SOLVED E-Fan VS stock clutch Fan with FMIC
 

Ok so i build a new engine for my Fc. I use a 60-1 hybrid turbo setup. keep the A/c condenser, stock rad, and... mount a big Ebay FMIC behind the bumper and used a dual speed taurus E-Fan . ran the car. started tuning and found a that the efan was killing my voltage and the fuel pump was not able to keep up to fuel demands, so i bumped up the temps from 190f for the efan, so i bumped set point to 210F then 215F im on the highway doing 110km/h at night with ambient temps 73F, intake temps are 140F and efan is turning on and off while im cursing.... figured i need a new bigger rad. did some research found ppl saying to duct and plug any holes to allow all air to flow to rad. did this same prob. installed the stock clutch fan and shroud. took the car for a drive. O my the car is maxes out at 185F the odd 186F and drops as low as 175F. intake temp are as low as 100F now as well. See attched data logs :D
what a difference, plus no i find my engine bay temps are much lower(with i would have used my works remote temp probs to test temp difference) o well

(please note the high temp one yes im on and off the throttle as i could only access when efan shut off )
I just noticed you can actually see the T-stat opening on the log now

Im sure this horse has been flogged many times lol.
but figured id post some concrete numbers with true logs,

Disclaimer notes: all temp sensors used in this experiment were calibrated using ice water, boiling water and 100F water to give sensors there full range ;)

Well, kudos for posting some data but your timeline and methodology are kinda confusing.

Did you get a new/bigger rad or not and if so, when?
At your low ambient temp and speed (and, I assume, RPM), the car should have been running cool as a cucumber and yet you reached at least 217°. I'd figure your cooling package (including ducting) needs reevaluation, an opinion based on the significant drop in IAT.

I can see the water temp varying but the intercooler is first in line for fresh air, on the highway it is theoretically at least getting all it can drink. Your intake temp dropped a lot when the fan was constantly pulling and that means your setup is restricting airflow from behind the intercooler (which the fan helps alleviate). You achieve the same result- probably better- with an extractor setup on the hood.

Why didn't you address your subpar alternator before raising the fan trigger start temp?
Seems like that intentionally crippled the fan as it was still undervolted when it did start but with a greater heat load than before.

I did not upgrade the rad i kept the stock S4

I was wounderng about hood work as well. if the A:the stock TII hood was causing some sort of turbulance and or back pressure keep the heat in the engine bay sort of speak. an extractor would help Tones im sure.

I had 12V running the E-fan if i did not try to accelerate the car(as fuel pump is hungry for power!) i could see the voltage on the megasquirt, at times id see 11V but for the most part id see 12v(i understand its not the 14V it could see and 2V DC is big in a since, on an other note seeing as i could drive 110khm and not keep the car cool on its own that made me dig into rx7club.com and search efan set ups and found pros and most pros for stock fan, so i installed figured it was a simple enough tasks. the "subpar alternator" is or was a problem using the Efan, i did try the S5 alt with zero gauge wire all around to try and fix the voltage problems during E-fan use, but i figured if i can cure this problem with out spending any more cash then i need to Y not!

I do agree my setup is restrictive, the stock bumper was oddly enough not design for a big FMIC, i in theory should upgrade the front bumper to allow more forced air flow. but once more curing the problem by going back to stock fan for no extra cash spent. i have also left a 3 to 4" gap under the FMIC to try and flow more air to the condenser/oil cooler/rad when i installed the FMIC, not sure if this hindered my air flow but seeing as others have had the same problems i had im reluctant to think it is affecting the flow. could be wrong as i am most of the time hahah.

I do like your points tho. and are all valid!

this graph was an other day with lower fan set point, i believe it was set for 210F on and off at 203F its a tad more linear then the first pic with less heat load to remove but car still keep needing efan to keep setpoint.

I'm not sure I follow what's going on.

The car didn't cool down with the Taurus fan?

Then did with the stock fan?

As for the voltage issues, yes, sticking a massively inefficient piece of junk fan like the Taurus fan on a stock alternator is going to completely overload the system.

Bumper a limitation? I drive around all day in 30 degree weather with a stock S4 bumper, FMIC, Fluidyne rad and Pontiac 6000/Oldsmobile/Grand AM/GM 90s fan without temperature issues.

