QMAX Coolant Reroute Kit

The Supermiata QMAX Coolant Reroute is a vital modification for 1990-2005 MX5 Miata models experiencing common overheating issues. However, when adapted for the Miata, the engine was rotated 90 degrees, resulting in an inefficient flow path where coolant enters and exits the head on the same end. This poor flow is a primary cause of overheating, which can lead to reduced power and fuel economy as the stock ECU retards ignition timing. This modification alone significantly reduces coolant temperatures. The housing is internally multi-axis machined and radiused to maximize coolant velocity, a critical factor in improving cooling efficiency. The kit is fully turbo compatible, with thousands in use by competition-proven Miatas, including Supermiata's own championship-winning, high-boost race cars. Key features of the QMAX Reroute include its simple, sealed adapter housing that eliminates leak-prone gaskets and threaded fittings, ensuring zero leaks. It retains the OEM coolant temperature sensor location, so no wiring harness modification is needed. Two spare 1/8 NPT ports are provided for aftermarket sensors, one on the water neck and one on the rear housing. All critical hardware is made from stainless steel for enhanced service life. A convenient bleed port is included for easier system bleeding, and the integrated thermostat housing simplifies fitment and improves reliability. The kit comes with a 195° stainless steel high-flow thermostat, optimized for stock ECUs. An optional 180° thermostat is available for competition builds with programmable ECUs, though using it with a stock ECU can lead to overcooling. An optional cylinder head block-off plate is available if you plan to remove the OEM water neck. Installation typically takes a few hours with common hand tools. Specialty tools recommended include internal snap ring pliers, metric Allen keys, a plastic razor scraper for gasket removal, and a Lisle 24680 funnel. The complete kit includes the reroute housing, thermostat cover, optional head block off plate, coolant neck block off plate, all necessary bolts and hardware, hose clamps, a silicone hose, thermostat, and sealant.