Perrin - Subaru 08-14 WRX/STI - Air Oil Separator (Red) subaru-wrx-2025 the denser the air becomes

the denser the air becomes and that’s what helps eliminate pre-detonation

The design incorporates cooling fins to aid in dissipating heat from the oil as air passes over them

Over time the factory hoses become brittle and crack

Installation is a breeze with the included hardware

As with all of our 2015 WRX parts

Perrin - Subaru 08-14 WRX/STI - Air Oil Separator (Red) subaru-wrx-2025 the denser the air becomesOVERVIEW The PERRIN Air Oil Separator traps oil from the crankcase vents before it enters the intake, reduces carbon build up, increases intercooler efficiency, which reduces the chance of performance robbing detonation. NO TUNING REQUIRED Increase horsepower and torque without ECU recalibration or tune! This part is designed and tested to work safely on your vehicle without any tuning required! However, more power can be gained with proper ECU