Yes I could not keep the car cool with Taurus fan even at highway speeds.
installed the stock fan and Temps never go past 185f in town or highway even with 30th days like this past sat

When installing a E-fan you really must upgrade from the sub-par 70A S4 or 80A S5 alternator. Try the 100A FD unit. You may even want to upgrade the cable from the alternator to the fuse box from the stock 6ga cable to say 4ga cable. You can then upgrade the main fuse from 100A to say a 120-125A unit.

The stock radiator, a/c condenser, oil cooler and a FMIC all add up to too much restriction to air flow as well as too much heat that needs to be rejection at lower speeds. You may want to start with a 180 degree thermostat and then select the e-fan controller settings accordingly.

Well, you'd clearly benefit from a reconfigured cooling arrangement as you shouldn't need any fan at low stress highway speeds.

But be that as it may, did you wonder how the efan would have done if you'd run it constantly like the clutch fan does?
After you'd fixed the alternator situation, of course.

really the root of your problem is the FMIC, they block too much flow to the radiator. V-mount configuration would be ideal. FMIC on an rotary, horrible combination

anyway the stock fan is probably more efficient than an e-fan, but its all tradeoffs. I would rather have inefficient efan and have easier to work engine bay. your comparison is not really fair because your alternator isnt up to the task of powering an e-fan

By any metric I can think of, the thermoclutch is LESS efficient than an efan.

efficiency maybe, airflow not a chance.

i've been through this debate a thousand times and ill toss a stocker on before ANY e-fan any day. that doesn't even touch on the fact that there is 100 things to go wrong with the electrical portion of an e-fan versus the 2 things that can go wrong with the stock thermofan.

Boy howdy, I'll tell ya, that efan requires a RELAY! and you practically need a doctorate to figger that sumbitch out.
And apparently, there are 99 other problems I haven't run into yet.

/me grabs the popcorn.

like a fan motor seizing, fuse holder melting, thermocontroller failing.. among other things.


yeah i've had just about every single thing fail that can fail in my car occur, and i'm not a complete tool when it comes to wiring electrical components. however there sure is a plethora of junk controllers and fans floating around out there.

kinda shitty when your $260 black magic fan locks and your water temps hit 260F before you notice it on a freshly built engine, stuck in the middle of traffic on a 108F day. i grabbed that bitch and spun it by hand until it kicked on enough to cool the car off enough to get on the freeway, where my temps were still creeping up. because no matter what you all say, you DO need a fan below 70mph if your intercooler is in front of the radiator, but you're welcome to test that theory on your own.

Agreed. Bang for the buck (bang being defined as reliability and 'cool-ability'), you're not gonna do better than a stock fan. Seems there are a number of forum members that are, for some reason, attached to efans, but I would assume that most would rethink things after an engine meltdown because a fuse blew or a relay died.

My takeaway from this is not to use a Black Magic fan, keep an eye on the water temp gauge and don't intentionally block the rad with other components.

I kinda like the efan because it actually responds to water temp and unlike the stocker, it cools just as well at low rpm as high.

I guess I just like living on the edge.

Well, I guess the bottom line is this...Both the efan and the stock fan have pro's and con's-figure out what works for your comfort level and your vehicle setup and roll with it.

yeah i know, i've also said the same thing in the past. but truth is no one watches their temp gauge 24/7 and it only takes 2 minutes to go from normal to about to explode hot.

the intercooler really had nothing to do with the fan failure though, simply exacerbates the issue of airflow issues that the FC has always been presented with.

in all honesty it's given me ideas to redesign my own V-mount that doesn't suck ass like the rest, using the space that no one utilizes.

im going to mount an intercooler on the roof

I worked on a car about a month ago (porsche...maybe) and the intercooler was under the car and parallel to the ground.

Well its been close to a week now and temps are keeping true to 185F. even on these humid 86F days we've been getting.
id like to see a dyo log of and e-fan vs stock fan and see the difference in hp if any. I might have to try that out when the car is tuned. (load on alt vs load from fan and clutch)


on that note:
i have seen 40amp relays cooked, bad contacts, coils dies, rusted/corroded water/condensation got in them. we used a 75$ thermostatic relay build for automotive use a while back when a friend and my self had FB's we placed the temp bulb in the rad fins worked ok for a few months till the fins got lose. so we installed them mounted to the rad hose but did not seance ok. instructions said we could insert them inside the coolant hose. so we did. my friend lost in sensing bulb inside the cooling system :0 and never found it haha. bearings on fan,
Cat stuck in fan blades... o wait thats the stock fan :D

and i have done the same, here is an RX8 i built with a V mount and all stock radiator with A/C.

