Comprehensive E-Fan Thread

[DenaliHD66]

I hope my search isn't broken, I did look around and just saw a lot of short, dead-ended threads regarding E-fans and fan clutches. Can we start a thread that has all the options for direct fit/aftermarket/etc. electric fan kits and other solutions to OEM fan clutch?

I've seen some guys with those tan-colored fan blades... who makes them and are they supposed to be extra lightweight or something? Is there a performance gain to be had from them, or is it better to just get an E-fan?

Has anyone used this in their trucks? These seems to be the most powerful e-fan setup I've seen that [allegedly] fits our trucks. Its expensive though.

Flex-a-Lite Automotive Dual 13 1/2 inch electric fan system with full shroud

 

[jaguarjoe]

That Flex a Lite fan is interesting. At the top of the add the fans are 13.5", at the bottom of the ad they're 15".

$634 is a rip off. In my experience with Flex a Lite, their fan motors are crap. Ditto for anything made by Imperial. A variable speed fan is only effective with a PID controller behind it.

I did the E-fan thing to my V-12 Jag. I bought 2 GM F37 fans for $20 at the P-n-P, spent about $25 for parts to make a redundant dual temp controller, and spent about $75 for a custom designed and fabricated to fit shroud. It's been working well for about 10 or 11 years now. The only change I would make would be altering the speed of one fan so the both fans do not run at almost exactly the same speed. When they run together, the fans beat against each other and you can hear the drone inside the cabin.

 

[DenaliHD66]

Interesting. I found the same set of fans for 100 bucks less, but still very pricey. I like the sleek compact design of PCM4LESS's e-fan kit, but I hear both good and bad reviews about it. Will I need to get a larger alternator if I get an e-fan? Is it even possible to fit a larger one in our trucks?

 

[BoldAdventure]

I have to say, you should read this: OffRoad TB - View topic - Cooling System Upgrades Part I: Fans very comprehensive.

Antihistamine follow up on radiators is very comprehensive too: http://forums.offroadtb.com/viewtopic.php?f=27&t=4007

 

[DenaliHD66]

Those are great reads. So much to consider. I just want a setup that turns both fans on when it needs to, and maybe a manual switch to toggle them between off/50%/100% from the cab.

 

[Mooseman]

I guess you haven't seen my thread?
http://gmtnation.com/f24/my-electric-fan-setup-montana-venture-efans-2425/

A couple of options in there for controllers, the last one from Jegs looks interesting.

 

[DenaliHD66]

I had been set on going with the PCM4LESS fan setup, but that aluminum shroud seems to block out the flow from the air through the radiator. Is it seriously a solid piece of aluminum with a fan on it? I'm not a big tower/off roader, and I don't live in a hot climate, but I don't wanna have to think about whether or not I'm going to be cool enough. Like the guy in that long thread stated, he spent some more to get the nice dual-fan setup and quality controller with manual toggle switch. I think I'd rather have that?

 

[BoldAdventure]

I had been set on going with the PCM4LESS fan setup, but that aluminum shroud seems to block out the flow from the air through the radiator. Is it seriously a solid piece of aluminum with a fan on it? I'm not a big tower/off roader, and I don't live in a hot climate, but I don't wanna have to think about whether or not I'm going to be cool enough. Like the guy in that long thread stated, he spent some more to get the nice dual-fan setup and quality controller with manual toggle switch. I think I'd rather have that?

That actually pulls the air flow thru the whole fan. The fan doesn't blow air on your radiator, it pulls air from the front side and out, by having a cover like that, it creates a vacuum. Vacuum lowers the air pressure and in tern cools better. Remember air is going in the front of the vehicle and over the blades of the radiator, the fan helps to pull that air at greater volume.

 

[Mooseman]

The problems with the PCM4Less setup is twofold. The first is that it is a flat piece of aluminum and the fan will only pull air through the radiator mostly directly in front of the fan. That flat piece does nothing to help the fan pull air across the whole radiator. The second problem is that same flat piece will not allow air through it except through the fan. At cruising speed, this will not be enough to cool the engine making a ton of heat.

