2008-2014 Subaru STI Performance Top-Mount Intercooler, Part 3: Prototype and Stock Comparison

2008-2014 Subaru STI Performance Top-Mount Intercooler, Part 3: Prototype and Stock Comparison

Interested in purchasing our STI intercooler? Check out our product page for more information!

Mishmoto Subaru WRX STi Performance Top-Mount Intercooler Kit

So just how much better is the Mishimoto top-mount intercooler (TMIC) compared to the stock unit? Well " only our testing will confirm this. Physically we can already see several improvements. Let's compare the core size in a simple chart.

Comparison of core thickness in stock intercooler (left) and Mishimoto TMIC prototype
Comparison of core thickness in stock intercooler (left) and Mishimoto TMIC prototype


A look at the bottom of both intercoolers reveals quite a few differences.

Stock vs Mishimoto TMIC prototype
Stock vs Mishimoto TMIC prototype

Stock vs Mishimoto TMIC prototype
Stock vs Mishimoto TMIC prototype

In addition to the increased size, you will also notice that our inlets are different than those on the stock cooler. This feature sets our cooler apart from any other product on the market. We designed these ports with both flow and air dispersion in mind. Check out the close-up below.

Stock (top) vs Mishimoto TMIC prototype, intercooler inlets
Stock (top) vs Mishimoto TMIC prototype, intercooler inlets

The most obvious change is the diverters we have placed in the center of each port. Through CFD testing we found that by adding these diverters we are better able to disperse air throughout the length of the core. Improved dispersion means that more of the core is being used to transfer heat; therefore, we are optimizing the size of our core for actual results.

Check out the CFD comparison of the stock cooler and the Mishimoto prototype below. The dot is a graphical representation of airflow. The dot color denotes the velocity of air at that point in the cooler: red (highest velocity), yellow, green, and blue (slowest). This analysis shows that the factory Y-pipe is rather efficient for airflow. It also shows the effectiveness of our diverter and end-tank design at pushing airflow to the entire core.

CFD analysis of stock cooler (top) and Mishimoto TMIC prototype cooler
CFD analysis of stock cooler (top) and Mishimoto TMIC prototype cooler

Additionally, we have increased the size of these ports to improve flow. Yes, these will still mate up to the factory Y-pipe; however, a larger gasket is needed to take advantage of this flow increase. We are including a gasket for both inlets! Check out the comparison of the stock sizing to the Mishimoto unit.

Stock intercooler inlet sizing
Stock intercooler inlet sizing

Mishimoto prototype intercooler inlet sizing
Mishimoto prototype intercooler inlet sizing

Now, a few millimeters may not seem like much, but if you know anything about porting you will understand that every little bit helps. Our size gains are summarized in the chart below.

Mishimoto intercooler inlet
Mishimoto intercooler inlet


Last, take a quick look at the end tank comparison of the factory unit against our prototype. We designed quite a beefy unit!

Comparison of Mishimoto end tank (left) vs. stock end tank
Comparison of Mishimoto end tank (left) vs. stock end tank

Comparison of stock end tank (left) vs. Mishimoto end tank
Comparison of stock end tank (left) vs. Mishimoto end tank

And finally we have a few really neat renderings of the end tanks for our prototype unit. Extreme care and precision went into the design of these components and it really shows here.

Rendering of Mishimoto prototype cold-side end tank
Rendering of Mishimoto prototype cold-side end tank

Rendering of Mishimoto prototype cold-side end tank
Rendering of Mishimoto prototype cold-side end tank

Rendering of Mishimoto prototype hot-side end tank
Rendering of Mishimoto prototype hot-side end tank

Rendering of Mishimoto prototype hot-side end tank
Rendering of Mishimoto prototype hot-side end tank

Rendering of Mishimoto prototype hot-side end tank
Rendering of Mishimoto prototype hot-side end tank

That about wraps up our initial comparison of the stock unit to our prototype. Check back next week when we will be preparing the coolers for testing and collecting our data on the dyno!

Thanks!

Interested in purchasing our STI intercooler? Check out our product page for more information!

Mishmoto Subaru WRX STi Performance Top-Mount Intercooler Kit