RCM's dry sump system is engineered as the ultimate solution for resolving Subaru oil supply issues. The dry sump oil pump mounts directly to the supplied oil pan and is driven from the timing belt idler via a cogged belt. The pressure stage feeds pressurized oil to the engine via a CNC machined cover that bolts in place of the original oil pump. A non-oil cooler water pump is supplied in order to eliminate the factory oil cooler water pipe that would otherwise interfere with the oil pump drive. Fittings and hardware are supplied to complete the installation. The dry sump system is now made by Auto Verdi and incorporates a 4-stage system (3 scavenge stages and 1 pressure stage). A pressure adjustment and optional alternative springs allows for a wide ranging pressure setting.
The dry sump system reduces residual oil and crankshaft windage and improves ring sealing by generating a slight vacuum in the crankcase. Oil starvation issues with the factory oil pan and oil drainback system are effectively eliminated by allowing the use of a high capacity external oil reservoir. Minimal oil pan/pump height allows for increased ground clearance.
A dry sump oil tank and interconnecting hoses must be fabricated or supplied by the installer or end user as these parts are not included in the kit. Professional installation is highly recommended.
Special Order
What is the advantage of a dry sump system? Probably the most important advantage is that it allows for optimal control of the oil around the pump pickup against severe cornering, acceleration, and braking forces avoiding oil starvation. It also allows increased system capacity improving oil cooling and de-aeration. Crankshaft windage is reduced by keeping liquid oil away from the spinning crankshaft and by reducing the pressure in the crankcase. Another advantage is with regards to the crankcase ventilation system by minimizing the oil mists and vapors that are allowed to be drawn into the intake system.
Does RCM offer a kit to complete the installation? At the present time they only offer an installation kit for right hand drive models. The location of the tank mounting is not compatible with a left hand drive installation. We can supply this kit by special order (please email).
What is a scavenge stage? The pump consists of multiple segments, or stages, within the main housing to pump oil. The scavenge stages are used to pull oil out of the engine while the pressure stage pumps oil back into the engine. The scavenge stages are connected to the ports in the oil pan to pull oil out of the pan. There are additional options for porting one of the scavenge stages either to the turbo oil drain (for example a low mounted turbo) or via a T-fitting to both cylinder heads to aid in situations where oil cannot drain back from the heads easily (for example high G cornering on the track).
Does the pump pulley clear all exhaust manifolds? No, we can't guarantee the pump drive will clear all exhaust manifolds. It may be necessary to change the manifold or modify it for clearance. Additionally be aware that the center timing cover needs to be modified so that the supplied timing belt idler w/ pump drive can extend through the cover. A template is supplied to aid in knowing the exact size and location of the hole that must be cut.
