2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

swapping to an electric fan, good idea?

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Old 02-07-05 | 12:06 AM
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swapping to an electric fan, good idea?

i have a new 9 inch 1500 cfm laying around, and i was wondering if taking the stock engine fan off and replacing it with this would free up some hp/making reving quicker, or just a silly waste of time. i am running a 13b non turbo 1988i am also planning on getting a lite weight fidanza flywheel.
will the 1500 cfm fan be enough?
thanks for you imput guys.
Old 02-07-05 | 12:11 AM
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nope

2000 cfm min, 2500 recommended.

pat
Old 02-07-05 | 12:13 AM
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thx for the numbers pat, i know were i can get a fan identical to this one, would that work?
would the mounting location change?( from infront of the engine to infront of the radiator)
Old 02-07-05 | 12:21 AM
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I will soon enough post 3 different dyno results. One with stock fan. Second without fan, no electric fan. Third, with electric fan on (supposed electrical load on alternator). I'm dying to find out how much electrical load is on the alternator and how much hp the stock fan does take away. Just so people know, the run with out any fan will have a couple of air blowers in front of the car to have less factors (water temp) change from run to run.

Side note: I had a FAL e-fan on my NA, worked for a while, checked all wiring and trouble shooted over phone with a rep. Relay went out. I dont know if 3hp (at most) enough to risk over heating the engine. We all know what happens when these things overheat, right.

Last edited by bigdv519; 02-07-05 at 12:23 AM. Reason: spelling
Old 02-07-05 | 12:24 AM
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you mount it to the rear of the radiator, which is a puller setup
and the stock clutch fan and shroud is very hard to beat for cooling power, but does rob some power.
remember that your e-fan isnt free power, the alt uses more power when it needs more

you should try to find a fan that fits the height of the radiator core to use as much cooling power as possible.
people say that a fiero fan works great, shroud fits the rad very nicely, but its a junkyard sorta thing.
Old 02-07-05 | 12:51 AM
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i'd like to see those results bigdv519
Old 02-07-05 | 01:10 AM
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FWIW I've been using the Perma-cool "finger chopper" for a couple years with good results. I think it is rated at 2850cfm. Also a note to the extra current draw on the alt. A properly wired E-fan won't run all the time, only at low speeds or when stopped etc. When on the highway or traveling at speeds above 35 or 40mph there should be enough airflow to cool the car and the E-fan won't be running. (though at low speeds there will be increased current draw).
Old 02-07-05 | 07:06 AM
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Originally Posted by lastphaseofthis
i have a new 9 inch 1500 cfm laying around, and i was wondering if taking the stock engine fan off and replacing it with this would free up some hp/making reving quicker...
I think you should read this first.

http://www.aaroncake.net/RX-7/efanmyth.htm

Originally Posted by bigdv519
I will soon enough post 3 different dyno results. One with stock fan. Second without fan, no electric fan. Third, with electric fan on (supposed electrical load on alternator). I'm dying to find out how much electrical load is on the alternator and how much hp the stock fan does take away. Just so people know, the run with out any fan will have a couple of air blowers in front of the car to have less factors (water temp) change from run to run.
This won't work. If you have other fans blowing air at the radiator, then the stock fan will do exactly what it's supposed to do when there is sufficient frontal airflow: nothing. It will basically be freewheeling.

There is no way you can test a thermoclutch fan on a dyno. It responds to changes in temperature, and that's the one thing that changes the most on a dyno. Your results will have no consistancy, because you cannot when and how much the clutch is engaged.
Old 02-07-05 | 09:10 AM
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ok, stock fan it is, but is there an aftermarket motor driven fan that would give more flow? just for the sake of being cool?, thanks for all your comments guys
Old 02-07-05 | 10:34 AM
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Originally Posted by lastphaseofthis
ok, stock fan it is, but is there an aftermarket motor driven fan that would give more flow? just for the sake of being cool?, thanks for all your comments guys
The thermostat regulates the tempertaure of the engine, not the fan.
Old 02-07-05 | 11:06 AM
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so there really is no purpose for changing to an e-fan, atlease not for a 7. ok topic closed.
Old 02-07-05 | 03:26 PM
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yes, there is a purpose. If you get a fan with enough flow, it is an improvement over the stock fan. for one thing, the stock shroud looks like **** and takes up all kinds of room. also, the clutch on the stock fan isnt that great...ie it spins a lot when it shouldnt. An electric fan only spins when it needs to, freeing up a bit of power the rest of the time. also, an electric fan is adjustable, so you can change the temp at which it comes on.

pat
Old 02-08-05 | 04:33 AM
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Originally Posted by patman
If you get a fan with enough flow, it is an improvement over the stock fan.
The radiator fan has one job to do, and the stock fan does it perfectly. An electric fan cannot do this job any better, so from a performance and functionality point of view, there is no improvement.

