Mishimoto MMTMIC-STI-08BKBK Top-Mount Intercooler for 08-21 Subaru WRX S

Vehicle Fitment

• 2008-2021 Subaru WRX STI (EJ257/EJ255, AWD)
• Fitment confirmed through 2025. 2026 unconfirmed at time of listing.

Features

• Direct-fit top-mount intercooler kit designed for WRX STI models
• Dense bar-and-plate core for optimal heat transfer
• 3.75" thick core with 584 in³ volume for improved cooling capacity
• Durable cast aluminum end tanks TIG-welded for structural strength
• Includes black silicone hoses and clamps for a clean OEM-plus look
• Improves intake air temperature stability during spirited driving
• 10 °F temperature reduction vs stock intercooler under load
• Proven +5 whp and +7 wtq performance gains on stock engines

Specifications

• Core type: Bar-and-plate aluminum
• Core thickness: 3.75"
• Core volume: 584 in³
• Core length: ~21"
• Core height: ~7.25"
• Overall width: ~4.25"
• Overall length: ~24.5"
• Finish: Powder-coated black with black silicone hoses
• Compatible with stock A/C line and Y-pipe - no modifications needed

Included Components

• 1x Top-mount intercooler core
• 1x Intercooler-to-throttle body transition coupler
• 1x PCV silicone hose
• 1x Bypass valve (BPV) gasket
• 2x Y-pipe to intercooler gaskets
• 1x Black nylon hose fitting (3/4" I.D.)
• 1x Black nylon tee fitting (3/4" I.D.)

Product Description

The Mishimoto MMTMIC-STI-08BKBK Top-Mount Intercooler Kit is a performance-focused upgrade for turbocharged Subaru WRX STI models from 2008 through 2021, powered by the EJ257 or EJ255 engine codes. This direct-fit intercooler uses a dense bar-and-plate aluminum core with a substantial 3.75" thickness and 584 in³ volume to improve intake charge cooling efficiency over the stock intercooler. During testing, it delivered approximately a 10 °F reduction in intake air temperature and measurable gains in power and torque on factory engines, making it ideal for street and track use alike.

Constructed with robust TIG-welded cast aluminum end tanks and finished with sleek black powdercoat, the MMTMIC-STI-08BKBK installs directly into the factory mounting points without requiring modification to the vehicle's A/C lines or intercooler Y-pipe. Included high-quality black silicone hoses and OEM-style fittings ensure a secure fit and an integrated appearance. Backed by Mishimoto's Lifetime Warranty, this intercooler provides enhanced thermal performance and lasting durability for drivers seeking improved boost response and cooling under hard driving conditions.