In comparison, these Derale 16837 Derale High-Output Dual Fans are dual fans, have flaps to allow air through while cruising and are set back to pull air across the whole radiator.

 

[DenaliHD66]

That actually pulls the air flow thru the whole fan. The fan doesn't blow air on your radiator, it pulls air from the front side and out, by having a cover like that, it creates a vacuum. Vacuum lowers the air pressure and in tern cools better. Remember air is going in the front of the vehicle and over the blades of the radiator, the fan helps to pull that air at greater volume.

Well right, but the concept is like putting up a wall between the radiator and fan... so the engine is denied the natural air flow. No air is pulled across the radiator.

The problems with the PCM4Less setup is twofold. The first is that it is a flat piece of aluminum and the fan will only pull air through the radiator mostly directly in front of the fan. That flat piece does nothing to help the fan pull air across the whole radiator. The second problem is that same flat piece will not allow air through it except through the fan. At cruising speed, this will not be enough to cool the engine making a ton of heat.

In comparison, these Derale 16837 Derale High-Output Dual Fans are dual fans, have flaps to allow air through while cruising and are set back to pull air across the whole radiator.

Yeah kinda thought so. The problem could be alleviated by just cutting out the aluminum panel but why do that when the latter seems to be a better option.

 

[jaguarjoe]

Cutting out the aluminum panel without flaps would cause some or all of the fan's air to bypass the radiator by sucking air through the cutout instead of the radiator.

I would like to know how these fan CFM's are calculated. It takes HP to pull 4000 CFM. That's probably free air CFM so flow would be a lot less behind a radiator.

Does the TB have rubber foam wrapped around the perimeter of the radiator to force all of the air entering the grille to go through the radiator? I know the shroud is not sealed against the radiator, doing that would help too.

Every little bit helps.

 

[BoldAdventure]

Well right, but the concept is like putting up a wall between the radiator and fan... so the engine is denied the natural air flow. No air is pulled across the radiator.

Yeah kinda thought so. The problem could be alleviated by just cutting out the aluminum panel but why do that when the latter seems to be a better option.

GM must of thought it was a good idea when they built the shroud that goes around the fan in my corvette...

 

[DenaliHD66]

In the cold winter months, could I just remove my fan clutch (assuming I had the patch for the code)? Just curious if it would actually overheat in the cold winter months.

 

[Conner299]

In the cold winter months, could I just remove my fan clutch (assuming I had the patch for the code)? Just curious if it would actually overheat in the cold winter months.

I may be missing something... But wouldn't the fan clutch be non existent, if you had e-fans? Or are you trying to have both mechanical and electrical.

 

[Mooseman]

In the cold winter months, could I just remove my fan clutch (assuming I had the patch for the code)? Just curious if it would actually overheat in the cold winter months.

Yes you would overheat when you would be stopped idling or at a light for an extended period of time. Still needs moving air despite the cold.

Edit: My efans come on in winter too when I'm stopped albeit less often.

 

[DenaliHD66]

I may be missing something... But wouldn't the fan clutch be non existent, if you had e-fans? Or are you trying to have both mechanical and electrical.

Just asking if I had neither if I still would overheat.

 

[marshall@pcm]

Unless you kept moving...eventually, yes.

 

[DenaliHD66]

So I've really been leaning towards getting the Flexalite 295. It seems to move the most air, and you can toggle between 60% and 100%. I thought about the inability to shut it off at will, but I guess that can be answered as a safety reason. These fans come with everything you need and seems just like a plug and play basically. Might have to fabricate some mounts to make sure it fits on properly. Anyone else use this fan set or have any other input?

