The RCM O Ringed Thermal spacer kit contains everything required to install our Phenolic Spacers to your Subaru.

The kit is designed to aid in the reduction of the air inlet temperatures in the inlet manifold, by isolating the manifold from the heat travelling through from the engine's cylinder heads. Sealing between the spacers, manifold and cylinder heads is by the clever integral double "O ring" design meaning conventional manifold gaskets are no longer required.

By reducing the temperature of the inlet manifold, the temperature of the inlet charge is reduced. The density of cooler is greater than that of warm air, and a denser intake air charge contains more oxygen which results in the potential for increased power and torque.

Not only can the thermal spacers help reduce heat transfer, but they can also help give you additional space under the inlet manifold for larger turbo inlet hoses and engine plumbing.