Justin Fivella
June 19, 2013

More Power and Cooler Temps

Lets be honest, while the stock mechanical fan does an admirable job of keeping down coolant temps, it also saps power and sounds horrible as it whirls away. With our hefty dual-core highway patrol radiator and a new 180-degree thermostat in place, overheating was not an issue, but we wanted a cleaner look and max power from the stroker. A call to Flex-a-lite narrowed our search for the perfect electric fan.

Our coupe proved to be a difficult patient because the Vortech supercharger robbed precious underhood space. Between the V-3 Si head unit and the supplied crank pulley protruding into the areas commonly used for aftermarket aluminum radiators and electric fans, we had little room. Flex-a-lite stepped in with an ultra-slim, dual-electric fan setup that moved serious air.

Although we could've opted for a pusher fan in front of the radiator, generally puller fans mounted aft of the core are more efficient. Thankfully, the Flex-a-lite (PN 410) is a lithe 25⁄8-inch thick and easily slides between the blower and the large highway-patrol radiator. As anyone with a blown Fox will tell you, freeing up real estate is a blessing. Now we have better access to the belts and can make tension adjustments without having to remove the upper radiator hose.

Small additions oftentimes make the biggest improvements.

A pair of 12.125-inch, eight-blade fans move a combined 2,500 cfm, which is more than enough for our motor, even on the hottest of days. Flex-a-lite offers several different fan control modules, but we chose the variable-speed controller for its extreme versatility.

Unlike traditional controllers that kick the fans on 100-percent at a set temperature, the variable speed unit can be set to activate within a set temperature window. This means instead of suddenly bringing the charging system under a huge draw, the fans can be set to run at 60-percent capacity at a certain temperature and increase in speed until reaching 100-percent as the water temp rises. In many incidents, the fans will never reach 100-percent because traffic clears and you're able to move, or the given fan speed is enough to cool the car. It's a clever method of lessening the load on the charging system.

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If there's one thing Flex-a-lite prides itself on, it's the completeness of the kits. The (PN 410) kit comes with everything needed to push mondo air. In addition to the dual fans, shroud, and weatherstripping, it also comes with the aforementioned variable-speed box, along with all the mounting, wiring, and temperature-sending pieces.

To prove its worth, we hit the dyno at Advanced Engine Development (AED) in Shingle Springs, California. AED is one of the premiere Mustang performance shops on the West Coast, and has extensive knowledge of Blue Oval pushrod and mod motors. Owners Shaun Perry and Drew Wallace build some of the fastest Mustangs on the West Coast, and even offer some incredible custom mail-order tunes for the Coyote-powered Mustangs. Suffice it to say, our coupe was in good hands.

Much to our surprise, the electric fans freed up more power than we anticipated, 11 hp and 22 lb-ft of torque to be exact. Peak gains were impressive and broad, as bottom-end and midrange portions of the powerband showed over 10hp and 20 lb-ft improvement from 2,000 rpm to redline. Lets also not forget the fact an on/off switch can be hardwired to cool underhood temps while sitting in the staging lanes. As we all know, cooler temps mean more power.

While this month's mods weren't big-ticket items, it's proof that small additions oftentimes make the biggest improvements. Now with an accurate eye on our coupe's vitals, backed by an engine-saving failsafe and a slick set of electric fans, it's time to dive underneath our Smog-Legal Killer and build the drivetrain and suspension to match the mighty motor.