 

[jaguarjoe]

The first Efan I put in my Jag was a flexalite. It lasted about 6 mos. then the field magnet broke into a bunch of pieces and trashed the rest of the motor. Armed with dimensions, I scoured the P-N-P where I came up with a pair of GM F-37 fans. They have worked great for years.

 

[Mooseman]

And that Flexalite 295 is $520. Way too pricey for me. $17 for a U-Pull-It dual fan and $130 for a Derale controller, maybe another $20 for relays, wire and misc.

 

[Mooseman]

Double post

 

[DenaliHD66]

Jegs has the Flexalite 295 for $499. Either way, I don't know what I'm doing and I want something that will actually cool. Apparently single electric fans are not capable enough... but I'd be getting the HO alternator, so this would be a $750 project. Would be fun but I'm not sure I wanna drop that into my ride that is worth about $8-9k right now.

 

[jaguarjoe]

You have had the $500 Flex a lite on your mind since the first post here but, another P-N-P option is a mid 90's Ford/Lincoln "monster fan" it is a two speed single fan which moves a ton of air.

 

[DenaliHD66]

Might need to do the upgrade sooner than later... fan ticking is getting pretty loud.

 

[Mooseman]

Here's what I recommend if you only want to go with new parts:

Derale 16837 dual fans, $272
Amazon.com: Buying Choices: Derale 16837 Dual Radiator Fan with Aluminum Shroud Assembly

Jegs Controller with dry sensor, makes for a simpler installation:
JEGS Performance Products 52126 JEGS Adjustable Dual Fan Control Kit with Dry Temperature Sensor

This would be the simplest and cheapest option. No low and high. Just fan 1 and fan 2. When the first temperature is reached, fan 1 will come on full. When it reaches the second temperature, fan 2 will come on full.

Oh, and that Flexalite setup you're so hung up on uses a radiator push probe. In my experience, not very good at controlling temperatures and is very finicky.

 

[DenaliHD66]

That dry temp sensor is interesting. I thought the flexalite one would tap into the water housing? I know PCM4less e-fan does. If anything I'd want it to be simpler than that, and just have both fans operate at the same speed all the time. I'm fine with like 50% and 100% but each one coming on and off I'm not sure about that..

I guess it takes away from the load for turning both on at the same time, but I was already planning on upgrading the battery cables and putting in an HO alternator. How well does the LS1 setup work?

 

[DenaliHD66]

So I'm back to thinking about doing this mod again. I'm on the Derale fan kit, but I'm trying to find the best option for fan controller. I don't need something with variable control, just on/off. The temp probe in the radiator and dry temp sensors are OUT as options. Are there any that take the place of the stock thermostat?

 

[Mooseman]

Well no because you need the stock temp sensor. I have seen this one that taps into it though:
Electronic Fan Controller 70 Amp

The only down side with this one is that it can't be exposed to the elements.

 

[DenaliHD66]

Hmm I want something that I won't have to worry about getting wet and what not. I don't want to do a lot of fabrication either.

 

[Mooseman]

If you're doing efans, there will be fabrication

 

[DenaliHD66]

So, what exactly is so bad about the PCM4LESS fan setup? It seems to be the most cost effective and simplest to install.

 

[Blckshdw]

So, what exactly is so bad about the PCM4LESS fan setup? It seems to be the most cost effective and simplest to install.

As previously discussed, there was the issue about airflow at cruising speeds. From a more recent post, I know that PCMofNC has added cutouts on the sides of the shroud with flaps to address this. The other issue was the close proximity of the shroud to the radiator, causing the cooling/air flow to be focused directly in front of the fan, instead of across the entire radiator. I haven't seen what kind of clearance the initial shrouds had, or what the current ones do, so I can't really comment on that.

One of the members here has the older setup without the flaps, and he hasn't had any noticeable problems. He doesn't have the ability to read real time data, but his dummy gauge sits happily at 210, so it can't be all that bad.

