Gain power by converting to an e-fan?
#101
Engine, Not Motor
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Interesting. Thanks.
Now going back to the part where the engine power consumption will be the same to move the same amount of air. Wouldn't this also depend on the blade type and angle of the blades as well? I can't see the electric fan consuming over 2hp to move 2500 CFM of air like the clutch fan does at peak efficency. Most fans moving this amount of air consume about 15 amps. Even doing the math for 50% efficiency it doesn't add up to 1hp. Yes I know 1 hp is not even measureable really and nothing to worry about, but to say the consume the same amount of power to move the same amount of air, I think is incorrect.
Just my opinion.
Now going back to the part where the engine power consumption will be the same to move the same amount of air. Wouldn't this also depend on the blade type and angle of the blades as well? I can't see the electric fan consuming over 2hp to move 2500 CFM of air like the clutch fan does at peak efficency. Most fans moving this amount of air consume about 15 amps. Even doing the math for 50% efficiency it doesn't add up to 1hp. Yes I know 1 hp is not even measureable really and nothing to worry about, but to say the consume the same amount of power to move the same amount of air, I think is incorrect.
Just my opinion.
Honestly though, does it really matter how many CFM the fan flows? Who cares, as long as it works....
#102
B O R I C U A
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So when you say "cheap amps", you mean those by Alpine, Sony, Rockford Fosgate, Infinity, Kenwood, Clarion, JBL and probably many others who all rate their amps using the CEA-2006 standard, which requires power to be measured with an input voltage of 14.4V.
Even if your old amps are rated at 12V, 900W / 12V = 75A, so you're still wrong. Again.
Even if your old amps are rated at 12V, 900W / 12V = 75A, so you're still wrong. Again.
Damn bro, you are one HARD headed dude...
It depends, MOST of those brands have their cheap units, and their high end units; at most the high end units will give you their ratings at differents voltages.
The cheap ones will rate their PEAK watts at 14.4volts!
ONLY a FOOL will buy an amp based on a 14.4 volts rate; and you sir seems to be one of them. You want some proof? Taken fromt one the product websites that YOU mentioned:
SPECIFICATIONS
CEA-2006 Power Rating
• CEA-2006 Power Rating (40hm@14.4V = 1%THD+N), S/N 80dBA (Ref. 1W into 4Ohm): 60W x 5
RMS Power (at 12V,20Hz-200Hz)
• Per Channel into 4Ohms (·1% THD+N) : 45W x 5
• Per channel into 4 ohms : 45W x 5
http://www.alpine-usa.com/US-en/prod...&lang=en&tab=F
So, back to you saying that I am wrong...
Back in the days we used to measure the watts output before clipping on our amps; the ones we used produce over 30% total watts over the rated number at 12V.
#104
B O R I C U A
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My, what an entertaining three pages this has been.
One thing I haven't seen mentioned yet is when e-fans are typically installed...and yes, this completely sidesteps the question/debate over relative efficiency but seems like a practical issue to raise.
I suspect that fans are rarely changed without also swapping in a new, and typically more efficient (i.e., higher capacity), radiator as well.
When I built up my 240Z the stock single row radiator got shitcanned in favor of a three row Nismo competition unit. At the same time a dual fan electric setup went in controlled by a thermoswitch from a Saab 9000 (they come stock with a adaptor that splices into the radiator hose and are easily and cheaply available in junkyards).
This setup was so efficient that the fans rarely kicked in- never in the winter and only after prolonged idling in the summer. When the car was shut down the fans would kick on for a few minutes and then stop.
The combination of e-fan and larger rad seemed more efficient since the constant (minimal) parasitic drag of the stock thermo clutch fan was eliminated and the electric fans were usually idle.
When I get around to replacing my stock original radiator I'll probably go for a similar setup as the Z although I expect the e-fan to work more often due to the elevated operating temps of the rotary engine compared to the lower revving straight six.
So basically it would seem more practical to discuss the relative merits of the fans if the upgraded radiator was included in the equation as well.
One thing I haven't seen mentioned yet is when e-fans are typically installed...and yes, this completely sidesteps the question/debate over relative efficiency but seems like a practical issue to raise.
I suspect that fans are rarely changed without also swapping in a new, and typically more efficient (i.e., higher capacity), radiator as well.
When I built up my 240Z the stock single row radiator got shitcanned in favor of a three row Nismo competition unit. At the same time a dual fan electric setup went in controlled by a thermoswitch from a Saab 9000 (they come stock with a adaptor that splices into the radiator hose and are easily and cheaply available in junkyards).
This setup was so efficient that the fans rarely kicked in- never in the winter and only after prolonged idling in the summer. When the car was shut down the fans would kick on for a few minutes and then stop.
The combination of e-fan and larger rad seemed more efficient since the constant (minimal) parasitic drag of the stock thermo clutch fan was eliminated and the electric fans were usually idle.
