Mishimoto® (15-21) Subaru WRX Race Top Mount Intercooler Kit

Compatible: (2.0L)

2015 - 2021 Subaru WRX

This kit is rated for 300–450 whp with maximum limits of approximately 500 whp, or 35 psi of turbo boost. Exceeding that horsepower or pressure limit may require a larger front-mount intercooler.Tuning is not necessary after installing our top-mount intercooler and charge-pipe, but you will see optimal performance if tuning is performed after the intercooler is installed.The top-mount intercooler will not fit with the stock engine cover due to its larger size.Charge Pipe Construction: Aluminum casting with T6063 aluminum tubing

Are you looking for a way to reduce high intake temperatures on your stock or modified 2015+ Subaru WRX? The solution is the Mishimoto direct-fit 2015+ Subaru WRX Race top-mount intercooler kit engineered specifically for your highly modified 2015+ Subaru WRX. The stock 2015+ Subaru WRX intercooler is prone to heat soak during repeated wide open throttle pulls and during track use.

Mishimoto engineers spent months designing the 2015+ Subaru WRX parts and testing this top-mount intercooler to ensure optimum performance on your highly modified WRX. This intercooler utilizes durable cast aluminum end tanks TIG-welded to a highly efficient, dense bar-and-plate core. The Mishimoto 2015+ Subaru WRX intercooler has a 4” thick core and a total volume of 625 cubic inches, making it one of the largest top-mount intercoolers you can buy.

Thanks to this volume and a very dense offset fin pitch, we are able to optimize heat transfer and support your vehicle from stock up to 500 whp. This WRX intercooler endured rigorous testing, showing a 35°F temperature drop as well as a 15 whp and 8 wtq bolt-on power increase for our test vehicle equipped with a Mishimoto 2015+ Subaru WRX downpipe and stage 2 EcuTek tune. Installation is simple, requires no modification to any parts in the engine bay, and can be completed in under 1 hour. Included with this top-mount intercooler is Mishimoto’s innovative 2015+ Subaru WRX charge-pipe, utilizing a one-piece construction without the need for several couplers and clamps. An application-specific air splitter is included with the top-mount intercooler to help divert the maximum amount of air into your Mishimoto 2015+ Subaru WRX top-mount intercooler.

The WRX top-mount intercooler kit also includes a new charge-pipe to intercooler hose, an intercooler to throttle body hose, and a new bypass valve hoses. These 2015+ Subaru WRX parts negate the need to gather supplies for installation, and they ensure years of reliable service. This Subaru WRX intercooler is available in a durable powder-coated finish of Silver and Black, with your choice of either a polished, wrinkle black, or wrinkle red pipe, and, like all our Subaru WRX parts, this top-mount intercooler kit includes the Mishimoto Lifetime Warranty.

• Direct fit for the 2015+ Subaru WRX
• Designed for optimal performance on highly modified vehicles using stage 2+ tuning
• Power gains of up to 15 whp and 8 wtq on performance tune
• 35°F temperature drop compared to stock intercooler on performance tune
• 100% aluminum construction with durable cast end tanks TIG-welded to a highly efficient bar-and-plate core
• Mandrel-bent aluminum Mishimoto charge-pipe included to increase flow characteristics
• Includes larger air duct designed to provide optimal airflow to the Mishimoto intercooler core
• Includes new BPV hoses, hot side coupler, and silicone throttle body hose
• Pre-marked area for NPT sensor
• Available in silver or black intercooler with the option of a polished, black or red hot-side charge pipe
• CARB EO #: D-759
• Mishimoto Lifetime Warranty

PURCHASE INCLUDES

(1) Bar-and-Plate Intercooler
(1) Optional Charge-Pipe
(1) Intercooler Mounting Bracket
(1) Air Diverter with Attached Rubber Gaskets
(1) Charge-Pipe to Intercooler Hose
(1) Intercooler to Throttle Body Hose
(3) Bypass Valve Hoses
(2) 3" T-bolt Clamp
(2) 3.5" T-bolt Clamp
(4) Worm-Gear Clamps
Mounting Hardware
Mishimoto Lifetime Warranty

