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-   -   SOLVED E-Fan VS stock clutch Fan with FMIC (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/solved-e-fan-vs-stock-clutch-fan-fmic-1088232/)

immanuel__7 08-15-15 08:34 PM

SOLVED E-Fan VS stock clutch Fan with FMIC
 
2 Attachment(s)
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 ;)

clokker 08-15-15 10:42 PM

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.

immanuel__7 08-15-15 11:32 PM


Originally Posted by clokker (Post 11955692)
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?

I did not upgrade the rad i kept the stock S4


Originally Posted by clokker (Post 11955692)
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.

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.


Originally Posted by clokker (Post 11955692)
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 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!


Originally Posted by clokker (Post 11955692)
your setup is restricting airflow from behind the intercooler

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!

immanuel__7 08-15-15 11:49 PM

1 Attachment(s)
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.

Aaron Cake 08-16-15 10:04 AM

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.

immanuel__7 08-16-15 01:10 PM

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

DeaconBlue 08-16-15 10:09 PM

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.

clokker 08-16-15 11:03 PM


Originally Posted by immanuel__7 (Post 11955933)
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

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.

gxl90rx7 08-17-15 08:25 AM

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

clokker 08-17-15 08:42 AM


Originally Posted by gxl90rx7 (Post 11956224)
anyway the stock fan is probably more efficient than an e-fan, but its all tradeoffs.

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

RotaryEvolution 08-18-15 08:00 AM

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.

clokker 08-18-15 08:28 AM

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.

SirCygnus 08-18-15 08:30 AM

/me grabs the popcorn.

RotaryEvolution 08-18-15 03:37 PM


Originally Posted by clokker (Post 11956749)
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.

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.

freq 08-18-15 05:00 PM


Originally Posted by Lyger (Post 11956975)
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.

clokker 08-18-15 05:31 PM


Originally Posted by Lyger (Post 11956975)
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.

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.


Originally Posted by freq (Post 11957022)
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.

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.

freq 08-18-15 06:42 PM


Originally Posted by clokker (Post 11957031)
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.

RotaryEvolution 08-18-15 09:11 PM


Originally Posted by clokker (Post 11957031)
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.

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.

Rob XX 7 08-19-15 09:16 AM

im going to mount an intercooler on the roof

jjwalker 08-19-15 09:46 AM


Originally Posted by Rob XX 7 (Post 11957304)
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.

immanuel__7 08-19-15 02:48 PM

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)



Originally Posted by clokker (Post 11956749)
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.

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

RotaryEvolution 08-19-15 04:24 PM


Originally Posted by jjwalker (Post 11957311)
I worked on a car about a month ago (porsche...maybe) and the intercooler was under the car and parallel to the ground.

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

fc323 08-19-15 06:40 PM

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.

RotaryEvolution 08-20-15 07:21 AM

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.

GoodfellaFD3S 08-20-15 07:34 AM

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


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