Author: Ken Payne

In the quest for adding more power to our vehicle, we often overlook items which cause parasitic losses. Traditionally, trucks have relied on a belt-driven clutch style cooling fan. This system, while it does cool the engine to required levels in most situations, is designed first and foremost to be inexpensive to manufacture. These types of fans are heavy, and add significant drag on the engine resulting in lower fuel mileage and less power being delivered. Even with the factory’s fan clutch disengaged the fan is being turned (though to a lesser degree) by the engine, and a cold-started engine still spins the fan fast enough to prevent any sane person from wanting to try to stop the fan with their bare hands! In these belt-driven clutch style mechanical fans, the engagement of the clutch is controlled by a “thermistor” (a temperature-sensing device) that is placed in front of the clutch - a location where it is constantly subjected to a stream of hot air any time the radiator has any heat in it, which makes it run in many cases where it is not needed at all. Clutch failures can occur as well, resulting in a large amount of additional load on the engine at all times. In 2007, Ford changed to a PCM-controlled clutch fan mechanism in the F-150, but these clutches sometimes malfunction and when that happens, they stay locked at all times. Troyer Performance has reported numerous failures of these clutches in 2007-2008 F-150s during dyno testing, all with less than 8000 miles on the truck! When this type of failure occurs in a 2007 or newer F-150 with the PCM-controlled fan clutch, the result is a large increase in drag, resulting in losses of horsepower at the rear wheels of anywhere from a low of 26 RWHP to as much as 32 RWHP – additionally, the fans in the 2007 & newer F-150 are not designed to be spun at speeds greater than 3500 rpm, thus when the clutch fails this can also result in the fan experiencing catastrophic failure, and in a worst-case situation, literally come apart. These traditional belt-driven cooling fans are heavy. A typical belt-driven fan, depending on year, weighs between 9.8 and 12 pounds for trucks with plastic fans, and earlier model Ford trucks use metal fans which weigh even more! These Troyer Performance electric fans are much lighter, and are usually situated much closer to the radiator. The heavier the factory fan assembly, the more power and fuel mileage can be gained by installing the Troyer Performance Dual Electric Fan Kit. Additionally, a properly configured electric fan system will turn on and off as needed by temperature, whether the air conditioning is turned on, and is ultimately controlled by PCM command (which must be powered up and the ignition system turned on to supply power to the electric fans, preventing any possibility of the fans running with the engine turned off, so the battery is not run down). Installing the Troyer Performance Dual Electric Fan Kit removes all of the “parasitic” drag on the engine during any type of engine operation, freeing up significant power and improving fuel mileage, too – a win-win situation. The results are also measurable on a chassis dyno, with typical gains running from 12-15 RWHP and 15-20 lb/ft. of torque on 2004-2008 F-150s, and 14-20 RWHP (18-25 lb./ft. of torque) on 1997-2003 F-150s (depending on whether they have a metal or plastic fan). An important side note is that the difference between the electric fans and the factory 2007 & newer factory fan when it’s clutch fails is a whopping 26-32 RWHP. Troyer Performance has seen this type of failure happen numerous times and thus has been able to thoroughly document the results on their in-house chassis dyno. The actual “seat of the pants” feel (commonly referred to as the “butt-dyno”) depends on the weight of each individual vehicle – the lighter the configuration, the more noticeable it is to the driver, as the parasitic losses make up a higher percentage of power-to-weight ratio. This is not to say that electric fan conversion isn’t worth it in even the largest F150’s, far from it! For example, a typical 2004 F-150 with a 5.4 3V V8 engine with is rated at 300 HP SAE Net at the flywheel, produces an real-world average of 202-207 RWHP in bone-stock trim on an accurate load-bearing chassis dyno, such as Troyer Performance’s in-house Dynojet 224 LXC with eddy-current brake absorber unit. Installing the Troyer Performance Dual Electric Fan kit and increasing HP by a conservative 12 RWHP results an increase of 6% more power, right to the rear wheels! With a 15 RWHP gain, we pick up about 7.5% more horsepower to the rear wheels, as well as gain anywhere from a low of about 1.2 MPG to as much as 2.0 MPG, depending on actual vehicle weight, driving habits & conditions, and that’s the type of modification that everybody wants – more power AND better fuel mileage at the same time. The torque gains are even higher than the horsepower gains, and torque is really what it’s all about to get these heavy trucks & SUV’s moving and to save fuel. If your 2007 or newer F-150’s factory fan is sticking due to clutch failure (not uncommon), the power gain to the rear wheels is a minimum of 26 