Supermiata Crossflow Radiator MX5 Miata 90-05

Crossflow Radiator

89-05 Miata MX5 Requires DIY modification to clear Mazdaspeed MX5 OEM intake tubing and changing to 2-piece OEM radiator fans

The proven best crossflow for the 90-05 Miata

• • Dual drain plugs and high pressure 20psi radiator cap included
  • Plug and Play on NA/NB and OEM fans (does not require purchase of $43 worth of adapter brackets like other crossflow radiators)
  • Lightest Miata high performance radiator
  • More race wins, lap records and national championships than any other Miata radiator in the world
  • 5 year warranty – longest in the industry

Why crossflow? The Crossflow utilizes a side to side coolant flow pattern. The OEM and most aftermarket radiators have a downflow top and bottom tank configuration. The primary advantage of a crossflow is the longer transverse coolant path allows more time to shed heat. Placing the filler on the low pressure side also prevents the cap from releasing pressure prematurely as it can in traditional downflow designs. The core also features carefully optimized fin density and thickness to allow the maximum cooling in the most compact and lightweight radiator. This lightweight 31mm core will cool more efficiently than the Koyo 55mm once offered and weighs about 40% less.

Why OEM fans and shroud? Our street and track testing shows that the amount of air entering the nose of a Miata above about 20mph is far higher than any fan can move. For this reason, we do not recommend any aftermarket fans or shrouds as some street oriented tuners may suggest. At any speed above 20mph, a shroud will actually reduce total air mass through the radiator. If you only need to hardpark or sit in an autocross grid with the A/C on, then shrouds will help. If you need it to run cool at speed, do not use an aftermarket shroud. We use the stock primary fan on all our race builds and have never run out of cooling.  A typical Miata will need to sit and idle however, so the single OEM primary fans is needed for that. * Use this top hose if you do not have a Coolant Reroute            DOWNLOAD INSTRUCTIONS

More details on the design
-Two drain plugs. Each drain plug is a common 10×1.25 bolt with a simple o-ring. Lose a plug? 10 minutes at your local auto parts or hardware store and you are back in business. Other radiators use proprietary plugs that are only available from the radiator manufacturer. This honest ease of use is intentional in every aspect of the design.

-High flow fill neck. Nothing more annoying that bleeding a cooling system that has a tiny filler neck that requires a funnel and slo-mo filling.
-High pressure 1.4 bar (20psi), high temp cap. The standard cap with our radiator will allow your system to operate at 25% higher system pressure. That raises the boiling point even fur
-B tube core. The B tube is actually two tubes in one. The B tube has a septum, or divider that runs down the center of each tube. This increases the surface area and help to equalize the wall pressures inside the tube to further optimizing cooling efficiency. Our core is one continuous tube, not two cores sandwiched like you might see in other large capacity cores. This means maximum surface area with minimal external size/weight.
-High fin density. Our core is 19.5 fpi, or fins per inch. Our testing has shown that 18-21 fpi is the sweet spot given the airflow, temp deltas and water pressure of  Miata system. -Compact 6.5mm fin height increase coolant to core contact area -Convertible. Our radiator will fit any year 89-05 MX5 Miata with included hardware. –
-Light weight design. 7.8 lbs, the lightest aftermarket aluminum radiator available

Want to learn how to maximize the performance of your entire cooling system?  Learn more HERE