by Steve Rhodes ([email protected]) For those of us that want as much power as we can squeeze out of a lightly modified engine, or those of us with heavily worked engines, there is one upgrade that some consider essential for increased power, fuel efficiency, and temperature control. This is the concept of electric fans. But before I describe how my upgrade went, let's first look at the pros and cons associated with the upgrade: Overview The advantages of electric fans over stock fans are numerous, but there are some other things you might want to consider. First of all, the most obvious benefit is that you'll free up a few horsepower by not having the engine turn that big old fan, which
does practically nothing during highway cruising anyway. The car will also be quieter. Next, there will be more room in the engine bay to work on other things. Also, you can control exactly when the fan comes on, to allow your engine to run in a more specific range. And finally, you're much less likely to get a finger or two chopped off. However, the fans will exert a drain on the alternator (30 amps in my case). Also, one wiring mistake will cause a malfunction, leaving your car prone to overheating. And finally, mounting them can be difficult. Where Do I Find Them? There are several places you can go to find the fans. One place you can try is a high-performance catalog. You can find them in there with prices depending on the size, and the application for which you will need them; more powerful engines need more cooling. You can order either a large, single fan, or two smaller fans. Another place to try is the Junkyard. You can find these fans most often in third-generation F-bodies equipped with v8's. Depending on the car, it can either be a single, or twin fans. An unlikely candidate is a '90-'93 Chevy Lumina - that's where my twin fans came from. On most factory setups, there is a sender linked to the computer which tells the fans when to turn on and off. However, none of our cars HAVE a computer, so we need to do some simple custom wiring. Ebay is another obvious place to look for electric fans from factory third and fourth generation Camaros. In most single fan setups, the computer will tell the fan to turn on at a certain temperature, and off at another, and to automatically go on when the Air Conditioning is activated. In dual-fan setups, the primary fan goes on when it needs to, and the second fan is used when the car gets very hot, or when the a/c is turned on. Now That I Have Them, What Do I Do??? This part is much easier than it sounds. Trust me. I'll be using my 1980 Camaro as the example for the remainder of this article. Installation First, take off your fan shroud, and un-bolt your old fan. Replace the old bolts that held your fan to the pulley with shorter ones so the pulley stays on. Now for the toughest part - the installation itself. When I got my fans, I took the upper support for the fans as well. I cut about 2" off the bracket, and there were TWO holes that allowed it to screw right into the spots that the fan shroud screwed into, on the original radiator cover. It was almost too easy - just remember to measure everything out first. As for the bottom part of the fans, all I needed to anchor them down was a few pieces of tin, a drill, and some screws. Since the tin was light and easy to bend, I was able to make some custom brackets that did the trick perfectly. Now on to the wiring. Wiring This is a pretty straightforward procedure. You have to get power to the fans, tell them when to turn on and off, and then make sure they stay off after the car is parked so you don't kill your battery. You'll need some wire (12' of 24-gauge, 6' of red 8-gauge, 4' of black 8-gauge), a 30-amp auto relay (available at Radio Shack), blade-type connectors, blade-type fuse holder, and a B+M Adjustable Temp Controller. On my car, the Relay is mounted right near the battery. The relay is grounded to the car, and a 8" piece of 8-gauge wire connects the relay to the battery. That's where the power comes from. Then, use the 24-gauge to run from the ignition power lead from your radio or whatever to the relay to use as the trigger. This will mean that the relay sends out the power from the battery only when the car's ignition power is ON. Then, run some 8-gauge wire from the relay's output to the fan. BE SURE to put a fuse holder somewhere in-line here with a 20 or 30 amp fuse, depending on your application. I can't stress this enough. Then, on my setup, I have the fans grounded to the Tempereature Controller, which is mounted on the driver's side inner fender. This has a probe running into the upper radiator hose to detect how hot the coolant is. It also has an adjustable dial on it, so that you can set exactly when it turns the fans on and off. I believe that this is superior to the sensors that go in the block that make it go on at one specific temperature - a choice is better than no choice. I got mine for about $25 at a local speed shop. The Temperature Controller is finally grounded to my power steering pump bracket, completing the circuit when the car reaches the right temperature, but you can ground it anywhere. Some General Notes: We use the relay so that the fans can only go on when the ignition is on. Otherwise, the fans will sit there all day long cooling the car down after it has been turned off, and kill your battery VERY quickly. Trust me :-) Also, let me add that I've never had a problem using two v-6 fans on my v-8. Then again, my engine has very little work done to it. Larger, or more powerful engines might need a heavy-duty factory v-8 fan, or some monster aftermarket fan. Consult a professional to decide what fan you need. Don't wire the fans backwards, either. I've seen people do it, and laughed at them. The whole project took me one afternoon to do. Consider into that the fact that I had no idea how I was going to make it all happen, so most of that time was trial and error. I hope everyone who reads this can benefit from what I was able to figure out. All in all, you can probably gain 5 to 10 horsepower for no more than $100. Can't beat that. -Steve