NOTES

This kit is rated for 300–450 whp with maximum limits of approximately 500 whp, or 35 psi of turbo boost. Exceeding that horsepower or pressure limit may require a larger front-mount intercooler.Tuning is not necessary after installing our top-mount intercooler and charge-pipe, but you will see optimal performance if tuning is performed after the intercooler is installed.The top-mount intercooler will not fit with the stock engine cover due to its larger size.Charge Pipe Construction: Aluminum casting with T6063 aluminum tubing

VEHICLE SPECS

PRODUCT SPECS

Time for the fun part of development, product testing! Since this is an intercooler, we would certainly need to put the WRX on the dyno for some pulls and data collection. It would be interesting to see how the installation of a front-mount system has an impact on turbo spool, intake temperatures, and perhaps even power output.

Testing Preparation

The first step toward data collection is to prepare our sensor bungs and install our pressure and temperature sensors. We installed our bungs within the inlet and outlet intercooler couplers.

Dyno Testing

Once complete we strapped the WRX to the dyno and started making our pulls! Check out the images and video from our tests!

Testing Results

After making several pulls we compiled our results into a series of charts that should help you make an informed decision regarding your intercooler needs. Do you need a front-mount? Is the stock top-mount going to be sufficient for your needs? These great quandaries of the mind are answered below.

First, a look at outlet temperatures of the stock intercooler setup compared with our front-mount system.

At the start of the pull, the front-mount already shows improvements, displaying a 20°F temperature drop compared to the stock intercooler. As the pull progresses, the top-mount outlet temperatures begin to rise at around 4,300 rpm and eventually peak at around 120°F . The front-mount setup starts at around 70°F  and peaks at right around 82°F toward the end of the pull. This reflects a nearly 40°F difference in intake temperatures! Also, keep in mind that our ambient temperature in the shop is right around 65°F, so our front-mount system is keeping temperatures to within 17°F of ambient – pretty impressive! In a nearly identical test with our new 2015 WRX top-mount, we saw peak temperatures around 90°F.

Our next chart shows outlet temperature relative to boost pressure.

This chart shows outlet temperatures during spool. The entire length of this plot data was collected in the short amount of time it takes to increase from 4 psi to peak pressure. As you can see, both plots stay relatively level during this time. Only during sustained high boost does the temperatures begin to rise, and we see a bigger difference between the two intercoolers. That said, we are still seeing about a 20°F drop between the two cooler setups during initial turbo spool.

The next chart is the one folks have been waiting for. Front-mount intercooler setups typically produce greater lag, which is why one might stray from this particular setup on a lower-powered build. To demonstrate this we produced the chart below, which shows PSI/RPM for the stock intercooler system and the Mishimoto front-mount.

We started our pulls at around 3,000 rpm, which showed around 6 psi of pressure for both setups. Through 18 psi we were able to achieve nearly identical pressure per rpm. You will also notice the front-mount peaks at a slightly higher pressure, which is likely due to the lower intake temperatures. Either way, lag with the front-mount was extremely minimal.

Piping Modification

After fitting the bumper once again, we decided clearances were a bit tighter than we wanted on the cold side. Instead of having this pipe potentially rub the back of the bumper, we decided to modify the route a bit to provide improved fitment. Both the upper and lower portions of this pipe were modified.

In addition to the new route, we intend to manufacture a portion of this piping out of wire-reinforced silicone. This portion will be passing between the headlamp and the washer reservoir. By using silicone we can ensure that the component will not be damaged from rubbing and will not vibrate or cause noise concerns within the cabin.

Catch Can Use

We do our best to make each of our components compatible with each other, and we were able to do so with a majority of our products, excluding our direct-fit catch can kit. Unfortunately the cold-side piping interfered with our driver’s side catch can mounting bracket. With a bit more space in the rear of the engine compartment, we were able to relocate this unit with a new bracket and revised lines. Check it out!

Thanks for taking a look at our progress! Now that this kit is complete, we will begin manufacturing units and should have these kits on shelves in the near future. Keep an eye out for a few small additional updates in the following weeks regarding our final product.

Engineering Report: