SkyActiv 2.5T: Let’s Talk Intercooler Pipe Upgrades

We recently went over the stock intercooler & piping system for the 2018+ Mazda 6 2.5T. If you missed it, be sure to check out the blog HERE.

Today, it’s the first look at the CorkSport parts that will be coming in the near future to remedy the issues we found with the OEM system. We are not covering our upgraded intercooler just yet though; today’s focus is piping upgrades!

As you can see we’ve been busy getting the upgraded intercooler piping designed & 3D printed for test fitting (while you can’t see it I promise the cold pipe is hanging out in there too!). I’m happy to say there’s plenty of room to fit the upgraded piping sizes that we were targeting and hopefully they will net us a few HP gain without any other changes.

These horsepower gains typically comes from removing sharp bends and diameter reductions in the stock piping that cause pressure losses. Then, the turbocharger can operate more efficiently to reach the desired boost level. Now how about some more detail on how and why each pipe has changed.

Starting off with the hot side of things (piping from turbo to intercooler), check out the CAD image above. As you can see, the OEM piping (left) is smaller than the CorkSport piping (right). In fact, we plan to use 2.25” piping for the hot side. Note that the plastic OEM piping is much thicker wall than the CS aluminum piping so even if the outer diameter looks similar, the inside diameter is much larger.

In addition, we keep this same inside diameter throughout while the OEM piping has a major diameter reduction through the middle. For those of you coming from a Mazdaspeed 3, 2.25” is the same size used on the hot side of all CS intercooler kits and has proven itself to support 600+WHP on Barett’s car (more info on that HERE). While we know the Sky-T may not be to that level just yet, 2.25” is a great size that gets the hot air to the intercooler as fast as possible while retaining high horsepower capabilities.

It’s not all about size though. Instead of using many tight radius direction changes like OEM, the CorkSport hot pipe uses smooth, large radius mandrel bends throughout. This means smoother and faster airflow to your intercooler. Lastly, you may notice the CS hot pipe is significantly longer than the OEM hard plastic unit (the OEM rubber tube starts at the connection point circled in the image above). This reduces the amount of flexible connector used, limiting what could expand at high boost levels. That being said, the CorkSport kit will use high strength silicone with four fabric reinforcement layers to prevent any expansion anyways.

The cold side of the system was already a decent diameter from the factory, but as you can see, we went even larger. The rubber OEM cold pipe will be replaced with a 3” diameter aluminum pipe. This large diameter pipe and huge volume of air that comes with it right before the throttle body has proven to help throttle response and reduce boost lag on our GEN2 Mazdaspeed 3 FMIC kit. We hope to get much of the same from the SkyActiv 2.5T. The cold side also uses large radius mandrel bends for smooth and fast airflow.

Lastly, the cold side piping reduces the amount of flexible connector used. And just like the hot side, each end of the pipe will use 4-ply reinforced silicone to prevent any expansion under high boost levels.

Those of you with a keen eye will have realized that our planned silicone connectors do not use the same connection style as the OEM intercooler. This is for good reason: we believe that the OEM intercooler will run out of cooling capacity before the OEM piping really becomes an issue. So a piping upgrade by itself wouldn’t show too much of a performance advantage.

In addition, we were able to design the piping to be the best it can without using the constraints of the OEM intercooler. So yes, the upcoming CorkSport intercooler upgrade will be required for the CS piping upgrade to work, but it’s so the CS piping & FMIC combo can be the best it can be for you all!

For those of you that have stuck around this long, check out this tease of a CAD model of the CorkSport FMIC & Piping kit.

And just because we like teasing you, check this early prototype out. Testing to come soon!

Stay tuned for more, as next time we will cover the intercooler itself. Also let us know your thoughts down below, we love your input!

-Daniel @ CorkSport

“Which intercooler should I get?”

“Which intercooler should I get?” At Corksport we get this question almost every day. The debate of top mount intercooler vs. front mount intercooler has been one that has raged on in the forums for years. Just looking around you will see both options on all sorts of cars. So what is the answer?

Mazdaspeed 3 Top Mount Intercooler

 

The Mazdaspeed 3 and Mazdaspeed 6 both come with top mount intercoolers (TMIC’s) from the factory. There are many reasons for this, but the main one is that it is much cheaper to manufacture and install. A Top Mount Intercooler can be installed directly to the engine at the factory so it is ready to drop into the car which saves both time and money.

Beside the TMIC, the other option available is the front mount intercooler (FMIC). Both styles have their pros and cons. The upsides of the TMIC is that it uses the shortest possible path from the turbo to the engine. This reduces the amount of time it takes for the car to accelerate, this feeling can be amplified between shifts when the power comes back on very quickly. The TMIC also is very simple and compact with very few connections and possible places to leak. A TMIC will also weigh very little compared to a FMIC setup and usually is in a place with very good airflow.

 

CorkSport-Intercooler-Mazda-Mazdaspeed-3-Front-Mount-vs-Top-Mount-2

 

The downside of TMIC’s is that they are generally limited in size by the design of the car and can be much smaller than most FMIC’s. They are typically placed very high in the engine bay, raising the car’s center of gravity. Most importantly though, the biggest downside of the TMIC is that it sits in a hot engine bay. Just by sitting on top of the motor, the TMIC can soak up heat thereby decreasing its effectiveness in cooling the air compressed by your turbo.

 

CorkSport-Intercooler-Mazda-Mazdaspeed-3-Front-Mount-vs-Top-Mount

 

The principals are mostly the same for the pros and cons of the FMIC. The core of a FMIC can be much larger, and in the case of a properly designed system, can cool temperatures much more effectively. Being placed further away from the engine and out into the stream of air can make the FMIC much cooler and more importantly, more consistent. One last reason that many people love FMIC’s is the look, nothing says I mean business more than a massive bar and plate core smiling in your rear view.

The biggest downside of a FMIC is that the install process is much longer. Other downsides of FMIC’s can be the much longer piping needed to route compressed air to them. This piping can increase turbo lag and usually has many couplers that can have the potential to leak or cause other issues.

 

So what does CorkSport say? As a general rule we would say if you don’t plan to add more than 50-100 horsepower, a top mount intercooler will work just fine and be much easier on your plans and wallet. If you eventually want to go wild with your car and build it up much higher than stock, you will probably want to look hard at a front mount intercooler. Our advice would be to try to plan in advance what you want out of the car so that you only have to buy parts once.

Happy spooling!

CorkSport Top Mount Intercooler Development Process

The idea for the CorkSport Top Mount Intercooler (TMIC) was originally developed from a thread started by azmavhockey3 on the Mazdas247 forum. This idea exchange by Mazda owners on the forum lead to an in depth development process that included several design iterations, prototype testing, sample testing and finally production testing. The end result was the recently released CorkSport TMIC that provides solid power gains at a great value.

The following graphic demonstrates the development and testing process for the CorkSport TMIC.

(Click Here to download a pdf of the TMIC Development and Testing Infographic)

Read More About the CorkSport TMIC

Gwynne-