This is the ultimate insurance policy for any street or track-driven EJ20/EJ25. Subaru’s factory cooling design notoriously starves cylinder 4, leading to hot spots, detonation, ring land failure, and blown head gaskets. Our Cylinder 4 Cooling Mod mitigates this by redirecting coolant flow exactly where it’s needed most—dropping #4 exhaust temps by up to 30–40 °C under load. Fully reversible, zero machining, no permanent modifications. Bolt-on in under 2 hours, then enjoy peace of mind for the rest of the engine’s life. Proven on 600+ whp street cars and extremely useful on your stock daily driver as well.
This is the ultimate insurance policy for any street or track-driven EJ20/EJ25. Subaru’s factory cooling design notoriously starves cylinder 4, leading to hot spots, detonation, ring land failure, and blown head gaskets. Our Cylinder 4 Cooling Mod mitigates this by redirecting coolant flow exactly where it’s needed most—dropping #4 exhaust temps by up to 30–40 °C under load. Fully reversible, zero machining, no permanent modifications. Bolt-on in under 2 hours, then enjoy peace of mind for the rest of the engine’s life. Proven on 600+ whp street cars and extremely useful on your stock daily driver as well.
