Electric Fan Conversion

[Pwnin O'Brien]

Now that my exhaust is complete, the next project I want to tackle is an electric fan conversion. I have read a lot of great things about converting to electric fans and I have also heard a lot of negative aspects of converting. I wanted to get everybody's take on the conversion and see if any NICO members have actually performed the conversion. Pics, tips, advice would be greatly appreciated!

I plan on going with a two-fan setup. I am not sure of the size of radiator so I can't yet say which diameter would work best. I am thinking two 12" or 16" fans should fit. Both fans will be wired to a controller (or controllers) which will turn the fans on around 180 degrees. One fan will also be wired to turn on when the A/C is on. One question I do have is is there such a thing as a variable speed fan, or is there simply on or off? Also, is there such a thing as a variable speed fan controller? It would be great if the fan didn't run at full speed when not necessary (say a 5 degree jump in temperature, the fan would run at 900RPM's, if the temp goes up 20 degrees, then fan would run at full 1400 RPM's).

[SnowSurfLax]

The one guy I know of who did it (not on this board) didn't like the outcome at all and went back to a stock fan as it worked better. He's a mod on other boards, so no worries about it being some amateur, he's often asked such technical questions as he's just about done it all.

As far as I know, no variable speed fans out there for a custom application like that. I think it's on or off.

[Pwnin O'Brien]

The one guy I know of who did it (not on this board) didn't like the outcome at all and went back to a stock fan as it worked better. He's a mod on other boards, so no worries about it being some amateur, he's often asked such technical questions as he's just about done it all.

As far as I know, no variable speed fans out there for a custom application like that. I think it's on or off.

Are you talking about a member on NPORA? I think I read what you're talking about a while ago. Do you have a link to the post or do you know why, specifically, he switch back to stock? Did the fans not pull enough air to keep the car at normal operating temperature?

My second option, if I don't go with electric fans, would be to upgrade the stock fan to a higher CFM fan, maybe a flex fan (something from flex-a-lite). My main concern is definitely cooling ability and my second concern is noise (plus, a flex fan is extremely cheap and can cool much better than the stock fan).

[fastpathy35]

ok just in case you dont read my post, the only time it overheated was when i had only one fan and i was sitting in dead traffic with the a/c on. so i bought a 10" also. not a problem since. i would highly recommend the electronic thermostat. it took me some time to find one but you dont have to manually turn them on like a lot of people who cheaply do the mod. the only aggrivating thing is people will ask whos car is running out in the parking lot or why did the car just turn on, as the fans turn off and on until the radiator cools off. it doesnt kill the battery and it doesnt dim the headlights or anything when they kick on. everything put together cost about $120. for the wiring, two fans and the electric thermostat. took maybe an hour to finish it all. wasnt hard at all.

[Pwnin O'Brien]

Well I did a little reading and research on the topic. It turns out that there are variable speed fans and fan controllers, flex-a-lite has a line of variable speed fans (sold as a pair with a shroud) which are 3300-6000 CFM's (I think that's for both fans, so about 1650-3000 CFM's per fan). I also read that in order to provide sufficient cooling, I would need at least 2800 CFM's of pull which would definitely require at least two fans. The problem: The flex-a-lite variable speed fans run about $500-$600 for the setup which is a LOT more than I intended on spending. I was really looking around $120 for the entire setup.

ok just in case you dont read my post, the only time it overheated was when i had only one fan and i was sitting in dead traffic with the a/c on. so i bought a 10" also. not a problem since. i would highly recommend the electronic thermostat. it took me some time to find one but you dont have to manually turn them on like a lot of people who cheaply do the mod. the only aggrivating thing is people will ask whos car is running out in the parking lot or why did the car just turn on, as the fans turn off and on until the radiator cools off. it doesnt kill the battery and it doesnt dim the headlights or anything when they kick on. everything put together cost about $120. for the wiring, two fans and the electric thermostat. took maybe an hour to finish it all. wasnt hard at all.

Your fans turn on randomly when the car is off? You don't have them to only be powered when the vehicle is running? That would be weird if I were standing by a vehicle and the fans just randomly turned on, I would be pretty freaked out. So your fans stay on for a little while after you turn off your car?