 

[xtitan1]

As previously discussed, there was the issue about airflow at cruising speeds. From a more recent post, I know that PCMofNC has added cutouts on the sides of the shroud with flaps to address this. The other issue was the close proximity of the shroud to the radiator, causing the cooling/air flow to be focused directly in front of the fan, instead of across the entire radiator. I haven't seen what kind of clearance the initial shrouds had, or what the current ones do, so I can't really comment on that.

One of the members here has the older setup without the flaps, and he hasn't had any noticeable problems. He doesn't have the ability to read real time data, but his dummy gauge sits happily at 210, so it can't be all that bad.

Maybe this is a dumb question but if you can't tell the difference what's the point in doing this? Less alternator drain and better access to the belts on the engine or something?

 

[Mooseman]

Maybe this is a dumb question but if you can't tell the difference what's the point in doing this? Less alternator drain and better access to the belts on the engine or something?

Efans actually add load to the alternator but only when they are running. I'd say that there is less parasitic friction losses and less stress on the water pump bearings. It does clean up the engine bay.

Sure, I drink the efan Koolaid but I like my setup. I know that on the TV show Trucks, they did replace the viscous fan with an efan on a full size Ford truck and gained .7 hp on the dyno. OK, not a tire smoking gain but still something (which is more than any CAI!). And I just didn't want to continue using the failed electro-viscous fan technology. You could also get a tune to get rid of the fan error codes and run an 08 viscous fan.

 

[AtlWrk]

Efans actually add load to the alternator but only when they are running. I'd say that there is less parasitic friction losses and less stress on the water pump bearings. It does clean up the engine bay.

Sure, I drink the efan Koolaid but I like my setup. I know that on the TV show Trucks, they did replace the viscous fan with an efan on a full size Ford truck and gained .7 hp on the dyno. OK, not a tire smoking gain but still something (which is more than any CAI!). And I just didn't want to continue using the failed electro-viscous fan technology. You could also get a tune to get rid of the fan error codes and run an 08 viscous fan.

Biggest advantage IMO: never having to wrestle with the fan clutch nut and that $#^&ing fan shroud ever again.

 

[DenaliHD66]

Okay so the PCM4LESS one doesn't direct airflow well enough. Other thing is, I have an external tranny cooler installed now, so that may impact flow even more (?). What's the difference between the 08 fans and older? Controlled by the ECU?

 

[Blckshdw]

Some discussions about the differences in this thread. Start with post #2

http://gmtnation.com/f23/cooling-fan-clutch-decision-8679/

 

[bobdec]

Post #2 did not cover the 08-09's....recapping.. . 02-05 had original problematic design PCM controlled clutch, 06-07 had newer design PCM controlled clutch (can be used in 02-05's) , then with the '08-09's they dumped the PCM controlled clutch and went a thermal clutch. Thermal has no electronics activates mechanically when radiator air hitting the clutch reaches a specific temperature. Back to the 80's design. Not as efficient as the fan will run more often..but less service complaints.. Just MY Opinion they saw product line ending in 09 and threw a true and tried thermal clutch in there to sunset the product line.

 

[DenaliHD66]

Spoke with a flexalite rep today about the 295 fan. The controller it comes with controls both fans at the same time. They can be programmed to come on, say 180 degrees, and at 60% power. Then another set temp and they go up to 100% power.

 

[jbacklund]

Spoke with a flexalite rep today about the 295 fan. The controller it comes with controls both fans at the same time. They can be programmed to come on, say 180 degrees, and at 60% power. Then another set temp and they go up to 100% power.

I have the Flexalite fan controller and it's working great and came with good instructons. The feature to let them come on gradually is also nice to not load the alternator too much instantly. I really recommend it.

I think the most important thing is to find fan(s) that can five you enough mass flow under all situations. I've experienced that my cheap fans don't pull enough during heavy load or hot summer days at no forward motion.

I put my sensor in the coolant tube with and adaptor between radiaor and t-stat. I think Flexalite sells one of those as well.