Mazdaslow to Mazdaspeed

Let me take you to an extraordinarily dull time in my life, the last time I started my car when it was still stock.

September 14th, 2018 was a beautiful September day in Washington. I started my car at 6:45 am, just like every other weekday. The car burbled to life, but it was relatively quiet, flat, and a bit uninteresting. No one knew I was leaving for work – I wasn’t shaking any windows, but that was going to change.

At CorkSport

Once I arrived at work and spread some Friday cheer, I settled in. Almost immediately, I could feel the pile of parts in the corner behind my desk, glaring at the back of my head. I thought to myself, “Don’t turn around – focus damn it!” The day had finally come – install day. Thankfully with our awesome half-day Fridays, I was out of the office and on my way to Brett’s house before 12:30 pm. 

After we loaded up Brett’s Rodeo with a load of parts, we set sail to our destination, a place where many tears have been shed, knuckles have been busted, and where dreams have come true; Brett’s garage. Every tool you’ve ever needed and gadgets you didn’t know existed. There were even a few specialty items present, that if he didn’t have quite frankly, this couldn’t have happened.

Shop all Mazdaspeed 3 Parts

We started with thorough degreasing of the engine bay and setting up the essential supplies- because what is an install day without beer and snacks! Once the car has cooled down, I started with taking out the battery box, intake, and intercooler; and then the fun really started. I’ve read the horror stories, I’ve watched the videos, and I thought I spent enough time mentally preparing myself for what was about to come – I was wrong.

The Downpipe

We all know about the Mazdaspeed downpipe on our cars. The devil engineered the placement of this thing, and he had his minions tighten the bolts. There isn’t enough PB blaster in the world to help the corrosion and excessive heat that these bolts withstand. We got the first one out with little to no issue, but it just got progressively harder from there. It was only a matter of time before rounding off the edges of that last bolt. Thankfully Brett has an extractor tool that we hammered on there, and with the small act of god, it was successfully extracted.

My experience with removing the downpipe from the exhaust, as is everyone’s experience, was different. Mine was influenced by the previous owner adding a 2.5″ resonated exhaust on it from the second cat back. The downpipe didn’t want to come out until I wiggled a pry bar in between the flange and put Brett’s Caliper spreader in there (again tools I didn’t even know I needed) and applied sheer grunt force. I got the flange to bend, and after learning a few new choice words, we got it out. By this time, it was 11:30 pm, and we still had a few other things to unbolt before the exhaust came out. Instead of using power tools and waking every neighbor up in a two-block radius, we called it a night.

The Morning After

After some much-needed coffee, we made it back from the hardware store (replaced the downpipe nut from hell) it’s time to party. We started with sliding in my new downpipe with the High flow Cat what a breeze compared to taking it out. Next came my intake, I went with the 3.5″ so I don’t have to buy another one when I finally go with our CorkSport CST4 turbo. Still might go with the new CST5. Then I put in my ECU Relocation Box, and I have to say, what a clean looking piece to have in your engine bay! 

Mazdaspeed 3 TMIC Top Mount Intercooler

We changed out the OEM spark plugs for some NGK 6510 gapped to .026 and started to put on my new TMIC that is rated up to 450WHP after we got the TMIC it was time to put on my shiny new boost tubes Engine bay= Complete.

Now time to get underneath and put on my highly anticipated Non-Resonated Cat-Back exhaust and my Stage II RMM. Goodbye, torque steer! Once we had the exhaust mostly in place, I realized if I didn’t have the CS exhaust hangers I would have been in trouble. The person before me had his exhaust welded quite poorly in place of the hangers, and I didn’t have an option to use my OEM ones. 

Moment of Truth

After everything was double-checked and rechecked, it was time for the moment of truth. I hooked up my battery, I flashed my new tune from Erik Bjork at Drama Tune, and now it was Go Time! I will say hearing my car make those sweet sounds was one of the best moments of my life. I’ve been waiting for this moment since I purchased my car, and it was one of the most surreal experiences I have ever had.

We let the car run for a few minutes and checked to make sure I didn’t have any leaks, and then we headed out for a test drive.

In the immortal words of George Takei “Oh My!”

That was my thought, EVEN on just a base map. My car felt and sounded 1000% different than before. The intake was amplifying fun new mechanical noises – like I was hearing my turbo and BOV dance for the first time. The crackle from the exhaust on a hard 2nd to 3rd upshift was intoxicating, all the while my RMM putting in work to make sure I don’t torque steer into someone’s front lawn. What an experience! I would even call this life-changing for me. The funny part of the story is that I wasn’t planning on buying all these items at once – true intentions of a foolish car enthusiast. Thankfully for me, I have a fantastic career within CorkSport and have a great friend that helped me make my dreams come true. Who wants a stock car when you work for the number one place in the world for Mazda Performance, not this guy.

Zach from CorkSport

Keep an eye out for my turbo blog, because it’s only a matter of time until the mod bug bites me again.

SkyActiv 2.5T Cold Side Boost Tube Part 2: Testing

In case you missed it, we have been working on improving the flimsy rubber tube that comes stock on the cold side of your 2018+ Mazda 6 2.5T. Check out the first part on the cold side boost tube here and the full OEM piping & intercooler breakdown here. Since our last installment, we have been busy testing a prototype CorkSport Boost Tube and would like to share some results with you all.

