Gain power by converting to an e-fan?
#27
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I am against the e-fan draw HP mentality; and what I am trying to prove is that it doesn't draw any power (well maybe 0.25hp). Notice that I am not claiming that the efan gives more HP; just that itd not how some want to put it...
In the e-fan link in my sig, click on the link about the S4 Fan Estimation, that gives you good info about the clutch fan.
Actually 90A at 12V is only 1080 watts, or about 1.3HP.
Also, the clutch fan does not take anything over 5hp. It would take less then 2 most of the time but usually in the decimal range.
#31
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I dont have an overly modded car but like any other 7 it needs to be worked on regularly... Its nice to clear as much crap out of the way as possible... Plus it just looks nicer...
#32
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So in reality an efan might cost you what, 0.35hp? A couple of things come to mind, can't think of a single person that can notice the difference between 0.35hp. The second thing that comes to mind is, the loss of HP on an efan setup cancels out with the extra weight that the eshaft is carrying with the stock fan setup, and\or any drag that it might cause on the engine.
#34
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So in conclusion an e-fan amp draw is next to nothing or in the decimal range
So in reality an efan might cost you what, 0.35hp? A couple of things come to mind, can't think of a single person that can notice the difference between 0.35hp. The second thing that comes to mind is, the loss of HP on an efan setup cancels out with the extra weight that the eshaft is carrying with the stock fan setup, and\or any drag that it might cause on the engine.
Are there over drive pulleys one could install?
#35
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I have never seen any but im sure you could get some made. Doing this though could over spin the alternator or water pump, depending on what you "overdrive". Personally, I would like to overdrive the alternator slightly, havn't done the math to figure out how much I could go but at idle, it seems to spin to slow to charge much.
an Overdrive pulley would be smaller than the shaft pulley(?), but i'd imagine it would only need a few mm to a cm in difference to get the desired affect.
What i'm curious about though is why anyone would want HP at idle? since both the efan and clutch fan usually only spin at low speeds or at idle. There's rumors of better throttle response from an efan and most who have done the conversion agree. Besides that and space it makes no real difference in the amount of usable HP. As for my reasons for conversion the fan and shroud were broken and I'm also planning on doing a N/A->turbo conversion (so with that space I can run intercooler piping).
#36
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an Overdrive pulley would be smaller than the shaft pulley(?), but i'd imagine it would only need a few mm to a cm in difference to get the desired affect
What i'm curious about though is why anyone would want HP at idle? since both the efan and clutch fan usually only spin at low speeds or at idle. There's rumors of better throttle response from an efan and most who have done the conversion agree. Besides that and space it makes no real difference in the amount of usable HP. As for my reasons for conversion the fan and shroud were broken and I'm also planning on doing a N/A->turbo conversion (so with that space I can run intercooler piping).
I can't remember if switching to an e-fan increased my throttle responce or not while the fan was off or on. Its been about 5 years. I can see how it would, but I don't think its anything to jump up and down over either.
#37
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Its not getting HP at idle, its trying to free up and HP through the poewr band that the clutch fan is said to consume. As I state before, its usually in the decimal range but can take as much as 2+ hp.
I can't remember if switching to an e-fan increased my throttle responce or not while the fan was off or on. Its been about 5 years. I can see how it would, but I don't think its anything to jump up and down over either.
#38
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The conversation is past this, but I'll add these two sentences anyway:
Those don't tell the whole story, but they're interesting to keep in mind!
- The clutch fan taps the engine's mechanical power directly, while the electric fan converts to electrical power at the alternator, then back to mechanical power at the fan, and each conversion is less than 100% efficient.
- Reasonable electric fans have an upper-limit of airflow, while the stock fan has a much higher limit.
Those don't tell the whole story, but they're interesting to keep in mind!
#39
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I still think this is more in people's heads than anything else, because it makes such a difference visually. There's not that much "on the engine" that's blocked by the shroud. I've worked on pretty much every part of my engine at some time or another, and only needed to remove the shroud once to remove the water pump. I'm doing something in the engine bay often and if it actually got in my way on a regular basis I'd be much more interested in removing it. What regular tasks would actually be made easier?
Last edited by NZConvertible; 06-03-07 at 06:25 PM.
#40
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#41
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would you gain any throttle response by getting an e-fan?
the only reason i'd get an e-fan is cause i would like to install a reverse vented hood, which WOULD help reduce engine bay temps.
the only reason i'd get an e-fan is cause i would like to install a reverse vented hood, which WOULD help reduce engine bay temps.
#42
Harder to a certain point, right?
If i was to follow your theory, a stock FC with a 90amp sound system, e fan, AC & headlights on; will barely move...
