fast

Putting together our final prototype was a bit easier for this project compared to other front-mount intercooler (FMIC) kits our team has developed. As mentioned in previous segments, we used the crash beam and intercooler from our 2015 WRX kit. Now we've worked up some functional prototype piping for a final test fit.

First, let's take a quick look at each portion of the kit.

Intercooler and Crash Beam

The intercooler core is the key component in any intercooler kit. This core has provided significant air temperature drops during our testing on the WRX, and we expect the same results with the STi.

Mishimoto STi intercooler and crash beam

Mishimoto STi intercooler and crash beam

This core was engineered to provide an ideal balance between heat transfer and airflow.

Silicone Components

Mishimoto 2015 STi front-mount intercooler silicone hoses

Kit Accessories

A few brackets and some hardware help piece this kit together for a solid, durable installation. We are also including a BPV (bypass

With our cold-side piping complete, it was time to focus on the hot side. This portion of the piping system would require a bit more attention, mainly because we were unable to scavenge any existing pipes from our WRX/STI front-mount intercooler kits (as we did with the cold side). Let's get to it!

Piping Fabrication

The hot-side piping will route from the turbocharger compressor outlet, around the driver side of the engine bay, and into the front bumper area to attach to the intercooler.

Here is a look at the turbocharger connection point.

2015 STi front-mount intercooler hot-side pipe turbo connection

A coupler attaches the pipe to the turbocharger.

The end of this pipe must attach to our intercooler, which is mounted within the front bumper area. This requires snaking the piping through the engine bay and locating an ideal spot for the piping to travel outside of the engine compartment.

2015 STi Intercooler pipe connection

We should have no issues routing our pipe between the washer

Our first segment of this STI intercooler project involved the test fitting of our WRX crash beam and intercooler core. We were able to verify fitment of both pieces, which allowed our team to move on to piping fabrication. We are starting this kit with the cold-side pipe, which we've decided to place this on the passenger side of the engine bay to reduce the piping length as much as possible. Following this strategy should help reduce lag seen by the driver.

Pipe Fabrication

The cold-side pipe is a great place to start because we are able to use a portion of one of our existing kits. Because the 2015 model shares the EJ from the 2008+, we will be reusing the pipe that attaches to the throttle body and incorporates the BPV (bypass valve).

2015 STI front-mount intercooler development

This pipe provides optimal clearance through its path within the engine bay. It routes from the throttle body into the portion of the engine bay that previously contained the intake airbox.

2015 STI front-mount

We've given the 2015 WRX quite a bit of love, mostly due to the introduction of the FA20DIT within the new chassis. Our team developed a ton of awesome components: a downpipe, an intake system, a couple different intercooler options, and various other neat parts. With our WRX projects mostly wrapped up, it's time to turn our attention towards the STi. It still has an EJ engine under the hood, but it is mated to a new chassis that many are taking advantage of in various forms of competitive racing.

So far we have developed an intake and a cat-back exhaust for the STI. Our next target is a bolt-on front-mount intercooler (FMIC) kit for the 2015 STI. The EJ25 is a well-respected engine that can make great power from basic bolt-ons and tuning. In addition, the sky is the limit in terms of power output once engine internals are upgraded and a large snail is bolted up. Greater power means more heat, resulting in the need for a more efficient heat exchanger for the charge-air system. Thus, we

Interested in purchasing our 2015 STi intake system? Check out more details on our product page linked below!

Mishimoto Subaru STI Performance Air Intake

As noted earlier in this article series, we would be tackling a race intake system to go along with our bolt-on unit. So what makes the race system different? For this particular system we are using a larger-diameter intake pipe with a larger MAF housing. This means greater intake flow, but it also means it will no longer function with the factory tune. This system is meant specifically for drivers who want aggressive professional tunes so they can take advantage of airflow modifications such as larger turbochargers and high boost pressures.

Because the 15' model shares the EJ from the previous generation, we would be using the same intake pipe and filter as we did with our 2008-2014 kit. This unit is shown below.

So, all we truly needed was to design an airbox that would accommodate this pipe and function with the body of the new 15'

Interested in purchasing our 2015 STi intake system? Check out more details on our product page linked below!