it is actually flush with the bottom of the front bumper, the angle makes it appear lower than it really is. i'll probably work out something similar with my FC. and yes it was ducted and enclosed, this was just an illustration of mounting.

http://i60.tinypic.com/2z59imp.jpg

You guys make it seem as though at any second, by your very breath, the e-fan will take out your engine and family. I mean, my fuel pump is also an electric motor operated by a relay, and im still alive. I understand you guy's reservation for electronic things over mechanical, but : Stop being old, and the stock e-fan on the fc is still working for me. It should be dead by you guy's standards, but it still kickin.

whatever, e-fans have caused severe overheating several times for me even when i try to watch water temps like a hawk.

personally i dislike them, they have their place which to me is on a car that no longer can accomodate the mechanical fan.

^This Lion/Tiger hybrid speaks the TRUTH :D :lol:

Can't wait to see a v-mount that uses the mechanical fan, that should be....unique.

clokker gets very offended if you dont use an e-fan

Au contraire Rob, it's refreshing not to be the biggest Luddite in the room for a change.

The biggest issue with E-fan conversions that I have seen are folks that want to do it on the cheap with questionable or salvage yard parts (no offence clokker). Then to top it off they do not upgrade the electrical system to handle the added load. I upgraded my electrical system as noted above in post #7.

I am using a Flex-a-lite Trimline #116 fan mounted in the opening of the factory shroud along with a Hayden #3651 controller. I installed a Flex-a-lite #32082 sensor adapter in my upper radiator hose for the water temp sensor. The car has an all metal CSF radiator and I installed a Stant 180 F thermostat.

Here is how I did it the conversion a couple years ago;

https://www.rx7club.com/2nd-generati...hroud-1028539/

actually i think an OEM fan is better than the aftermarket, as Mr Lyger alluded to, the black magic fan, which used to be popular, is also a POS. my friend bought one new, and in like 1,000miles it had already been repaired 3 times, and the car had gotten hot 3 times, which is just unacceptable. (the circuit board fried, the motor seized, and then it caught on fire once too)

i also have happened to notice that the JDM tuners tend to stick with the stock fan, although when they do go E fan, they use the FD fans.

nope, i don't think all e-fans are bad. one manufacturer, a big one has really given me a bad taste and bias against them.

because you don't really think about the drawbacks until you're cooking eggs on your engine, and no amount of diligence can really avoid that possibility. i've simply never seen a failing mechanical fan cause such a dramatic failure scenario as a faulty e-fan can. even a loose clutch fan generally will only cause a mild and slowly built up overheat situation, a locked failure causes cool running but a major loss of engine power.

when i do run e-fans now i do use OEM junkyard fans. i won't waste money on big names, because of flex-a-lite.

and v-mounts don't use the fan, they use static airflow through the bumper as the rest of the cooling system uses the fan. so yes, it is also about the only v-mount configuration that you could use the mechanical fan with still.


i'm not at all saying an e-fan doesn't have a place on the car but i am saying if you have a problem with it, you have to consider if possibly losing your engine is worth it. i've seen e-fans turn to the flavor of the month mod on this forum but i've also seen plenty of people create issues that never were issues by doing them, adding another reliability factor to a car that already has a stigma.

EMS systems have engine protection if the coolant temp gets too high. In the event of a fan failure, limp mode or shut the car down.

Well, unless the ECU is old. Or a brand new Microtech. ;)

I'm just against that stupid Taurus e-fan. I don't know why it became a seemingly good choice, but just search all the problems that thing has caused. There are far, far, far better choices out that work perfectly without overloading the stock electrical system.

Any good fan will always suck up alot of energy. I have one from a quest and the stock alternator would barely hang on. When it was night, it just couldn't cut.
The way i see it, you should at minimum have a better altenator(fd or otherwise) before installing the e-fan.

The internet has made the fan famous, its crazy how popular it has become. Just google search taurus fan and you can read for hours

Could you tell us what these "better choices" are?

Hey!!! You kids get off my lawn!!!
 

There is no magic efan. Pretty much you get what you 'pay' for: more air requires more current draw. Less current draw=less air.

The crappy quality and high profile failures of some high dollar efans is appalling given the availability of inexpensive, durable oem fan units. Popular choices are Taurus, MarkVIII Lincoln, Villager, Volvo, GM etc. You completely get that, as you are also using oem fans from certain GM cars.

