Best Top-Mount Intercoolers for the 2015–2021 WRX: 5 Top Picks Compared
The best top-mount intercooler for a 2015–2021 WRX is the one that matches your power level: the Mishimoto Street core ($665.95) for a tuned daily, the Process West Khanacooler ($735) and Perrin ($799) for bigger cores in the middle, and the COBB ($985, Garrett core) or GrimmSpeed kit ($1,174–$1,284) when the build is serious. All five below are direct-fit for the VA WRX's FA20 — and one fitment warning up front: the WRX STI uses a different top-mount, so STI owners should skip to the guard at the end instead of ordering a WRX core.
The stock VA top-mount was sized for stock boost. Turn the car up and charge temperatures climb, the ECU pulls back, and the third pull feels nothing like the first. A larger bar-and-plate core with real end tanks is the fix that keeps the tune you paid for.
1. Mishimoto [15-21 WRX] Topmount Street Intercooler, Silver — $665.95
The Mishimoto Street Top-Mount Intercooler ($665.95) is the value entry. Per its listing, it is a direct fit for the 2015–2021 WRX, replacing the stock unit with a larger bar-and-plate core and cast aluminum end tanks TIG-welded to it, built to lower intake charge temperatures. It also comes in black and gold finishes at the same price, and Mishimoto sells a matching shroud ($113.95) that seals the core to the factory hood scoop. Street is the right word: this is the core for a tuned daily, not a max-effort build.
2. Process West [15-21 WRX] Khanacooler Top Mount Intercooler — $735
The Process West Khanacooler ($735) is the Australian specialist's answer. Per its listing, the Khanacooler is designed to keep intake air charge temperatures low once you have passed the power limits of the factory top-mount — the point where, as the listing puts it, the stock core starts hindering the rest of your modifications. A black version sells at the same $735. Owners stepping further up the same brand's range can look at the Verticooler ($1,103.44), Process West's vertically-oriented design.
3. Perrin [15-21 WRX] Top Mount Intercooler, Black — $799
The Perrin Top Mount Intercooler ($799) brings the tape measure. Per its listing, the core measures 10.24 in. wide × 13.62 in. deep × 3.75 in. thick — just over 523 cubic inches, 66% larger than stock — with 3/8-inch bar-and-plate construction, and Perrin claims a consistent 10+ wheel horsepower gain from the cooler, denser charge air. The same core is also listed for the Forester XT, and a silver finish is available at the same price. If you comparison-shop by core volume per dollar, this is the one to beat.
4. COBB [15-21 WRX] Top Mount Intercooler, Black — $985
The COBB Top Mount Intercooler ($985) is built around a Garrett core. Per its listing, the 15.75 × 9.65 × 3.94-inch core with cast aluminum end tanks delivers a 31% airflow increase over the stock intercooler, with reinforced couplers and COBB's Thrust Tunnel directing air from the factory hood duct across the core. A silver version sells at the same price, and a kit version bundling COBB's charge pipe is $1,205. For Accessport cars, this is the core the ecosystem was designed around.
5. GrimmSpeed [15-21 WRX] Top Mount Intercooler Kit — $1,174–$1,284
The GrimmSpeed Top Mount Intercooler Kit ($1,174–$1,284 depending on configuration) is the craftsmanship pick. Per its listing, it replaces the undersized plastic-ended stock intercooler with cast aluminum end tanks, a large bar-and-plate core and TIG-welded construction, aimed squarely at cars running increased boost over the factory FA20 setup the stock core was suited to. It is the most expensive core here, and the one aimed at owners who plan to keep turning the car up.
For STI owners: protect the core you have
None of the five cores above fits the VA WRX STI — its EJ top-mount is a different unit. What STI owners can bolt on today is protection: our JDMuscle Top Mount Intercooler Grille Guard ($139–$149) fits 2008–2021 STI top-mounts, comes in multiple color finishes, and installs in minutes with a bolt-on fit, per its listing — cheap insurance against bent fins and road debris through the scoop.
Quick comparison
| Intercooler | Price | Standout spec (per listing) | Best for |
|---|---|---|---|
| Mishimoto Street (Silver) | $665.95 | Bar-and-plate, cast end tanks, direct fit | Tuned daily on a budget |
| Process West Khanacooler | $735 | Built for beyond-stock power levels | Mid builds, Process West fans |
| Perrin (Black) | $799 | 523 cu in core, 66% larger than stock | Core volume per dollar |
| COBB (Black) | $985 | Garrett core, +31% airflow, Thrust Tunnel | Accessport builds |
| GrimmSpeed Kit | $1,174–$1,284 | Cast end tanks, TIG-welded, large core | Serious boost, long-term builds |
How to choose — and what to do next
Match the core to the tune, not the other way round. A stock-tune car gains little from the biggest core here; a tuned car on the stock core is leaving its calibration on the table every warm day. Pair the intercooler with the exhaust side of the same build in our VA WRX and WRX STI cat-back guide, finish the cockpit with our shift knob guide, and if the car is a 2015–2017, the front lip guide is the exterior step that goes with it.