Radiators

From the factory, Mazda MX-5 OEM radiators had glossy black plastic headers and clean, unclogged pipes. Over time, and thousands of heat cycles, this plastic turns a stodgy brown/green colour, indicating the plastic header has become brittle. This is a problem as the cooling system’s pressure builds as the temperature does, so if you’re throwing it around a track or even going for a spirited B-road drive, the pressure may build to the point where the plastic cannot expand and either cracks or, worst-case scenario, the header explodes. 

When you add boost, either by turbocharging or supercharging your Mazda MX-5, an upgraded radiator is always recommended. Even on the road, the OEM radiator won’t be able to cope with the heat output of a boosted engine and you’ll begin to experience overheating, potentially damaging your engine. An aftermarket alloy radiator bolts directly into the place of the OEM rad, has a higher coolant capacity, better cooling efficiency and we think adds a better look to the engine bay. 

Aftermarket alloy and aluminium radiators for the Mazda MX-5 often come with ‘high pressure’ caps, these will usually be around 1.3 bar and will allow the whole cooling system to be put under more pressure before the cap opens and starts to vent pressure into the expansion tank. This added pressure allows the cooling system to both store more heat and get up to a higher temperature before boiling, which in turns allows the radiator to dissipate heater much faster.