2008-2014 (GR)

Interested in picking up our 2008-2014 WRX/STi overflow tank? Check out our discounted pre-sale linked below.

2008-2014 Subaru WRX aluminum overflow tank pre-sale!

We last left you with some details of our initial design and a hint of an upcoming pre-sale for this overflow tank. Unfortunately, since that initial test fit we hit a few snags in the design process. Our goal with this product is to provide compatible fitment with all our other 2008+ WRX and STi components. This required numerous stages of test fitting, one of which revealed an issue. With our larger 3-row X-Line aluminum radiator installed, our sight tube on this expansion tank design ended up too close to the belt drive system on our Subaru.

We decided a revision was necessary. Although the two components were not physically touching, the clearances were just too tight for our comfort. Luckily, our team had an alternate means of measuring fluid within the tank. This comes in the form of a dipstick!

Check out a few 3D models

Interested in picking up our 2008-2014 WRX/STi overflow tank? Check out our discounted pre-sale linked below.

2008-2014 Subaru WRX aluminum overflow tank pre-sale!

If you haven't noticed, the folks here at Mishimoto are not fans of plastic use for cooling system components. A large number of our products provide a more durable material, aluminum, to replace the failure-prone plastic parts, and now we are focusing on another line of products, our aluminum coolant expansion tanks. We offer two different options for the WRX/STI and one for the new Mustang EcoBoost. This article is focused around our newest addition, an aluminum overflow tank for the 2008+ WRX and STI.

Product Design

We won't be making any significant changes to the design of this tank compared to the stock unit, except for the construction material. Enlarging the tank's capacity will have no impact on fluid temperatures or cooling efficiency, so this will not be necessary.

We snagged a stock overflow tank and started gathering

Interested in picking up this awesome aluminum expansion tank? Check out more details on our product page linked below!

Mishimoto Subaru WRX Aluminum Coolant Expansion Tank

Last year we released an aluminum expansion tank for the 2004-2014 STI and 2002-2007 WRX. We received a ton of awesome feedback from customers and enthusiasts regarding this component, as well as recommendations to produce such a tank for 2008-2014 WRX owners.

While we normally highlight our development process in multiple installments, for this Expansion Tank we wanted to give you everything in one quick shot.

Stock Expansion Tank

Although we don't see quite as many failures with the 2008-2014 expansion tank, we can assume it will incur some wear over time. This tank sits relatively close to a very hot turbocharger/exhaust and handles coolant with temperatures over 200°F. With this kind of exposure, we frequently see plastic components degrade and crack/split, resulting in leaks.

Here is a look at the stock expansion

Interested in purchasing our WRX or STi catch can system? Check out more details on our product pages linked below!

Subaru WRX Baffled Oil Catch Can System

Subaru STi Baffled Oil Catch Can System

After completing the fabrication of our brackets for this kit and assembling the STI-specific lines, it was time to tackle the WRX. As you may be aware, the stock CCV lines are slightly different on the WRX, which necessitates a separate set of WRX-specific catch can lines.

The Test Subject

After reaching out to local contacts, we found a willing vehicle donor just one state away. We have borrowed this particular vehicle on several occasions for a variety of test fittings. A big "thank you" to the owner for lending his vehicle and his time for the sake of awesome new product development!

2011 WRX test-fit vehicle

This vehicle is kept super clean; check out the engine bay!

2011 WRX test-fit vehicle engine bay

This owner also has our cold-air intake setup installed!

Mishimoto intake installed

WRX

Interested in purchasing our WRX or STi catch can system? Check out more details on our product pages linked below!

Subaru WRX Baffled Oil Catch Can System

Subaru STi Baffled Oil Catch Can System

Mishimoto 2010 STI

After developing a highly successful, direct-fit catch can setup for the 2015 WRX we turned our attention to the previous generation. Our next target would be the 2008-2014 WRX and STI. At this point, Mishimoto still owned a 2010 STI, and this project would be our last for our shop vehicle.

Catch Can Selection

As with our 2015 WRX project, we would be using a dual catch can system to address both the PCV line and the crankcase breather line. One of the main differences would be the inclusion of a three-port breather catch can to replace the two-port unit used on the FA20 engine. The EJ engine features a breather line for each valve cover, which necessitates a dual-in, single-out catch can for that system. The PCV line would still use a standard dual-port catch can for the EJ.

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

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

As promised, we have a couple cool images showing these kits fully installed on our test vehicles. Check them out below!

First, our full kit installed on our shop 2003 WRX Bugeye wagon!

Bugeye wagon with Mishimoto kit fully installed

This intercooler fills out the bumper completely and looks fantastic. Next up, a look at this kit fully installed on the Hawkeye.

Hawkeye with Mishimoto kit fully installed

And a couple shots of our finalized GR STi kit!

GR STi with Mishimoto kit fully installed

GR STi with Mishimoto kit fully installed

Now that we had all of our kits developed, the project is complete, right? Wrong! We haven't tested this intercooler out yet! Now, we have conducted a ton of CFD and core