With a shop full of enthusiastic car guys and gals we are in love with the look and sounds of the CorkSport Cat-Back Exhaust on that larger than life CX-9. Customers love the sound, especially when completed with our Skyactiv Turbo Intake, but a few requested a little bit less racecar rumble. As you’ve requested, here is the new CX-9 axle back exhaust.
We are here to give our Cx9 customer what they want which brings us to a new exhaust option for the Cx9 Turbo, an Axleback!
The Mazda CX-9 Axle Back exhaust setup is great because you are still getting the awesome 100mm double wall slant cut tips, the high flow 80mm stainless steel piping, and an exhaust note that will still capture your attention as well as the other Cx9 owners on the road.
The in-cab exhaust volume and tone are much more subtle than the catback exhaust setup. This is your family-friendly and wife-approved exhaust for the Mazda CX-9. This is the “bluetooth office friendly meeting” exhaust system which is mellow at cruise but throaty when you get into the boost.
You can have your cake and eat it too. Check out the product listing for full details.
We’ve talked a lot about external wastegates with our recent CST6 development but today we are happy to announce the standalone CorkSport External Wastegate Housings for the CST4 and CST5. Available right now as an update for your existing IWG CST4 or CST5, the CS EWG housings make it easy to get the best in boost control for your Mazdaspeed 3, Mazdaspeed 6, or Mazda CX-7 Turbo.
While the CST6 will only come with an EWG housing, the external wastegate (EWG for short) is a new concept for the CST4 and CST5. Both of these turbos originally hit the market with an internal wastegate (IWG) only option that has a small flapper valve on the inside of the turbine housing to let off excess exhaust gases. Instead, the CorkSport EWG housings use an offshoot from the turbine scroll that has a v-band flange on the end. This flange allows for the fitment of an external wastegate for improved boost control. To run an EWG on an original CST4 or CST5 previously, you needed an EWG capable exhaust manifold and some sort of block off for the IWG port.
The new CS EWG housings make running an EWG on your Mazdaspeed3 easier than ever. Each housing comes with the elbow and clamp needed for great fitment. We even offer a dump tube/screamer pipe that works for both MS3 and MS6 as an add-on option. If you pick up the screamer pipe to go with your housing, all you need to supply is the EWG itself.
We strongly recommend a Tial MV-R 44mm wastegate as all design work and testing used this specific wastegate. Other wastegates may require modification for use. The 44mm size is a great fit for the Mazdaspeed engines, whether you are running an upgraded turbo on the stock block or fully built one that you intend to push to the limits.
So why would you want an EWG? For starters, EWGs truly offer the best boost control setup for any turbocharged car. Because the wastegate is separate from the turbocharger itself, it is easier to place for optimum boost control, plus, the design of the actuator itself can be optimized. As a result you get a wastegate that hits boost targets more accurately and responds quicker to changes in boost. This means no more boost spikes right when the boost hits (a common problem with poor quality IWG setups), and a near-flat boost curve. The isolated actuator also makes for faster and easier spring changes should you need to service or change your wastegate preload. For more info on the design behind the CS EWG housing, check out the full blog HERE.
One of the best parts of EWG over IWG is the sounds that come with a screamer pipe! While only intended for off-road use, a screamer pipe dumps the exhaust from the EWG directly to the air. This allows for a fantastic noise during a WOT pull, that sounds truly unique. It’s not all just noise though, by venting the EWG to the atmosphere instead of venting the IWG in your downpipe, you are decreasing exhaust turbulence right after the turbine wheel, reducing backpressure. On very high horsepower setups, this often generates some extra power as the turbine housing can be used more efficiently. Check out the product video below for some great EWG sounds from Barett’s MS3.
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There’s one final benefit of the CS EWG housings: housing design itself. Without having the IWG in the way to worry about, we were able to do some optimizing on the scroll and A/R. For CST4 owners, this means an increase in A/R from 0.66 to 0.82. Typically an A/R change like this will cause a slight decrease in spool time but an increase in max power potential. CST5 owners have this 0.82 A/R even with the IWG setup but there’s another benefit: greater swallowing capacity. This refers to the amount of volume in the turbine scroll. By increasing the swallowing capacity the turbine can ingest air more efficiently at the peak, which is especially important if you have an upgraded exhaust manifold or high flowing head. After all, an engine is an air pump – what good is shoving more air in if you can’t get it out?
If you’re in the market for a change on your Mazdaspeed, check out the CorkSport EWG housings for the CST4 and CST5 turbochargers. Better boost control, a more efficient housing, and best of all, a great new sound. Be sure to check out the listing for even more images and don’t be shy to ask questions we’ll be happy to help!
Mazdaspeed EWGs Made Easy! October 31st, 2022Derrick Ambrose
Track Tested CorkSport Approved 3rd Gen Mazda 3 Parts – Leading the Pack.
The last race weekend I had available before the runoffs turned out to be pretty interesting.
Locally there are very few T4 (touring 4) class cars so I often find myself running with other class cars and this weekend was no exception at Portland International Raceway. I showed up for qualifying on Friday morning with a new part to test and a suspension setup with something I had not tried.
I looked over the entry list the day before, and there read a list of cars you would expect to clobber a Mazda 3 on the track. 3 Porsche 911s, a pair of V8 mustangs, an STL Miata and more.
