Stage 2 brushless airflow kit
Stage 2 brushless airflow kit
What does it fit?
What does it fit?
Brushless? Why haven't you seen that elsewhere? These fans aren't usually available to the aftermarket, they're used by OEs and the military. Our long-standing relationship with Spal and our ability to create a complete solution means we can bring them to Miata owners!
So what's the advantage? First, the fan has a variable speed and an intelligent controller so it can deliver as much or as little airflow as required, from a slight whisper to a hurricane. It's tied into the coolant temperature, so it can anticipate problems and prevent the car from getting hot in the first place. This means less electrical draw and more power available at the wheels when the car is at normal temperature. It also avoids a big startup surge that can drag down your electrical system for a moment or blow fuses. In fact, it's so subtle you may never actually notice when they're running most of the time.
Where they really shine is their ability to pull through multiple heat exchangers. Most fans are rated at zero (not even atmospheric*) pressure, which is completely irrelevant. You have a radiator and maybe an intercooler and possibly an AC condenser and maybe even an oil cooler all stacked up in front of the fan, so it's having to pull hard to get air through that stack. A standard radiator will give about 0.5 inH2O of pressure at the fan and it only goes up from there. You can see from the chart how our brushless kits stack up. These motors are strong. They're also built to military specifications, so they're highly waterproof and vibration resistant. Naturally, it's mounted on a custom shroud with bypass flaps. The bypass flaps allow us to take advantage of airflow coming in through the mouth of the car (allowing the fan to spin slower or not at all) and decreasing the restriction of the shroud if the incoming air is greater than what the fan can pull.
So what's with the single fan variant? Well, by going with a single fan we can also go with a large diameter fan. These high-torque brushless fans are quite deep, and the central location of the single fan helps quite a bit with fitment. It also cuts down the cost fairly significantly. When we looked at the numbers, we saw that it slotted really nicely in between our Stage 1 kit and the Stage 3 - so our single fan experiment became the Stage 2.
This kit will fit with "normal" installs of our turbo kit and front sway bar, but if you have extra / bigger parts in front of the engine (e.g., a giant sway bar) it's a good idea to check clearance. This fan is about 2.25" (measured straight / horizontally back) from the fan mounting bosses at the sway bar. It's mounted at an angle, so it's a bit less at the bottom and a bit more at the top.
This airflow kit will not work on cars with the factory Mazdaspeed intercooler piping. This kit will also not work with factory intakes that have resonators hanging off of them - basically, if anything is close (horizontally) to your existing fans this kit will very possibly interfere. Bear in mind that this kit protrudes the same distance from the radiator in all places (as opposed to stock fans that have good clearance top and bottom but are deeper in the middle). Please reach out if you have any specific questions and we'll make our best guess.
Certain ECUs such as the Hydra and MS3 can control the fans directly so they do not require the standalone controller. Stock ECUs, MS2 and the FM221 will require the controller ("brain kit"). The fans will not work without PWM control of some sort. Please note that if you need the brain kit, you also need a place to mount its sensor (3/8" NPT hole) - our hose splice kit below is an easy way to add a hole for the sensor.
Fitment on a turbo car without a coolant reroute will be challenging and will require modification of the shroud and very tight packaging. We strongly recommend using this fan kit on a car with a reroute.
The non-crossflow variant is designed to fit an NA radiator. If you're going to fit it on an NB radiator with the horizontal fan brackets at the bottom, you will need our adapter kit (09-56956, please search on our site). The crossflow version does not need these brackets.
*Fans are rated at "not even atmospheric" pressure? What? Yeah. When a fan is rated at a certain CFM at zero pressure, any pressure that the fan has to work against is evacuated from the test chamber. Put another way, the fan is literally 0% efficient at that point. Your ceiling fan is working against higher pressure (atmospheric) than a cooling fan in that test scenario.
There are those who say that you don't need fans (or anything more than stock fans) or a shroud - and they're not necessarily wrong. If you only have a radiator (e.g., no AC condenser or intercooler), you have ducting to ensure almost all of the air entering the mouth goes through the radiator, improved evacuation (e.g., hood vents), and the car is always operated at speed, you probably don't need much or anything in terms of fans. However, if you have a stock body (no hood louvers, nothing more than basic ducting), and/or a stack of heat exchangers, you operate the car at slow speed (e.g., a tight track) or in traffic (whether on track or on the street), your need for improved airflow increases. Higher power, combined with the factors above, means you need that much more airflow from your fans as well. For example, NASCAR uses electric fans since they're typically in tight traffic, but F1 cars (with their typically cleaner air and infinitely-engineered airflow) don't. Also, bear in mind that we use bypass flaps to give the best of both worlds - minimal restriction from the shroud when the air coming into the mouth of the car is of a sufficient velocity, but proper sealing so the fan pulls across the entire surface of the radiator when the fan pulls more than what's coming in through the mouth. In a real world experience, on a turbo street car with AC on a tight track, this setup (as well as our Stage 3) allowed us to stay out about twice as long as any other fan setup.
Please note that a radiator is not included.