[fastpathy35]

yeah they kick off and on for maybe 30 mins after i park it. people always mention it but its almost as bad as people saying "hey your lights are on"...as if automatic lights havent been made for 20 years. i mean i appreciate the thought...

[fastpathy35]

oh and with the automatic thermostat, the fans are usually off during highway speeds because i hear them turn on at red lights or when i park. i highly doubt that a kit like what you're talking about would be all that great because my engine warms up within 2 miles of start up and theres not much time that you would need a slower speed.

[slickroger]

I have a somewhat weird question for ya, do you know the dimensions of the finned area of the radiator? I'm looking to do the electric fan conversion and I don't know the radiator dimensions and the max size fans I could mount to it.[/QUhttp://images.zeroforum.com/new/1/post.gif

Here is the bare Rad i measured and it was 19 7/8" x 28 1/4"

[Pwnin O'Brien]

Here is the bare Rad i measured and it was 19 7/8" x 28 1/4"

Awesome, thanks dude, it's greatly appreciated!

[W O T]

Youve got a 3.5 right Pownin?

Ive got 4 electric 12" fans sitting in my garage right now, and getting rid of that big a** fan would be pretty cool.

Im curious if the stock fan can be removed completely like that, any idea how it disconnects?

Pretty close to free horsepoweRRRR

[Pwnin O'Brien]

Youve got a 3.5 right Pownin?

Ive got 4 electric 12" fans sitting in my garage right now, and getting rid of that big a** fan would be pretty cool.

Im curious if the stock fan can be removed completely like that, any idea how it disconnects?

Pretty close to free horsepoweRRRR

Yeah, I have a 3.5...

It's just four bolts that hold the fan onto the fan clutch. The fan clutch is held to the pulley by four nuts. It's a twenty minute process to remove the stock fan (and ten more to remove the factory fan shrouds).


Modified by Pwnin O'Brien at 9:46 PM 10/14/2009

[Pwnin O'Brien]

Ok, so here is what I have found so far...

In order for an electric fan conversion to be effective, the total area which the fan(s) cover should be equal to or greater than 60% of the radiators finned area. Also, the fan(s) should be able to pull at least 2,800 CFM's total. Now, there is no way to know which fan to choose just by using the CFM value. However, using the magic of Photoshop, I was able to make a diagram of the radiator and the four possible electric fan setups. Each diagram below is an actual representation of the R50's radiator and all measurements have been reduced to fit on screen. One thing to remember, each fan will have larger dimensions than the fan blade dimensions, so a 14" diameter fan may actually require 16" or 17" of mounting space. The radiator dimensions (thanks to slickroger) are: 19 7/8" x 28 1/4"; area of radiator: 561.469 sq. in..

Four 10" FansFan area = 314.16 sq. in. = 55.95% of radiator area

Two 12" FansFan area = 226.194 sq. in. = 40.29% of radiator area

Two 14" FansFan area = 307.876 sq. in. = 54.83% of radiator area

One 16" FanFan area = 201.062 sq. in. = 35.81% of radiator area

So, from the above diagrams and calculations, it is easy to see that the best option is the four 10" fan setup. However, this is definitely not the most economical or the easiest to install. The next best option (which is a very close second) is the two 14" fan setup. I think that if both options pull the same amount of CFM's, there would be a negligible difference in cooling ability.

Now that I know what size I need, the only thing to do is find the highest CFM 14" fan that I can afford.

As for the fan controller, I will need to find the proper temperature to set the turn-on temperature to. According to the FSM, the factory thermostat should open at 170°F (76.5°C), meaning I should have the fans turn on at a temperature above 170°F; I am thinking that 180°F-190°F should suffice. I have also found out that the water control valve opens at 203°F (95°C); should I adjust the fan controller so that the coolant can get above 203°F before the fans turn on? Why is this temperature so much higher than the thermostat?

I like to do a lot of research on something before I buy it. I like to make sure I check all of my options and find the best one. I posted this information merely so anybody looking to do this conversion in the future can access all of the necessary information in one convenient spot.
Modified by Pwnin O'Brien at 11:02 PM 10/14/2009

[slickroger]

I'm sorry this may be dumb but I don't understand the reasons for doing this conversion.

Is the truck not better with the fan running all the time so its definitely cool?

and for all the Temps you stated it now seems you want the fans too cool it down when the engine temp is a little higher than the spec temp, is that not worse for the engine?