I currently have a Hayden 16" efan that pulls 16 amps on my TII mounted in a custom fiberglass shroud. 16 amps completely overwhelms the stock S4 alternator when I want to run my A/C. And I do- all the time and usually on high. It's air movement is just barely adequate for cooling the car with A/C running. In 107*weather recently it's proven to be not quite enough fan. So another Ford 3G alternator is going on another RX7 in my driveway. My shroud is designed to mount the Vulvo 2-speed fan. I have one on the shelf to try. I do not know the amperage pulled by this fan, but I will find out as I set it up.

The 'efan to end all efans' from the Mercury Villager was a total bust for me. It pulls less current on high than the Taurus does on low. Less air too. I could not use this fan on my N/A vert with A/C and get adequate cooling. Maybe this fan worked fine for thin stock radiators with no A/C?

The low-speed on Taurus pulls 15 amps. No big deal, I could handle that current on the stock S5 electrical system in my 90 vert. If I hadn't needed A/C, I would have been finished right there.
High-speed on Taurus pulls 25 amps. S5 alternator was no longer adequate for this additional load.

People have problems with Taurus fan because they can't wire, they don't understand relays, they don't run adequate wire size, they don't understand how to use temperature controllers etc. I also suspect that the Taurus two-speed wiring is confusing. You must not send current to both the low and high speed circuits. I personally had a learning curve with fusing the Taurus fan.

Some people have no A/C condenser and cooler climates. Any efan will do for them. Wiring is not as critical if your fan only pulls a relatively small say 10-12 amps. Some people have magic radiators and seldom even have their efan activate...(clokker :nod:).
Some of us however live in a hot, humid climate and want A/C. We have need of a real bastard-of-a-fan that can cool the turbo'd car and also dump the heat from A/C. Taurus and the Mighty MarkVIII fit this bill.

So, if efanbois will learn to wire a relay, or two, use adequate wire size and then figure out how to use simple temperature controllers, the Taurus fan won't be so frightening.

Aaron, do you remember the days when it was Gospel Truth from the old farts on this board that a N/A high compression motor simply could not be turbo'd without guaranteed certain disaster? *Someone* blazed the trail then others followed knowing it was possible if they stuck to solid principles.

Taurus efans are the same.


So don't be such an old fart about it.:lol:

Clutch fans move a lot of air at engine speeds.

Electric fans move a lot of air all the time.

Which is why I converted my car to electric fans. Note that I have yet to see an aftermarket fan that is worth its weight in used dogfood. I use OE fans.

If you're not wiring electric fans through a relay, with proper gauge wiring, well of course you're not going to have a good time.

My fans pull about 70a. Two dual-speed fans. Of course they are wired with 10g wiring and several high-current relays (was burning up the common 30a ones). But it pulls enough air that I can run the car on a dyno and finish a pull at a lower coolant temp than when I started. That is hardcore kickass airflow to be able to cool an engine off at WOT in real time with no vehicle speed. Which is what I needed, because my form of motorsport doesn't get much airflow but it does soak up tons of power.

I use an FC alternator. I also have an MSD (pulls big heaps current) and two fuel pumps. Voltage is not an issue except at idle because of the 3" crank pulley I have.

If a Taurus fan was causing charging system woes, something was wrong with the charging system or wiring.

Want an awesome single fan? Ford GT500 fan, 2013-up. (That is key, they were given a spec upgrade for 2013 and are an upgrade item for earlier models) You can buy them brand new from Summit for $200 or so. They're enough fan for a 600+hp engine with OEM-level expectations of noise, efficiency, reliability, and overhead. It is dual-speed with a resistor block built into the fan shroud, instead of two sets of motor windings like my Chrysler fans (and VW fans) use. There's a connector available from the dealer network if you don't want to use spade terminals.

It *looks* like it will fit on an FC radiator core just fine.

In all this discussion, yet to be mentioned is the shroud.
Which is all too often not even present; I see lots of builds with a fan slapped directly onto the core (using those gawdawful push through zip-tie things).

There is a formula (which I no longer recall) that uses the diameter of the fan hub to calculate how far off the core the fan should be mounted to minimize the dead spot under the hub and maximize the fan's efficiency.
Practically speaking, the further from the core, the better the fan will work.

Practicality is also a major reason I'm so fond of the Volvo fan controller.
It's easy to snag the relay and all the associated wiring from the donor and transplant it into your car, with very little modification. All the wire is appropriately sized and if you use the Volvo fan (which I am on the Z), after connecting fused 12v, you're basically done.