When I get around to replacing my stock original radiator I'll probably go for a similar setup as the Z although I expect the e-fan to work more often due to the elevated operating temps of the rotary engine compared to the lower revving straight six.
So basically it would seem more practical to discuss the relative merits of the fans if the upgraded radiator was included in the equation as well.
#105
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If you look at the GM fans, they even have a strange blade position with a few equally spaced blades, then a few that are spaced closer together. Presumably this makes the fan much more efficient but I don't know enough about fan design (as most people don't either) to comment.
#107
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Originally Posted by KNONFS
It depends, MOST of those brands have their cheap units, and their high end units; at most the high end units will give you their ratings at differents voltages.
ONLY a FOOL will buy an amp based on a 14.4 volts rate; and you sir seems to be one of them. You want some proof? Taken fromt one the product websites that YOU mentioned...
So, back to you saying that I am wrong...
Back in the days we used to measure the watts output before clipping on our amps; the ones we used produce over 30% total watts over the rated number at 12V.
Back in the days we used to measure the watts output before clipping on our amps; the ones we used produce over 30% total watts over the rated number at 12V.
It gets better, if you use a stand alone ECU; the ecu will turn on and off the efan as dictated by the program\map\user.
I agree, as long as it goes both ways
For some reason, I normally see a one side argument; but not the other.
For some reason, I normally see a one side argument; but not the other.
Last edited by NZConvertible; 06-08-07 at 09:17 AM.
#108
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You realize CEA-2006 started a year ago, right?
BTW - I do consider SONY a cheap car audio brand, among others that you mentioned.
Why would I care how much power it makes at 12V? The only reason for me to look at power ratings is to compare with other units, so a standard voltage is necessary. Only a fool would make comparisons at different voltages. My car spends most of its time closer to 14.4V than 12V anyway...
When you are blasting your 50amp sound sytem, AC, and running your headlights at night; I guarantee you that you are NOT seeing 14.4 volts; not even 13v!!
Show me where I said it could only be done by an EMS?
BTW - Don't really see how you make the engine run hotter than normal.
#109
Crash Auto?Fix Auto.
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And FWIW, I can run every electrical system on my FC (which includes two Mercury Mystique E-fans) aside from the rear defrost and still pull 13.5V to my re-located battery. On only an FD alt. I don't see what you're getting at here.
Any what does ANY of this have to do with E-fans/clutch fans? Let it go and let the thread progress or die man.
#111
B O R I C U A
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How does A/C draw more electric current? The blower fan?
And FWIW, I can run every electrical system on my FC (which includes two Mercury Mystique E-fans) aside from the rear defrost and still pull 13.5V to my re-located battery. On only an FD alt. I don't see what you're getting at here.
Any what does ANY of this have to do with E-fans/clutch fans? Let it go and let the thread progress or die man.
And FWIW, I can run every electrical system on my FC (which includes two Mercury Mystique E-fans) aside from the rear defrost and still pull 13.5V to my re-located battery. On only an FD alt. I don't see what you're getting at here.
Any what does ANY of this have to do with E-fans/clutch fans? Let it go and let the thread progress or die man.
Do you have an aftermarket sound sytem? Have you measured the voltage when your sound sytem is at mid-high volume?
And please don't tell me you are running a 20 amp sound system.
On any case, its about the amps demand on the FC electrical system; it doesn't matter if its from an efan or from a sound system.
#112
Engine, Not Motor
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Enough with the off topic posts. If people want to argue stereo/amp wattage ratings, there is an Interior/Exterior/Audio forum on this site. This topic is for e-fans, and nothing else.
If the off topic posts continue I will begin deleting them and close the thread if necessary.
We have not had a real e-fan thread in a long time, which is why this thread has been left open but if it becomes too much of a pain in the butt, I'll close it.
Thanks.
If the off topic posts continue I will begin deleting them and close the thread if necessary.
We have not had a real e-fan thread in a long time, which is why this thread has been left open but if it becomes too much of a pain in the butt, I'll close it.
Thanks.
#113
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You implied it even if you didn't mean to. Nobody was talking about EMS's, so what what was your point? Why even bring them up?
Being able to set the temp the fan runs is another advantage often claimed for e-fans, but you can't make the engine run any cooler than stock without taking out the thermostat, which is just dumb. So you can only make the engine run hotter (sometimes) by turning the fan on later. Where's the advantage in that?
Don't really see how you make the engine run hotter than normal.
#114
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Originally Posted by Aaron Cake
Honestly though, does it really matter how many CFM the fan flows? Who cares, as long as it works....
Really the main myth that I want to bust are the massive HP claims and whatnot.
Originally Posted by KNONFS
It gets better, if you use a stand alone ECU; the ecu will turn on and off the efan as dictated by the program\map\user.
I guarantee you that you are NOT seeing 14.4 volts; not even 13v!!
Originally Posted by clokker
When the car was shut down the fans would kick on for a few minutes and then stop.
They are on their own personal vendettas. I say let them duke it out, and we praise the victor.
