscribe!

 

CorkSport BIG Turbo

Mazdaspeed 3 big turbo upgrade

Good day boosted enthusiast!

We wanted to take some time to give you all a quick update on one of the many projects we have brewing up here at CorkSport Headquarters.

The project I’m referencing, in general, is our 2nd turbocharger upgrade for the Mazdaspeed 3, Mazdaspeed 6 and CX-7. This unit is a substantial upgrade over our current 18G turbocharger. This Turbo will cater to those looking to take their performance and power goals to a higher level.

Not only will it be capable of putting you well into the 465whp range but this CorkSport Turbo upgrade will be able to do it without giving up on reliability and throttle response.  

It will be very beneficial to those who have mildly-built blocks and a supporting fuel system that will allow them to get higher in the HP range.

So, let’s talk about some of the features you can expect on the upgrade and why we decided to utilize them.

 

 

Let’s start at the heart of the Turbocharger.

The new CorkSport turbo will take full use of a GTX3076R center housing and rotating assembly (CHRA). The unit is equipped with a fully sealed ball bearing cartridge, which is a nice upgrade when compared to a standard journal bearing unit. We chose to go with a ball bearing unit for a few reasons.

  1. The enclosed design of a ball bearing system allows us to eliminate the need for a thrust bearing, which can account for about 40% of the bearing system drag on the turbos rotor assembly.
  2. Ball bearings reduce the viscous drag, which allows a ball bearing unit the ability to spool up about 15% faster than its journal bearing equivalent.

The next thing you will notice on the new Mazdaspeed Turbocharger upgrade is the holes that are drilled into the compressor cover. These little holes are known as anti-surge ports and are intended to expand the turbochargers compressor map. The ports function to move the surge line further left on the compressor map which gives the Mazdaspeed turbo some more headroom before it falls out of its efficiency island. Anti-surge ports are becoming increasingly more popular in modern performance turbochargers and with great reason. They offer some unique benefits as mentioned and will be fully integrated into our unit.

 

Last but not least, as with our CorkSport Turbo, this bigger Mazdaspeed Turbo will once-again be a true drop-in unit; minus the 4” compressor inlet.

There will be no cutting, modifying, sourcing oil and coolant lines, running to the store to buy couplers, etc. This unit will come with everything you need to have a trouble-free install. As with the current CorkSport 18G turbocharger, the new Garrett-based design will come with all studs, gaskets, washers, and knowledge that you need to have a nice weekend install.

So keep your eyes peeled as we get closer to delivering more performance for the Mazda community!

– The CorkSport Team

 

SOURCES: Miller, Jay K. Turbo: Real World High-Performance Turbocharger Systems. CarTech, 2008.

 

What’s in the Pipeline for the 2014+ Mazda3?

Here at CorkSport, we are always working toward the next new product. We create our catalog just like you build your cars. Since there’s so much in development, we thought we would give you all a glimpse into what’s coming for the 2014+ GEN3 Mazda 3.

2.5L SkyActiv-G Turbo Kit

Let’s start with the big one since you’ve all been asking for updates: the 2.5 Liter Skyactive Turbo Kit. We are still making steady progress and are more excited than ever for this Mazda3 Turbo. Our functional turbo kit prototypes are slowly starting to arrive, meaning we are inching closer and closer to having our Mazda3 test car on the dyno (with added turbo noises). Stay tuned folks; this is going to be a fun one!

2014-2016 Mazda 3/6/CX-5 Motor Mounts

 

We already showed you the new and improved CorkSport Rear Motor Mount, but there’s more to come with the CorkSport Transmission Motor Mount. Check out the CAD model above to see what we’re talking about. Keep tabs on the CS blog for more info on the design and function of this motor mount soon.

2014-2016 Mazda 3 Skid Tray

The CorkSport skid trays have been consistently requested for the Mazdaspeed models; so much, that we brought them back for both the Mazdaspeed3 and the Mazdaspeed6. Now we are providing the same benefits to Mazda3 owners. We just received and test fit our first prototype skidplate, and it’s looking very promising moving forward.

2014+ Mazda 3 Suspension Kit

Need some extra handling and style for your Mazda3 but don’t want the hassle of lowering springs? We have created a kit that includes the CorkSport lowering springs, adjustable shocks/struts, and camber plates all assembled with OE accessories and ready to install. No spring compressors needed, for ease of installation. Coming soon…

2014+ Mazda 3 Front Sway Bar

Reducing overall roll or “sway” can drastically change your Mazda’s handling characteristics. We should be receiving our first prototype to test fit on our Mazda3 any day now are excited to see how it complements the CorkSport rear sway bar. Oh, and the new front sway bar is 3-way adjustable just like our ND Miata sway bars!

2014-2016 Mazda 3 Steering Wheel

Last, but not least, our leather steering wheel will be making a comeback in the coming months. Featuring a similar profile to the CorkSport Mazdaspeed3 steering wheels, it is designed to increase confidence in both aggressive and daily driving while staying comfortable and stylish.