...the stock shroud looks like ****...
And how it looks is way more important than how it works...

...and takes up all kinds of room.
Yes it does occupy a lot of space, but it's interesting that despite how often this is listed as a benefit, very few people who remove the shroud actually put something in it's place. If you have nothing to put there, then it wasn't in the way was it?

...the clutch on the stock fan isnt that great...ie it spins a lot when it shouldnt. An electric fan only spins when it needs to, freeing up a bit of power the rest of the time.
Jeez, how many times does this need to be explained? When the fan is not required, the thermoclutch is almost completely disengaged and any engine power used is negligible. Both thermoclutch and electric fans are only using engine power when they are actually needed. The power gain from swapping is a myth perpetuated by the aftermarket.

...an electric fan is adjustable, so you can change the temp at which it comes on.
Electric fans are not adjustable. Adjustable temp switches are. This is not an advantage though because the operation of the thermoclutch works exactly the way it's supposed to, so no adjustment is necessary.

If you want an electric fan on your car that's fine. If it's done right (and that's a big if) it will work just as well. Just don't spread BS about the so-called advantages.
Old 02-08-05 | 04:36 AM
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The only reason I switched to an electric fan was because I was getting ridiculous belt slip on a serpentine belt setup.
Old 02-08-05 | 04:37 AM
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9" is too small, get a 16". It's just right for the height of the radiator. Works great, my car never overheated.
Old 02-08-05 | 04:39 AM
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I am sticking with the stock fan/shroud on my TII. I just got the Koyo and its main selling point for me was I could use the stock shroud.

Just my two cents.

James
Old 02-08-05 | 04:57 AM
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Originally Posted by snub disphenoid
The only reason I switched to an electric fan was because I was getting ridiculous belt slip on a serpentine belt setup.
Running two belts over the water pump (via a dual-belt alternator pulley) completely solved this problem for me.
Old 02-08-05 | 04:58 AM
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id rather do the dual pulley set up and keep my stock fan. I dont have that much hp on my t2
Old 02-08-05 | 05:25 AM
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Originally Posted by NZConvertible
Running two belts over the water pump (via a dual-belt alternator pulley) completely solved this problem for me.
I think if Camden had packaged a 6 or 7-rib pulley that was of the correct length, belt slip wouldn't have even been an issue for me.
Old 02-08-05 | 07:55 AM
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NZ, i want you to do something for me. I know you have a stock fan laying around somewhere. go pick it up, and at room temperature, spin the clutch. It spins, but not easily. in other words, whatver force it takes you to spin that fan, is the smallest force it ever puts on the engine. Not so an e-fan. when it is off, its completely off, no power used at all. Not to mention absence of load on the water pump, which do tend to fail fairly often in 7s.

Also I never said looks were more important, but that doesnt make it a non-issue. If I have an e-fan that works as well, or marginally better than the stocker, and it takes up way less room and looks way better, how is that a bad thing? I mean sure, it would be retarded if it didnt work as well, but mine works great.

Anyway, I realize that nothing will ever convince you on this, so maybe we should agree to disagree. The thing is, it isnt very cool when you go around saying other people are spewing BS, unless they really are. IF you wanna disagree, thats fine, but if youre gonna start making editorials, you better be damn sure youre right.

pat
Old 02-08-05 | 08:19 AM
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Originally Posted by lastphaseofthis
so there really is no purpose for changing to an e-fan, atlease not for a 7. ok topic closed.
Alternator usage is ~75amps/hp in the ~90% efficiency area.

Say the efan pulls 20amps when turned on (about 250 watts)

Even if the stock fan kills half a horse power from the driveline, the eletric fan would still be pulling less hp from the alternator. Not to mention, an efan wired correctly would only pull when needed.

Both methods are superior in their own ways. If you're looking for absolute power gain, the efan will come out ahead, but only by about 1/4-1hp dependant on the situation.

Personaly though, I feel the gain of not having the clutch fan in my engine bay is nice. That and my clutch fan was locked up and causing the belts to get eaten. On the other hand, the locked fan was probably keeping coolant cavitation down, considering the water pump pulley would just slip at high revs.
Old 02-08-05 | 10:42 AM
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This is ridiculous. The same misinformation posted again and again. This thread is done. If you want to read about electric fans, just do a search and read the 10,000 other threads out there which contain the same misinformation, and the same corrections (mostly from NZ and me).

Thread closed.
Old 02-08-05 | 12:20 PM
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Originally Posted by Aaron Cake
This is ridiculous. The same misinformation posted again and again. This thread is done. If you want to read about electric fans, just do a search and read the 10,000 other threads out there which contain the same misinformation, and the same corrections (mostly from NZ and me).

Thread closed.
I think we need to start closing these E fan threads as soon as they pop up, and come up with something in the FAQ for them.

The amount of bogus information that pops up in these threads is startling.
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