To make sure I had a clear track for qualifying, I hustled to the pre-grid to make sure I was the first car out. Straight out of the pits, I went flat out to get some distance on the Porsches to be able to push the car for the entire time I was out qualifying. As I watched the lap timer in the Mazda 3, my times kept dropping lap after lap. 6 laps in and I had already bested my fastest lap time at Portland by a second, so I called it quits and pulled in to the pits.
On the way out of the track I grabbed the time sheet to review and see where I placed. A quick review of the sheet showed I had qualified the Mazda 3 in second out of 10 cars and I was in front of 2 of the Porsches.
The start of the race didn’t go that great. Out of all the cars on the track I was in the bottom ½ for horsepower. But I was making up the speed in the corners.
One of the back cars jumped the start a bit and managed to take us 3 wide into a corner which is only good for 2. I was forced to give up some room to one of the Porsches to keep from having contact which put me back to 4th. Several laps into the race one of the Porsches who got ahead of me at the start spun off the track so I was able to move back up a spot while trying to chase down the leader who was running ~1 second a lap faster than I was. The 30 minute mark came pretty quick, and the race ended on a not-so-exciting note of me being in 3rd, and the leaders ~ ½ a lap ahead and all but a few of the rest of the field being lapped.
The big question you all want to ask is: “What were you testing for the 3rd Gen Mazda 3?”
First things first, the changes we made to the Mazda 3:
We made an adjustment with the CorkSport rear adjustable swaybar. Being able to make quick adjustments on the rear swaybar bar allows us to soften the suspension to match the alignment changes.
We had taken more rear camber out of the back of the car with the CorkSport adjustable camber arms, trying to decrease rear grip (yes you read that right). We have been having problems with front end push (understeer) so we worked on dialing rear grip out of the car. – We had the CorkSport front camber plates maxed out for camber to the class limits, but it wasn’t enough to offset the rear grip.
We originally were running our CorkSport Mazda 3 adjustable shocks on the track but we had to remove them as they are not legal for the Touring 4 class. The adjustable shocks make a world of a difference over what I have to use on the car and I wish we could’ve changed back. Being able to fine tune the Mazda 3 suspension is a great asset for any performance driver.
Now to the fun, what I got to test that was new:
The engineers here at CorkSport have been working on a revised Mazda 3 Rear engine mount for the 3/6/Cx5 over the past few months. The best way we have to extreme test parts is on the track.
Think of the race-testing this way: I am driving full throttle, banging gears, and when I am off the throttle means I am on the brakes, so there is no time for the mount to get any rest. There is the maximum amount of heat, load, and stress in a compressed time line, compared to street driven cars, so if failure is to occur it would be on the track.
At the end of the month, I will be doing a test on a final version of the rear engine mount at the SCCA Runoffs and competing to bring home a National Championship for CorkSport and Mazda.
You just can’t beat the fact that our CorkSport parts walk the talk when pushed to the extreme, which means they won’t let you down, no matter what you’re doing.
Charge for the WIN!
Derrick
Charging for the WIN! January 30th, 2019Derrick Ambrose
Mazda hasn’t done anything to squash the rotary engine rumors flying around the possible new RX-9. In fact, as of a few days ago, an executive from Mazda confirmed in more or less words: Yes we are working on it, and it is moving along to a more advanced stage.
Let’s review what we have seen so far.
Hybrid Drive Train Patent dated September 2016
Mazda basically penned out a drivetrain setup for the next generation of Rotary vehicle. There was also a rotary specific i-stop type patent entered as well. The only problem is we have seen something contrary to this in the next topic which makes this puzzle interesting.
Rotary Turbo Patent dated August 2015
This patent got everyone (including myself) really excited. Top exhaust ports, a turbo mounted to the top, rear wheel drive, and it is screaming for a huge upgraded turbo to be sticking out of the hood….
One can dream right? I digress with that path but looking at this patent Mazda was working on a different variant of the engine and thought it was important enough to file a patent on it. It should be noted once again this patent was from 2014.
Dorr Support Structure January 2017
The last patent popped up recently and it suggests a lower slung sports car as it moves the door up at a 15% angle and uses a torsion rod to hold it open. The only use a car would have for this is if it is low and you don’t want to hit your doors on curbs when you open them.
Looking back further we can see other patents from Mazda which point towards the continued research of the next rotary with laser ignition, different configurations of the engine, the 16x, etc.
Recently at the Mazda tech forum in Germany, Mitsuo Hitomi from Mazda confirmed that the development is in the advanced stage.
It looks like Mazda is willing to say they are still working on it, but not willing to say, “Yes you will have an Rx-whatever on this specific date.”
Adding to the fire, several Japanese magazines have been saying the Tokyo Auto Show will have the next car at it as well.
With more and more pieces to the puzzle being revealed, perhaps this will be the year we get to see the next RX. My money is on the strategy that it will be teased much like the RX-Evolve and the RX-Vision were, and we will get a real car and one heck of a surprise at the Tokyo Auto Show.
A guy can dream right?!
-Derrick
RX-9 Rotary Engine Puzzle: Confirmed? February 21st, 2018Derrick Ambrose