Just confused educate me so I can consider doing this mod aswell

[Pwnin O'Brien]

I'm sorry this may be dumb but I don't understand the reasons for doing this conversion.

Is the truck not better with the fan running all the time so its definitely cool?

and for all the Temps you stated it now seems you want the fans too cool it down when the engine temp is a little higher than the spec temp, is that not worse for the engine?

Just confused educate me so I can consider doing this mod aswell

Ok, this may be a bit long and boring...

So the factory fan is driven by the fan clutch. This fan clutch is controlled by the "ambient" temperature of the engine, as the engine heats up, a fluid in the clutch heats up and becomes more dense and allows the clutch to engage and turn the fan. As the engine becomes cooler (like on the highway), the engine will cool down and the clutch fluid will cool down and will disengage the clutch. Even though the clutch is disengaged, the fan will still turn, this is because even though the clutch fluid is cool, it still creates friction and turns the fan; this means that the fan is always turning. The belt-driven fan can be a very inaccurate and inefficient system, since it doesn't really use the engines coolant temperature to dictate the fan speed. So for example, your engine coolant could sharply rise to 200°F but the engines ambient temperature may not rise for another minute, so the fan takes a minute to catch up to the hotter engine temps. With electric fans, you can measure the coolant temperature immediately and the fans adjust accordingly. This allows for better coolant temperature stabilization. When you're driving around town, carefully watch your coolant temp needle, it will fluctuate ever so slightly.

Now, the main goal for switching from a belt-driven system to an electric system is to regain horsepower and to get better fuel consumption. When the clutch is fully engaged, it can require a lot of work to turn it fast, this is work that must be done by the crankshaft. Without a fan, the crankshaft doesn't have to turn some big clunky fan and it's work is much easier. An electric fan only runs on electricity, which does not require any mechanical energy and doesn't put any stress on the engine (since the alternator has the same rotational resistance regardless of the electrical load).

Let me know if that makes sense, it's a little late and my thought process is a little sloppy right now.

[Duckman540i]

When converting to an electric fan setup you are reducing the parasitic loss the engine gets from running the large fan clutch etc. This will free up the horsepower that was supposed to be there in the first place by reducing the load on the engine.

Benefits:

-Free up horsepower that was lost (10-12HP)-Better gas mileage (2-3 MPG)-Improved throttle response

[W O T]

I dont think you need to worry about how much area the fans take up on thesurface of the rad, just match or exceed the cfm's of the stocker.

How are you planning on getting the fans to turn on and off?

Ive got an electric in my Crx on a 1/2 size rad, but it simply turns on when the car is on, you seem to want it to work properly

[Pwnin O'Brien]

I dont think you need to worry about how much area the fans take up on thesurface of the rad, just match or exceed the cfm's of the stocker.

How are you planning on getting the fans to turn on and off?

Ive got an electric in my Crx on a 1/2 size rad, but it simply turns on when the car is on, you seem to want it to work properly

If you aren't gonna use a shroud with your fans then you have to worry about the surface area of the fans. The factory fan probably pulls somewhere in the neighborhood of 3000 CFM's, but since it uses a shroud it's able to evenly distribute the 3000 CFM's over the entire radiator. When you surface mount the fans, you can get hotspots if you don't cover all of the vertical races with the fan.

I'm probably gonna buy a dual electric fan controller or two separate electric fan controllers. I'll probably set the controllers to turn the fans on around 180°F. It'll probably take some experimenting to find the sweet spot. I also will probably wire one fan to always turn on (and stay on) when the A/C is on.

[slickroger]

How are you planning on getting the fans to turn on and off?

Ive got an electric in my Crx on a 1/2 size rad, but it simply turns on when the car is on, you seem to want it to work properly

Thats what I don't get. If your converting to electric why not have the fan on when the car is on like WOT said, would that not be the best setup for efficient cooling, and the power wouldn't matter because the alternator is running?

fastpathy35 says his turns on when the car is off why would you need that. I mean cant the car only get cooler when its off does it really need the fans help when not running?

Now depending on the size of fans you choose are you going to custom make a shroud for them is that easy? or is there somewhere you can get those?