RWHP, which is a 12.87% increase! (Of course, if your fan clutch fails in the newer trucks, chances are you’re still under warranty and can get that fixed free by your Ford dealership, but this is just an example.) We installed a Troyer Performance Dual 16” electric fan kit in our 2006 Roush F-150 project truck, which is a loaded SuperCrew 4x4 with an approximate operating weight of about 6000 lb. The installation procedure is essentially same in all 1997-2008 F-150s (the primary difference being switched ignition source tie-in) and is very similar in all other model years of Ford trucks and SUVs. Troyer Performance has put years of research and development time into this quality dual-fan system. The advantages of this kit include: • Secondary fan turns on when the A/C is in use. Those of you who have experienced the less than ideal A/C cooling the factory system produces in rush hour traffic will appreciate this. • Custom fabricated electric fan mounting brackets. These eliminate the need for the plastic “zips” which most fans traditionally mount with, or the metal rods also commonly seen. The disadvantage of the zips or rods is that they require much more time to install and the final installation doesn’t look as clean. These custom fabricated mounting brackets give the overall installation a more professional look. • Uses a switched ignition source allowing power to be controlled directly by the PCM. • Dual fan controllers and temperature probes, one setup for each electric fan. This allows you to set the primary and secondary fans to turn on at different temperatures. • Heavy gauge controller wiring, not typically found in “off the shelf” applications found at your local auto parts store. • The ability to install LEDs to monitor the system. • The ability to manually control the fans. • Very detailed step-by-step installation article. • Elimination of the stock fan shroud, freeing up space and making it far easier to work under the hood, clean, etc. • Use of two fan controllers and two temperature probes provides complete dual redundancy. This system is in fact two complete cooling systems, so that in the unlikely event that a fuse is blown, or a fan or controller fails the system continues operate on its second fan, allowing the vehicle to still be driven! • All parts and supplies are included – no running around to parts stores looking for the finishing touches, as everything, including much higher quality split-loom tubing to finish off the wiring harness is included for a factory-installed appearance. Note that this article is not intended to be a step-by-step article for electric fan installation. Instead, its goal is to give you an overview of the steps involved, skills required and an estimate of installation time. First, assemble the two fans using the supplied custom mounting brackets and attach the mounting clips (see the arrows in the accompanying picture). The next step is to remove the radiator cover by removing the screws & threaded inserts. Note that for 2007+ the radiator cover is smaller than shown in this picture (2006 model F150). Remove the mass air-flow sensor and the factory air intake. Cover the throttle body with duct tape to prevent anything from falling in, such as dirt, hardware, tools, etc. (Because our project truck has a supercharger, we used photos from our archives of factory components where applicable in this article.) Loosen the fan body nut which fastens the factory clutch fan assembly to the water pump shaft by turning it counter-clockwise. With older Ford trucks, if the water pump pulley has ribs then the direction is usually reversed (clockwise) to remove the nut. Remove the fan shroud bolts on both sides of the fan shroud, near the top. While holding the fan assembly, finish loosening the fan nut to completely release the factory fan. Push the fan shroud back towards the engine, and lift the fan assembly out between the shroud and radiator, taking care not to damage any radiator fins. An extra set of hands is helpful here, but is not required. Now comes the installation of the completed Electric Fan Assembly onto the radiator. First, lower the assembly in place so the top mounting clips attach to the upper lip of the radiator. Adjust the top clips so the fans are close to the radiator without actually touching it, to avoid noise or vibration & rubbing, which is easily accomplished thanks to the fan depth adjustment provided in the Troyer Performance custom fabricated fan brackets. Tighten the mounting clips just slightly, do not fully tighten them yet. From underneath the truck, now we attach the lower mounting clips to the lower radiator lip and do the final adjustment to position of the fans until they are close to the radiator without actually touching it. The fan depth adjustment allowed by virtue of the design of these mounting clips is provided so you can adjust the fan spacing depending on the radiator thickness size (two different sizes of thickness on the F-150), another nice feature of the Troyer Performance fan kit. At this point fully tighten the top clips. Now we do the wiring, so the next step was to disconnect the negative battery cable. The kit comes with