QMAX Coolant Reroute Kit

The QMAX Coolant Reroute is a performance cooling system modification specifically designed for 1990-2005 Mazda MX-5 Miata models. The B series engine's original design, intended for a front-wheel-drive configuration, featured an efficient coolant flow path. However, when mounted transversely in the Miata, the coolant exit was moved to the same end as the inlet, leading to poor flow and common overheating issues. This QMAX reroute kit corrects this by installing a low-profile adapter at the back of the head, restoring the effective front-to-back coolant flow and significantly reducing engine temperatures. Constructed from robust 7075 T-6 aluminum, the reroute housing and thermostat cover are built for durability and performance. The internal surfaces are multi-axis machined and radiused to maximize coolant velocity, a critical factor in improving cooling efficiency. This system is fully compatible with turbocharged setups, having been utilized in some of the fastest track Miatas. It retains the factory coolant temperature sensor location, meaning no modifications to the wiring harness are necessary. Additionally, two spare 1/8 NPT ports are provided on the water neck and rear housing for the installation of aftermarket sensors. All critical hardware components are stainless steel for enhanced service life. Installation of the QMAX Coolant Reroute is estimated to take a few hours for an average mechanic using common hand tools. The kit is comprehensive, including the reroute housing, thermostat cover, and all necessary hardware, such as a high-flow 195°F thermostat (with options for a 180°F thermostat for competition builds), various clamps, hose barb, drain plug, and sealant. Optional components, like a cylinder head block-off plate, are also available. Recommended specialty tools include internal snap ring pliers, metric allen keys, a plastic razor scraper, and a funnel. This coolant reroute modification not only combats overheating but also prevents the stock ECU from reducing ignition timing due to high temperatures, thus preserving power and fuel economy. It is competition proven and thousands are in use worldwide for various forms of motorsport, including Autocross, Time Attack, Road Racing, and Enduro, as well as for daily driving. Note that for models equipped with COPS ignition, a convenient bleed port is included for easier system bleeding. Some users may need to slightly modify the stock EGR pipe for clearance, as variations exist in OEM EGR pipes.