As you can see, we are staying busy with the newest generations of Mazda here at CorkSport, but that doesn’t mean it’s the only thing we are focused on.

We still have plenty of upcoming products for you Mazdaspeed guys and gals, and for some platforms you may not be expecting. Keep tabs on the CS blog, Instagram and Facebook page to make sure you don’t miss anything!

Until next time,

-Daniel @ CorkSport

The Mazda 3 Rear Motor Mount 2.0: Back & Better

2014 Mazda 3 rear engine mount upgrade

We here at CorkSport are proud to announce the relaunch of the Mazda 3 Rear Motor Mount.

Yes, you read that correct, this is a re-launch. At CorkSport we push ourselves to design and develop new and interesting products every day, with that, we try new and innovative manufacturing designs and methods in an attempt to create exceptional, competitive, cost-effective products for our loyal customers.

Sometimes those new and innovative manufacturing methods end up not being as awesome as we originally expected. This is just part of the designing and learning process. Let’s get into the details.

The original, let’s call it V1, Mazda3 RMM used a new-to-us manufacturing method of applying the polyurethane to the billet aluminum body called vulcanizing. The billet aluminum body and the steel sleeves are mounted in a fixture then liquid polyurethane was poured into the assembly and cooled until the polyurethane had set to the final hardness.  This process appeared to be very promising; each part was set up identically, it was nearly impossible to have any missing parts not sent to you, and most importantly the polyurethane was adhered to the billet aluminum body and therefore could not fall out.  More on that last bit later.

We moved forward with the manufacturing method and had a few samples made with various polyurethane durometers ranging from 60A to 80A.  After various testing, we determined that 70A was the best compromise of response and NVH (Noise, Vibration, Harshness) experienced by the driver. We continued testing for a few months to verify long-term durability and found no issues.  Hooray! We moved forward with production to get this new great Mazda6 RMM out the door to you.

Unfortunately, it appears that our testing period just wasn’t quite long enough.  Eventually, the polyurethane would fail but fail in a style we had never experienced before.  Long story short, polyurethane has excellent compression strength compared to the tensile strength.  The polyurethane was being pulled/split apart due to the forces of the engine.  

Now we had a few options of how to redesign the Mazda 6 Rear Motor Mount after going through the failure analysis.  

  • We could have simply stuck with the same design and just increased the stiffness of the polyurethane.  Increasing the durometer rating of the poly increases the tensile strength, but this would have resulted in an unsatisfactory driving experience for you which was unacceptable.  
  • The other option was to start from scratch again to create a new design that did not compromise the driving experience or the durability; with challenge comes innovation.

Again we went through many different designs, with the greatest challenge coming in the form of retaining the polyurethane pucks.  Typically the polyurethane pucks are retained by whatever the mount is bolting to, but with the Mazda motor mount, the steel sleeves extend far past the outer edge of the polyurethane pucks.  This leaves the pucks free to slide out of the billet aluminum body and cause a major failure.  

Using the conventional polyurethane puck style, we developed a design that would work, but more than doubled the number of parts needed which increased the chance for something to go wrong and drives up the cost.  This design is shown below:

 

The red arrows show the direction the conventional polyurethane puck would slide out of the body.  The red circles show the puck retention system to hold the washer and pucks in the body.  This retention design required many parts to be successful.

With the cost going through the roof we had to go back to the drawing board. There had to be a better way… and there was.  

The third major iteration shown above solved the problems of the V2 design and got us away from the vulcanized polyurethane of the V1 design.  Things were looking good.  With the V3 design, the polyurethane pucks are pressed into the billet aluminum body.  The pucks have ribs, shown with the red circles that are just large enough to keep the puck in place, but small enough to let the puck be pressed into the body.  

With this, we were able to make some clever designs to the RMM to keep it centered in the engine and chassis brackets on the vehicle.  The smaller diameter puck extends out to the ends of the steel sleeves; this keeps the entire rear motor mount centered.  The large diameter puck retains itself in the body and allows the associated steel sleeve free to slide for easy installation; shown with the red arrows.

Now… does it work? YES! Pretty fantastically, we might add!  

We have had this design on a handful of vehicles, one of those being the CorkSport Mazda 3 Racecar during the SCCA Run-Offs at Indianapolis Speedway.  Other than some dirt and grime, the tested RMM looks great.  

You were probably expecting this blog to be all about the details and reasons you should buy this performance RMM for your Mazda 3, Mazda 6, or CX-5.  All those details can be found on our website, and I invite you to check them out.

What we really want to get across here is this:

First and foremost, we will always do the best we can to take care of you and your car if there is ever an issue or concern with your CorkSport part.  

Second, if you are a driving enthusiast, if you go driving for the sake of just driving, then you need this RMM in your life. It will completely change and improve your driving experience, plain and simple.  

-Barett, CS Engineering