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BLADES OF GLORY Choosing An Electric Fan For Your Off-Road Vehicle By Dan Sanchez Off-road racers and enthusiasts know that engine heat is always a big concern for their vehicles. Slow crawling over rocks and difficult terrain reduces airflow into the radiator, while driving at high speeds keeps engine RPMs high which produces more heat. In desert racing, there’s the element of extreme temperatures, and it all equals a higher chance for component failure. This is one of the reasons why electric fans are essential for both recreational and racing efforts. Most modern engines don’t use mechanical clutch fans anymore, as they often spin slower at idle and slow speeds and can’t create enough airflow to keep vital fluids cool. Electric fans have become the norm, but on off-road race vehicles and upgraded recreational vehicles, it’s important to know what type of fan works best as well as placement. The 3P’s - Push, Pull, And Placement Electrical fans are designed to push or pull air through a radiator or heat exchanger. Pull (or draw-through) fans are the most commonly used on engine cooling radiators as they won’t hinder incoming airflow when the vehicle is at speed. According to most fan manufacturers, pull fans are also the most efficient and provide the most amount of cooling capacity and airflow, but that depends on where they are mounted. It’s very common for pre-runners and race vehicles, to mount oil and transmission coolers at the rear of the vehicle due to space limitations in the engine compartment, and to add ballast to the rear of the vehicle. Because this area doesn’t get a lot of front air pressure when the vehicle is in motion, push fans are often used in these locations. The size of the fan typically depends on what they are being used on, be it a full radiator or smaller oil or transmission cooler. The idea is to cover as much of the surface area as possible. This can also be done with a shroud. “Ideally having a shroud is more effective than not,” says Andy Wagoner, president at Steele Racing Products. “That’s because airflow is much more productive when it’s being funneled-in versus just in the open air.” Without a fan shroud, Wagoner says you can compromise the amount of power the fan has to output to cool down a radiator versus one with a shroud. Be Smart Go Brushless According to experts, the best electric fans have brushless motors. Instead, they use magnets and have no parts to wear out. “The benefits include the fact that brushless fans have controllers and can change fan speed,” says Jack Anderson, C&R Racing Engineering Manager. “In hardcore off-road conditions, however, the controller can get too hot it can change the output of the fan. With coolers placed at the rear of the vehicle, pusher fans can cool themselves which is one advantage.” The next level is to take a brushless fan and upgrade the controller to a completely programmable microprocessor. “By doing this, you can provide logic to the fan system,” says Wagoner. “We can program fans to act under certain conditions, even to operate at specific speed intervals.” According to Wagoner these “smart fans” are being used in NASCAR, with teams such as Roush and Chip Ganassi. Aside from being turned on at different levels of power and temperatures, smart fans can look at engine functions and operate to cool accordingly. “You can also control fan speed based on track conditions and environment,” said Wagoner. “We can also set the system to accept other inputs from peripherals. These are popular with SCORE Trophy Truck racers and UTVs as they use aftermarket ECUs to control and monitor engine functions.” While smart fans are expensive and primarily used for racing, the challenge is to eventually sell to the average off-road enthusiast to use on their vehicles that can use a simple module to adjust fan speeds. Until then, off-road enthusiasts can take advantage of what electric fans have to offer their cooling systems, and benefit from a wide range of sizes and airflow that they can provide. SJ C&R Racing Steele Racing Products

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