A key concern with any Subaru EJ engine, which has been tuned for performance or race use, is that of a reliable oil supply. A Dry Sump System can offer levels of safety and reliability which cannot be achieved when utilizing the factory wet sump configuration.
The RCM system completely scavenges the crankcase, which dramatically reduces the excess / residual oil which can cause blow by and consequent power loss associated with this.
In addition to the crankcase scavenging, the RCM 5 Stage kit take a step further, with an additional 2 stages (AN -6 fittings are in place for these stages), this allows both heads to be scavenged one to each stage, or both heads can be scavenged by a single stage by teeing them into 1 inlet, and the 5th used with a low mount turbo.
This dry sump system can deliver a far more consistent oil pressure to the engine, eliminating the oil starvation issues which are associated with the flat 4 boxer type engine configuration. In addition to this the increased vacuum in the crankcase and pan improves the ring to bore sealing properties
WARNING: Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to https://www.P65Warnings.ca.gov/passenger-vehicle.