Testing Results

SkyActiv 2.5T Boost Tube
CorkSport SkyActiv 2.5T Boost Tube

Starting off we tested and data logged both the OEM tube and CorkSport Performance Boost Tube on the dyno. We were not expecting to see too much of a difference to power with just the boost tube changing however, we did see tiny improvements here and there, most notably way up at the top of the RPM range.

Check out the graph below, (OEM: red, CS: green). We tested on the same day in identical conditions and the car had a CorkSport Intake and Cat Back Exhaust installed for both tests.

PLEASE NOTE: the variations below 2800RPM are due to inconsistencies associated with dyno testing an automatic car.

SkyActiv 2.5T Boost Tube Performance Dyno

After noticing these changes, we went to the data logs to see how the boost changed between the OEM tube and the CS Boost Tube. The graph below shows the engine RPM versus the manifold pressure in psi. Both lines have the same smoothing done to the raw data. As you can see, the CorkSport tube (green) holds about 0.5psi through the midrange (3500-5000RPM) and is almost 1psi more when above 5500RPM. This correlates well with what we saw while dyno testing.

SkyActiv 2.5T Boost Tube Manifold Pressure Test

Testing the Changes

The small increase in boost pressure is likely due to the CorkSport tube not expanding as much when under pressure. To confirm this, we capped off both ends and pressurized the each tube to 20psi. Note: do not try this at home as the caps can easily fly off and injure you.

Boost Tube being tested

After measuring multiple locations both before and during pressurization, we found that the OEM tube expands about 12% in internal cross-sectional area while the CorkSport Boost Tube expands 3x less at 4%. Keep in mind that this would be an even larger difference if the same test was performed with the tubes installed on the car due to the heat of the engine bay. Since silicone is more stable than rubber at high temperatures, the heat of the engine bay will not soften it nearly as much as the rubber OEM boost tube. A softer rubber tube would mean even more expansion when pressurized and even more inconsistent boost pressures.

CorkSport and OEM Boost Tube Comparison
CorkSport Boost Tube (left) & OEM Boost Tube (right)

This data may not show drastic changes but it does not tell the whole story. The larger diameter and thus larger volume of boosted air of the CS tube provides a little bit better response when low in the RPM range. While this may just be a placebo effect on our end, there’s not too much of a wait before you can try it yourself! Stay tuned for more information. If you want a more serious upgrade though, keep your eyes out for information on the upcoming CorkSport FMIC kit and Piping Upgrade kit!

P.S. 2016+ Mazda CX-9 owners and future Mazda CX-5 2.5T owners, don’t worry we will be checking this for fitment along with other CS goodies!

-Daniel @ CorkSport

2018 Mazda 6 Performance Parts – Cold Side Boost Tube

You have probably heard us mention the new Turbocharger Mazda 6 in the recent weeks and months and have probably been wondering; “what’s going on?”  Well, today we’d like to share a little bit about what’s been going on at CorkSport HQ with our very own 2018 Mazda 6.

Right off the bat, I can say we have a handful of exciting performance products in the works and will be sharing info on them as we make progress.  Today we want to talk about the intercooler piping, specifically the cold side piping and the parts of the system. This is the piping that connects the outlet of the intercooler and the throttle body.  It is commonly referenced as the “cold side piping” because the charge (boosted) air has passed through the intercooler and is therefore cooler.

The OE cold side piping consists of three main components.  Starting on the right side of the image; we have the hard piping that connects to the intercooler and a soft rubber hose.  Next is the soft rubber hose itself, which we will talk more about later. Lastly is the throttle body connection, which is the oddest part of this system.  You can see why in the next image.

The above-mentioned intercooler hard pipe and the rubber hose are pretty common parts on modern turbocharged vehicles, but the throttle body connection is unusual from our experience.  The throttle body connection appears to be designed for a quick connection (and not so quick disconnection) during the vehicle assembly process. Unfortunately, this leaves a very odd connection flange on the throttle body itself.  Lastly are the fins inside the connection part; other than straightening the airflow entering the throttle body we don’t see many purposes these. We will be testing the effects and need for these in the near future.

Now let’s get to what we really wanted to talk about; BIG Silicone Performance Parts.

Mazda designed the Turbocharged 2.5L SkyActiv-G to function at a specified boost pressure and no more.  However, we fully intend to change this set boost pressure for increased smiles per gallon. With increased boost pressure comes more force and strain on the OE rubber hose.  Eventually, the OE rubber hose becomes too flimsy for the increased boost pressure and may expand or fail completely via a rupture.

So how do we develop a performance part to replace a rubber hose?  Well, there is one obvious improvement and another not-so-obvious change that can be made.  First, we use silicone as the prominent material for its excellent heat resistance and durability.  Next, the silicone is reinforced with five layers of fabric braiding to withstand the increased boost pressures.  Compare this to the OE single layer of reinforcement and you can see why this would make a big difference.

Now for the less obvious performance improvement; the CorkSport 3D Printed prototype is larger in diameter than the OE rubber hose.  Leaning on our experience with past intercooler piping development, we have found that increasing the charge air volume directly in front of the throttle body increases throttle response and helps spool the turbo faster, reducing turbo lag.  

Currently, we are still in the development phase but will be testing soon.  Stay tuned for future updates on the CorkSport Performance Boost Tube and other exciting products for your 2018 Mazda 6.  

-Barett @ CS