KOYORAD Radiator for Subaru WRX & STI

• KOYORAD main collection — the full KOYORAD range at Chicane Australia
• KOYORAD Radiator for Nissan Skyline R32, R33, R34 & GT-R
• KOYORAD Radiator for Toyota 86, Subaru BRZ & GR86
• All brands stocked at Chicane Australia

On this page: Subaru Impreza WRX and WRX STI applications, including shared fitment with Legacy GT, Forester XT and Outback XT on the relevant chassis.

Transmission check before you order

KOYORAD radiators for the 2002–2021 WRX/STI are manual transmission only. The Hyper V-Core does not include the internal transmission cooler fitted to automatic WRX/STI models. Automatic cars can only use the same radiator with the addition of an external auxiliary transmission cooler — contact us before ordering if your car is an automatic so the supporting parts can be specified correctly.

Chassis and engine fitment

• GC8/GF8 Impreza WRX / WRX STI: Hyper V-Series aluminium racing radiator.
• GD/GG chassis (2002–2007) — KOYORAD VH091672: Impreza WRX 2003–2007 and WRX STI 2004–2007 (EJ205, EJ207, EJ255, EJ257).
• GRB/GVB/GH/VA chassis — KOYORAD VH091662: 2008–2014 WRX (EJ255), 2008–2021 STI (EJ257), 2015–2021 WRX (FA20F), plus 2005–2012 Legacy GT (EJ255), 2005–2009 Outback XT, 2009–2013 Forester XT.
• VB chassis WRX: KOYORAD aluminium performance radiator for the current WRX.
• 2002 model year WRX: requires the 2002-specific radiator (VH090866). Check whether your factory radiator has a radiator cap — early WRX without a radiator cap need that specific unit.

Specifications — GRB/GVB/VA (VH091662)

• Core: 36mm Hyper V-Core, full aluminium construction
• Dimensions: core depth 1.41", core height 13.38", core width 26.65"
• Weight: 12.1 lbs (approx. 5.5kg)
• Construction: hand TIG-welded end tanks, Nocolok-brazed core, billet machined filler neck
• Optional accessory port: M14-1.25 thread for an aftermarket sensor
• Manual transmission only (no internal transmission cooler)

Specifications — GD/GG (VH091672)

• Core: 36mm Hyper V-Core, full aluminium construction
• Dimensions: core depth 1.40", core height 13.40", core width 25.50"
• Weight: 11.8 lbs (approx. 5.4kg)
• Construction: hand TIG-welded end tanks, Nocolok-brazed core, billet filler neck and 1/8 PT accessory port (plug included)
• Manual transmission only

Why these Subarus benefit from a radiator upgrade

The symmetrical AWD layout places the boxer engine forward over the front axle, and airflow to the radiator is shared with the intercooler and front ducting, so the factory radiator sits in a tight package. Factory units use an aluminium core with plastic end tanks, and the tank-to-core seam is the common failure point as the plastic becomes brittle with repeated heat cycling. Tuned cars also generate more heat than the standard radiator was sized to dissipate, which typically shows up as higher coolant temperatures during track use or hot-weather driving rather than around town. The Hyper V-Core answers all three with full aluminium construction and a dense 36mm core in the same footprint as the factory radiator.

Installation by a qualified professional workshop is recommended. Cooling system work involves draining and refilling coolant, correct bleeding and disposal of used coolant.

The KOYORAD fits the factory radiator position using the OEM mounting points, OEM fan shroud bolt pattern and OEM hose locations. No cutting, bracket modification or relocation of supporting components is required.

• Upper radiator hose: because the thicker core changes the effective face of the radiator, the upper coolant hose may need to be shortened slightly for correct clearance.
• Fan clearance: the Hyper V-Core's fan mounting points sit slightly further forward than OEM. On cars with large-diameter aftermarket cold-side charge piping routed past the passenger-side fan, removing the intercooler and charge pipe during fan installation and refitting the boost plumbing afterwards avoids fouling.
• Radiator cap: not included, as cap pressure ratings vary by build. The OEM cap fits the KOYORAD filler neck; the KOYORAD SK-C13 1.3 Bar cap is available as a higher-pressure option.
• Also have on hand: fresh coolant to the correct specification, a drain container, and new hose clamps if the originals are tired.

Will a KOYORAD radiator fit an automatic WRX or STI?

Not on its own. KOYORAD radiators for the 2002–2021 WRX/STI are manual transmission only and have no internal transmission cooler. An automatic car needs an external auxiliary transmission cooler added, so contact us before ordering.

Which KOYORAD suits my chassis code?

GD/GG cars use VH091672, GRB/GVB/VA cars use VH091662, 2002 model year WRX use VH090866, and there are separate radiators listed for GC8/GF8 and VB applications.

Is a radiator cap included?

No. Most owners reuse the OEM cap, which fits the KOYORAD filler neck. The KOYORAD SK-C13 1.3 Bar cap is available if a higher-pressure cap is preferred.

Does it need modification to fit?

It uses the factory mounting points, fan shroud bolt pattern and hose locations. The upper coolant hose may need slight trimming, and fan clearance should be checked on cars with large aftermarket charge piping.