Rear Cylinder Head Coolant Reroute Kit

The R Theory Motorsports Coolant Reroute Kit addresses a factory cooling imbalance in Mazda MX-5 Miata NA and NB models by redirecting coolant flow to the rear of the cylinder head. This precision-engineered kit is ideal for both street and track applications, aiming to improve performance and reliability. Constructed from premium 6061 aluminum, the kit features a durable blue anodize finish with laser-etched R Theory Motorsports branding, offering a visually appealing addition to the engine bay. Its true one-piece housing design eliminates unnecessary junctions and sharp turns, promoting a straight and efficient coolant flow path. This streamlined design reduces turbulence and minimizes potential leak points. The kit's compact and low-profile design means it is not the highest point in the cooling system, negating the need for a rear bleeder screw. This simplifies the bleeding process, which can be done directly from the radiator. It includes a block-off plate for the front water neck, all necessary hose clamps and fasteners, and offers a choice between OE style rubber or multilayer silicone radiator hose options. A custom stainless steel S-bend coupler is included with the silicone hose kit to prevent kinks in tight engine bays. An optimized 195°F thermostat is included for reliable power generation without compromising cooling capacity. The integrated 1/8” NPT port allows for easy installation of an aftermarket water temperature sensor. However, this kit is not EGR compatible by design due to its compact housing; EGR block-off plates are available separately.