self-tapping screws for mounting the fan controllers on the windshield washer fluid reservoir. After lining them up and positioning where to install them, coat each screw liberally and the bottom of each controller with automotive silicone. This helps to protect them from corrosion. Mount the base of each controller where you previously marked using the self-tapping screws. Connect each electric fan’s black power lead to the corresponding fan controller power lead. Next, connect both electric fan motor ground wires to the power-steering bracket on the front cross member. Protect the wires with the supplied high-temperature wiring split-loom. Next, connect both of the Fan Controller ground wires. Remove the 11mm bolt from the inner fender (just forward of the battery), attach both ground leads and reinstall the 11mm bolt. Note: Some F150's have a nut here that fastens to a protruding bolt instead of a screw-in bolt. Connect and solder the fan controllers combined switched ignition source leads to the PCM’s harness as shown. Use the supplied heat shrink tubing to protect the solder point and then cover the Switched Ignition Source leads with some of the included high temperature split-loom for a factory-installed appearance. Attach the High Temperature Fan Controller’s green wire to the A/C compressor 2 wire lead. This accomplishes an automatic switch-on of the High Temperature Fan whenever the A/C is turned on, insuring the A/C system can provide maximum cooling even if the engine is too cold to allow the fans from normally turning on. This is a big help in cooling down a hot interior when the vehicle has been sitting outside the office all day, or anytime the vehicle is moving at less than about 45-50 mph, your A/C system will have increased cooling capacity. Carefully install the temperature probes between the radiator fins. Reinstall the radiator cover. Reconnect the battery. The final steps involve calibrating the Electric Fans to come on at the proper temperatures. When calibrating the Low Temperature fan, remove the High Temperature Fan’s fuse. Set the A/C control to the Off position inside the cabin. Start the engine. Closely aim an infrared thermometer at the radiator (or you can use a scan tool connected to the OBD-II port to read the actual coolant temperature as reported by the PCM). When the temperature reaches 180-185 degrees (F) at the radiator (or at 195 degrees if using a scan tool or tuner to look at the actual coolant temperature connected to the OBD-II port), slowly turn the Low Temperature Fan Controller’s temperature adjustment screw until the Low Temperature Fan comes on. Turn the engine off and let it cool for just a few minutes. Re-install the High Temperature Fan’s fuse and remove the Low Temperature Fan’s fuse. Start the engine and repeat the process, this time turning on the High Temperature Fan at a temperature that is ten degrees higher than where you activated the Low Temperature fan. Reinstall the fuses. This concludes the installation! The photos above are of the completed installation. Note how clean the installation looks. The arrows show how much space is freed up. Impressions and Operation During the bulk of most driving immediately after the installation the fans remained off. Only during prolonged idle and extended stop-and-go driving have I experienced the fans coming on, even during 95-100 degree weather. This indicates how much energy is wasted constantly turning the factory fan (even with the fan clutch). When operating the A/C, the High Temperature Fan comes on and the air coming out of the vents is ice-cold. Fan noise is only heard in the cabin when the windows are down and the vehicle is idling long enough for the fans to activate, and the level is just barely more than the engine’s normal noise level. They can also be heard just slightly when standing outside of the vehicle. During normal highway driving when accelerating to pass a vehicle, and on inclines, I noticed less throttle is required to achieve the same results. In city driving there is a noticeable bump in acceleration. It must be pointed out that everyone’s “butt dyno” is a bit different and thus their perception of the results on their individual vehicle may be interpreted differently, but the power gains are indeed there. When you eliminate the factory belt-driven fan, you will always gain horsepower and torque from no longer having to spin that heavy mass. Mileage is up about 1 mpg so far, and I have a feeling it will do even better as the weather cools off. I am pleased with the fans, the quality of the parts and the relatively simple installation procedure. The Troyer Performance Dual Electric Fan Kit has provided more horsepower & torque that I can feel in my SuperCrew 4x4, and I have seen an increase in fuel mileage. That type of result is the best you can ask for, and what these vehicles need.

(Copyright 2007 Ken Payne, All Rights Reserved. This article is used by Internet Brands, Inc. with permission - no license is given beyond this permission and may be revoked by Ken Payne.)

If your company is interested in sponsoring a product or service for this project truck please contact Ken Payne: ftsservice@gmail.com