Mazda Motorsports identified a need for a better-performing radiator for Spec Miata. For this, Mazda Motorsports turned to PWR, which has long provided advanced cooling technology for NASCAR, IndyCar, and IMSA sports car applications. Consequently, PWR turned out to be the ideal partner for developing a new set of Miata radiators for Spec Miata, which will also work well for NB racers competing in other categories.
PWR didn’t just take an existing core and slap some mounts on it to make it fit. It was a research and development process that transformed the radiator from a single-pass design to a triple-pass design, enabling optimal function in the Miata.
We found years ago that Miatas like a triple pass. In a triple pass, we install a baffle approximately six inches below the inlet, allowing the coolant to pass through one-third of the system, then it flows back in the opposite direction. There’s a baffle about six inches above the outlet, so there’s another pass, and then the last pass will be the bottom third of the radiator. The water passes through one-third of the core three times. It separates the radiator into three smaller radiators.
This process enables heat transfer through three distinct cycles, rather than a single large process. The duct work and nose openings are critical in these cars, and it happens that the last pass is at the lower area of the grill, where it gets the most airflow across that particular part of the radiator. That’s one of the big reasons a triple pass works so well in this particular application.
The radiator utilizes PWR’s proprietary extruded tube race core and fin design, which works in conjunction with the stock fan – a Spec Miata requirement. It’s a direct replacement for the stock radiator, requiring no modifications. It also incorporates a couple of other unique features.
It may seem small, but we extended the top plate to help direct airflow (NB version). That’s something that’s not on the stock radiators. We also incorporated a zinc anode, which will help reduce the potential for corrosion.
0000-01-5502-CR (NA-90-97)
0000-01-5503-CR (NB 99-05)
To order, log on to the parts store or call (800)435-2508.
Pricing is subject to change.