And, long as I'm bloviating on the subject, you have to use a real trigger switch, one that is in contact with the coolant.
NOT those stupid probe things you jamb into the core between the fins. Those things never turn on/off at the same temp twice and, just like the thermoclutch, are only guessing at the coolant temp.

Which is why I use a manual switch :) Adjustable switches all have far too wide an on/off range. Fixed switches are generally the wrong temperature for what we want. Manual switches are not difficult. You check your gauges every six seconds when you check your mirrors, right? So it is no problem. In reality I only turn on my low speed fan either in competition or when I want the idle to drop lower at a light. High speed fan is competition-only.

Please please PLEASE find me that formula! I have a "cooling woes" car at work and I keep saying we need to move the fans (which are shrouded) back away from the radiator so they can pull, and this is met with resistance "oh it doesn't matter, let's not waste time on that." Having solid formulas would help me greatly in my Cause.

Is it a clutch fan conversion like the FC? This "formula" works for me :nod:

https://www.rx7club.com/2nd-generati.../#post11399547

My info/data comes from the early days of watercooling PCs, long before you could just buy kits and slap em on.
The most popular radiator was the heater core from a '60s Pontiac Bonneville and aquarium pumps were about the only choice.
There were a couple of truly obsessive guys who extensively sensored their machines and then tried endless variations of fan config/speed, loop routing (video before or after the CPU?), etc.

Anyway, it was generally decided that you wanted the distance of the fan off the core to be between 1 and 2 times the diameter of the blade hub. Closer and performance decreased but further than 2 times away just stayed the same.


We don't have the luxury of such space. I couldn't mount my fan the theoretically correct distance of 6" because the engine is in the way.
Deacon's elegant solution is about as close to ideal as we can get.

BUT, it should be noted that data and conclusions from those experiments is not directly comparable to a car...your PC is (presumably) stationary and ambient temp is easier to control. Also, PC fans have much smaller hubs than our efans do.

It is undeniable however that moving the fan further away has a beneficial effect and is worth exploring if you have some space to play with.

Here you go.

Help me out.

Your *fans* pull 70 amps. You are using a stock FC alternator? Please clarify, because S4 outputs 70 amps, S5 outputs 80 amps. With either of these alts, you have not enough current available to run the engine or any other systems.

What is missing from the picture?

thanks

Jack

Jeez Jack, all that mathy/sciency stuff is very convincing.

It jibes perfectly with my explanation if the following minor correction is applied:

What I Said divided by cosine of What Jack Said equals What Jack Said.

Of course, to be fair, we were concerned with two different phenomena.
We were interested in minimizing the dead spot under the fan hub and you want to equalize draw over the shrouded core and I'm not sure the two are the same.
But as I said, I'm not sure how relevant my experience is to this example. Two 120mm PC fans totally cover the Bonneville core, the shroud was basically just four walls used to hold the fans off the core. The shroud was never going to be a restriction in the sense that some of it covered the matrix.

Your formula seems to definitively define a minimum distance but does not cover what might (or might not) happen as the minimum is exceeded.
It'd be sweet to put a thermal imaging GoPro in the cars nose, pointed back at the rad face and then do some tests.
I'd bet it shows a hot spot right where the fan hub is, a spot that would shrink, to one extent or another, as the fan is moved further from the core.

Whether it would make a tinkers damn to coolant temps, I don't know.
There are so many uncontrolled variables in a moving car in the wild.

Maybe the space contributes to the stock fan working so good

Someone mentioned the mustang fan, i like the flaps i think the flaps are key to highway performance. I think i would like to try one out

https://i.ebayimg.com/00/s/MTA2NlgxN...U3L99/$_35.JPG

If you note, the hub in my example is out about 30% further than the calculated minimum, so the area under the hub is flowing pretty well. If you want to be more precise, add the hub area to the shroud area and re-run the calculator.
Once you attain uniform face velocity across the heat-exchanger, you are pretty much done.

But there is more-I postulate that the angle of the air leaving the fan can cause turbulence in the engine bay, leading to increased static pressure under the hood and thus reduced air-flow through the radiator. That is why I have a 'weak' efan with a custom shroud. The shroud is fiberglass and fits my crossflow manifold perfectly. It stands the efan vertical under the hood, yet takes up far less space than the stock shroud. It also can be removed with the fan attached in less than 1 minute, including raising the hood.

70a is only a rating. I actually have a S5 alternator but it can put out 100 amps according to my amp clamp.