Sorry for the questions Thanks for the answers

Heres the cellophane topic you asked about earlier in case you didn't see it

CLICK HERE
Modified by slickroger at 9:12 PM 10/14/2009

[Pwnin O'Brien]

Thats what I don't get. If your converting to electric why not have the fan on when the car is on like WOT said, would that not be the best setup for efficient cooling, and the power wouldn't matter because the alternator is running?

fastpathy35 says his turns on when the car is off why would you need that. I mean cant the car only get cooler when its off does it really need the fans help when not running?

Now depending on the size of fans you choose are you going to custom make a shroud for them is that easy? or is there somewhere you can get those?

Sorry for the questions Thanks for the answers

Having the fans always on is definitely an option, but this can cause your cooling system temperature to fluctuate wildly. This is not necessarily a good thing. When you start your car in the morning and when you're driving on the highway, your fan usually does not need to operate. If the fan is running, it may cool the coolant below the normal operating temperature which will cause your vehicle to run improperly (and likely cause the MIL to illuminate).

I think fastpathy35 just wired the fan controller to his battery instead of an ignition source. Normally the fans are powered by an ignition source so the fans only run when the vehicle is running.

Normally (if the fans are purchased separately) you mount the fans directly to the radiator. You can buy some kits which use shrouds, which are definitely better for distributing the air evenly over the radiator. Most fans come with universal mounting hardware, but do not come with the fan controller(s). Here's a pic of what I'm talking about on another Pathy (this is actually fastpathy35's Pathfinder)...

[W O T]

Having the fans always on is definitely an option, but this can cause your cooling system temperature to fluctuate wildly. This is not necessarily a good thing. When you start your car in the morning and when you're driving on the highway, your fan usually does not need to operate. If the fan is running, it may cool the coolant below the normal operating temperature which will cause your vehicle to run improperly (and likely cause the MIL to illuminate).

Naw man you cant "overcool" your coolant, Elec fans arent loud or anything, having them running when the car is on would be enough. Id buy some electrics and mount them on the front as pushers. But im in canada, I could probly run without a fan for the next 6 months its so damn cold up here.

I think I may just try this though

[fastpathy35]

lol i was reading through and thought to myself.."that pic looks real familiar." yes that is my pathfinder and i have a electronic switch the reads the temp that kicks the fans off and on wired directly to the battery. i mean i could very easily hook it to an ignition source but how it acts now doesnt bother me in the least. other than people asking why my car is running. they dont stay on very long and they only turn off and on for maybe 30mins. i have one 12'' and 10'' i dont see you getting much more than that. with the mounting tabs on the fans it get pretty tight.

[W O T]

Which fans you got?

[slickroger]

Are the mounts through the fins, did you have to squeeze a space through the rad to for every mounting device?

[fastpathy35]

yeah they are through the fins. be sure to use the springs and the foam pads. if not youll run into a problem i had with my mustang. the mounting tabs will rub through the radiator.

[fueler]

The one guy I know of who did it (not on this board) didn't like the outcome at all and went back to a stock fan as it worked better. He's a mod on other boards, so no worries about it being some amateur, he's often asked such technical questions as he's just about done it all.

yup that was xplorx4. he took it off cause it didnt cool as well as the stock mechanically-driven fan, even if he left the e-fan running 100% of the time.

its for sale if anybody wants it. not sure why you'd want to downgrade, though.

[W O T]

Do you have an idea or a link as to what fan he used though fueler, the thought of free horsepower just gets me horny, and my cars got plenty of juice for a whimpy fan

[Pwnin O'Brien]

So I'm resurrecting an old thread. I have been doing a lot of research on electric fans and I have found the holy grail of electric fans. I also found that the R50 radiator only has 27 5/8" of finned area, so two 14" fans was out of the question, but two 12" fans will work perfectly. The following fan can pull 3,300CFM with only 7.5 amps of current. My next project will be putting two of these on my radiator with a dual controller.

It's Perma-cool's 12" high-performance electric fan

[JonathanPrem]

Can someone do a write up on how to remove the fan and installing the fan with switch's.

please and thanks

[CanuckQx4]

did you ever install these pownin, I just checked out my rad setup and Id like to do this mod

I also think putting the ans on the front of the rad could save you ALOOOOOOOOOOT of room

any advice??

[01silvapathy]

If you do this PLEASE do a write up on what you did as im pretty interested in doing this mod