Mishimoto Subaru STI Performance Air Intake

Dyno Testing

Time to see what kind of power gains we are able to achieve with our intake design! First, we strapped this Launch Edition to the dynamometer.

2015 STI on the dynamometer

2015 STI on the dyno

Then we began making pulls. On our first day we tested only the stock intake system. Once complete, we installed the Mishimoto intake system and sent the vehicle out for some road testing. We wanted to allow the ECU to adjust to the new intake before making our pulls. After well over 150 miles of road use, we returned the next day to compile dyno data for the Mishimoto intake.

2015 STI on the dyno

Testing Results

So how did we do? Well, I think the plots below summarize our results quite well.

Mishimoto intake shroud render

Thank you very much for following along with the progress of our intake. This was quite an exciting project!

We

Interested in purchasing our 2015 STi intake system? Check out more details on our product page linked below!

Mishimoto Subaru STI Performance Air Intake

Prototype Fabrication

After experimenting with some boxed designs in Part 1 of this write-up, it was time to turn our attention to a shrouded setup, similar to what we offer for the 2008-2014 models. We're hoping we could utilize the piping from our existing kit, which is well designed and has proven power gains. After placing the shroud into position, we found that it would certainly fit, but would require some modification. The fabrication work began! Check out a few shots taken during the process.

Mishimoto intake shroud modification

Mishimoto intake shroud modification

Mishimoto intake shroud modification

Once all fab work was completed, we had a functional shroud that we could use for testing purposes. We could also use this shroud to develop a 3D model for our production units. Take a look!

Mishimoto modified intake shroud

Mishimoto

Interested in purchasing our 2015 STi intake system? Check out more details on our product page linked below!

Mishimoto Subaru STI Performance Air Intake

Launch Edition Subaru STI in Mishimoto garage

Introduction

Our team is finally working on some cool components for the new 2015 Subaru STI! As you know, the 2015 STI is essentially a hybrid of old and new Impreza components. It features the newer body style paired with the trusty EJ engine, instead of the new DIT motor featured in the WRX. We won't get into which is better or which we prefer, because we have nothing but praise for the updated chassis. Our team has spent a great deal of time with both vehicles, and we are impressed with how the STI drives, handles, brakes, and functions as a comfortable yet sporty sedan.

As you may already know, we developed an intake system for the 2015 WRX recently, and we had a ton of success producing some really nice power gains. We also offer an intake system for the 2008-2014 WRX/STI equipped with

Interested in purchasing our Subaru WRX or STi intercooler kit? Check out more details on our product pages linked below!

Mishimoto Subaru WRX/STi Front-Mount Intercooler, 2001-2007

Mishimoto Subaru WRX Front-Mount Intercooler, 2008-2014

Mishimoto Subaru STi Front-Mount Intercooler, 2008-2014

Time to review our data so we can finally put a close on this project. The product development process for this front-mount intercooler has taken months and has also helped refine several of our processes. Before we move into the testing data, our first portion of this post will cover the physical benefits of our intercooler. By providing a more efficient heat exchanger, we can ensure that higher-powered vehicles are not being hindered by debilitating heat-soak and/or inefficiencies with the use of a top-mount intercooler setup.

Our first comparison point is internal flow area. This graph shows the volume of the actual air passages through the intercooler.

Comparison of internal flow area

Internal

Interested in purchasing our Subaru WRX or STi intercooler kit? Check out more details on our product pages linked below!

Mishimoto Subaru WRX/STi Front-Mount Intercooler, 2001-2007

Mishimoto Subaru WRX Front-Mount Intercooler, 2008-2014

Mishimoto Subaru STi Front-Mount Intercooler, 2008-2014

We are nearing the end of this build. As mentioned in the last post, we wanted to put our core to the test and provide some cooling efficiency data that our customers could use. We decided to modify our 2010 STi to add some heat and power to the CAC system for testing. Information regarding our vehicle is listed below.

2010 Subaru WRX STI

• 6-Speed Manual
• Mishimoto Intake
• Mishimoto Front-Mount Intercooler
• Fuel Line Modification
• 3" Downpipe
• Tune

Check out a few shots of the car on the dyno!

Mishimoto GR STI on the dyno

Mishimoto GR STI on the dyno

As you can see, we have sensors installed on the piping, both the cold- and hot-side of the intercooler. We have pressure and temperature sensors hooked up