I am not going to lie, since i don't know if thats true or not; however I know that has RPM increases, so do the alternators amp output.
Yes, as load to the engine increases.
If i was to follow your theory, a stock FC with a 90amp sound system, e fan, AC & headlights on; will barely move...
I am not going to lie, since i don't know if thats true or not; however I know that has RPM increases, so do the alternators amp output.
Yes, as load to the engine increases.
Listen, I work at Advance Auto and test a lot of alternators. When you put a load on an alternator, it puts an electrical resistance on the shaft, and makes it harder to spin. If this wasn't true - then an alternator would produce max output at idle or at WOT - which is also a known fact that it doesnt.
The alternator does not increase amps based on RPM solely.
Any Mechanic will verify what I have said to be true. I am a mechanic myself. Maybe you should research your stuff before you make ignorant claims...
-Chris
#43
B O R I C U A
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Listen, I work at Advance Auto and test a lot of alternators. When you put a load on an alternator, it puts an electrical resistance on the shaft, and makes it harder to spin. If this wasn't true - then an alternator would produce max output at idle or at WOT - which is also a known fact that it doesnt.
The alternator does not increase amps based on RPM solely.
Any Mechanic will verify what I have said to be true. I am a mechanic myself. Maybe you should research your stuff before you make ignorant claims...
-Chris
The alternator does not increase amps based on RPM solely.
Any Mechanic will verify what I have said to be true. I am a mechanic myself. Maybe you should research your stuff before you make ignorant claims...
-Chris
Ohhh lord, a mechanic working at AAP
How about kicking my 90 amp sound sytem at full blast while the car is at idle; will the alt put out its "100" amps?
Yeah, didn't think so
So in conclusion, an alt will not put its max amp output at idle, irrelevant of load...
Last edited by KNONFS; 06-04-07 at 09:22 AM.
#44
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There is something you can do with an EFan that you can't do with a clutch fan. Switch it OFF before a run on the drag strip. That and controlling the exact on and off temps, and having it kick on and run after the car is shut down too cool things off.
But I would gladly go back to the clutch fan any day if I could. On my current setup it would spin backwards.
But I would gladly go back to the clutch fan any day if I could. On my current setup it would spin backwards.
#45
Respecognize!
oh hey look! a battery! it can STORE and RELEASE electrical energy? no ****!
#47
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Under such conditions, where the alternator is not supplying sufficient amps for the electrical draw on the system, the battery "chips in" from it's stored energy. Two problems follow from this - one is, that cannot go on indefinitely, as the battery will eventually run flat and voltage/amps supplied to electrical system will drop below that needed to keep the car running - although in practical terms, that would take a lot of time idling - possibly hours, depending on how much the battery has to "make up". Secondly, if extra load on the electrical system from an e-fan, for example, causes the car to draw on the battery while idling or at low speeds, the alternator will work harder once engine speeds increase to recharge the battery again, meaning it is possible that the extra load of the e-fan effectively remains on the engine, via the alternator and battery, after the fan may no longer be running - effectively, a deferred load.
I just read Mr. Cake's writeup on "the efan myth" - he's pretty much nailed it - and he effectively deals with the reasons you might want to use an efan - its just that hp gain isn't one. You'd almost certainly gain more by switching your tranny and diff lubes to a quality synthetic.
#49
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still think this is more in people's heads than anything else, because it makes such a difference visually. There's not that much "on the engine" that's blocked by the shroud. I've worked on pretty much every part of my engine at some time or another, and only needed to remove the shroud once to remove the water pump. I'm doing something in the engine bay often and if it actually got in my way on a regular basis I'd be much more interested in removing it. What regular tasks would actually be made easier?
This is the reason why the electric fan is a SIDEWAYS Add-on and not an UPGRADE. I like the looks of a cleaner, less cluttered, engine bay and so do many people. You on the other hand must be an old timer
#50
Did I say that an alternator will put out max amps at idle? No.
Let's see what i said:
"The alternator does not increase amps based on RPM solely."
WOW! I said "solely". When I test an alternator while it is on a car, I rev the engine to 2000 rpms so that I can put a full load on it. Then I test it at idle and it puts maybe 50-65% of a load on it - the exact percentage I do not know.
By the way we are talking about batteries. A battery is part of the charging system - it is a capacitor and a power conditioner. If you say that a battery has nothing to do with it, then please please please go take an automotive class and stay away from car forums for 3 months.
Well isn't that something? Once again you should research stuff before you make claims, and please read posts carefully
Last edited by Aaron Cake; 06-05-07 at 09:10 AM. Reason: Remove insult