Just kidding, threads turn into wars very easily unfortunatly. Everyone has their own opinions on stuff. One of the problems I see is people giving right advice, but others not seeing a use for whatever it is so they bitch about why this, and why that when they could have just left everything alone. O well. Its the net for ya
#115
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No, that's not what I said...
Maybe you need simpler terms. If fans, alternators and electric motors were 100% efficient, it would require X amount of work done by the engine to move the required amount of air, whether the fan was mechanical or electric. But fans, alternators and electric motors aren't 100% efficient, so it actually takes X+Y amount of work done by the engine to move the required amount of air, where Y is the engine power that overcomes all the combined inefficiencies of a particular set-up. My point is that Y for a typical electric fan is not different enough from Y for the stock fan to give a **** about. Simple as that.
I do agree thats its not enough to give a **** about. Up to around 1hp gain, if ANY. There are many benefits to the clutch fan as well as the e-fan. For one, water pump slipage due to the airpump being pulled off and the clutch fan being on the same pulley. I have seen to many times dual belt pulleys not helping in this area.
#116
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I know that an e-fan alleviates the needs for dual belts (been there, done that), but a pulley is a lot cheaper than a proper e-fan set-up.
#117
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Why bring it up? because that's how I have my efan configured.
Being able to set the temp the fan runs is another advantage often claimed for e-fans, but you can't make the engine run any cooler than stock without taking out the thermostat, which is just dumb. So you can only make the engine run hotter (sometimes) by turning the fan on later. Where's the advantage in that?
#119
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And that would be what?
I never said you did.
Oh jeez... I did not say that. Unless you're actually quoting someone, don't use quotation marks! That's basic grammar, not to mention that it's incredibly rude to deliberately make it look like someone said something they didn't. If you're going to continue this, quote me properly and stop making stuff up, or STFU.
What I said was"you can only make the engine run hotter (sometimes) by turning the fan on later". The "sometimes" refers to the fact that this will only happen at low speed when the fan is required.
Actually most people do set their e-fans to run the engine hotter than with the stock fan. I regularly see people say their fan's come on between 190 and 200degF, which is much hotter than the engine runs at low load with the stock fan.
But my point (which you seem to have missed) was that the ability to set what temp an e-fan turns on and off is not an advantage over the stock fan. How could it be?
I never said run cooler...
...and you did said "might make it run hotter"
What I said was"you can only make the engine run hotter (sometimes) by turning the fan on later". The "sometimes" refers to the fact that this will only happen at low speed when the fan is required.
unless the person wants to do that on purpose, I don't see it happening.
But my point (which you seem to have missed) was that the ability to set what temp an e-fan turns on and off is not an advantage over the stock fan. How could it be?
#120
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Many times? Because the sheer number of people who appear to be succussfully running that set-up would indicate it'll work fine if it's done right. If it really was a problem they're be lots of "dual belts didn't solve my slipping problem" threads, but there are virtually none. I've never had a belt slippage problem in the 3-4 years since fitting one. I would guess that in cases of this happening crappy belts or improper tensioning would be to blame.
I know that an e-fan alleviates the needs for dual belts (been there, done that), but a pulley is a lot cheaper than a proper e-fan set-up.
I know that an e-fan alleviates the needs for dual belts (been there, done that), but a pulley is a lot cheaper than a proper e-fan set-up.
There are a lot of rotary owners out there and lots of people that have tried dual belt pulley and have either had successful experience or not successful experience.
What I said was"you can only make the engine run hotter (sometimes) by turning the fan on later". The "sometimes" refers to the fact that this will only happen at low speed when the fan is required.
#121
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Saying that I was implying that the ONLY way of running temp control on an efan was by an EMS.
OK then, here is wat YOU wrote:
So if we go by what you said, should you STFU?!?!?
Oh jeez... I did not say that. Unless you're actually quoting someone, don't use quotation marks! That's basic grammar, not to mention that it's incredibly rude to deliberately make it look like someone said something they didn't. If you're going to continue this, quote me properly and stop making stuff up, or STFU.
What I said was"you can only make the engine run hotter (sometimes) by turning the fan on later". The "sometimes" refers to the fact that this will only happen at low speed when the fan is required.
What I said was"you can only make the engine run hotter (sometimes) by turning the fan on later". The "sometimes" refers to the fact that this will only happen at low speed when the fan is required.
So if we go by what you said, should you STFU?!?!?
#122
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I don't know what the CFM rating is on the GM fans that I use, but I do know the current draw. I'm also not worried at all about the CFM rating because the fan works either way.
#123
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I could be an *** and say, no you did not say that and it looks like a blanketed statement, but I wont.
I'm talking about all the fans really. I don't know the CFM rating of the stock fan and I suspect it's hard to test as you would need to spin it at the appropriate RPM ratings, in the shroud, with a rad in front of it and then somehow measure air flow (maybe a magnehelic meter to measure pressure drop at a venturi?).
If someone really did want to measure the stock fan's performance in-situ, the best way to do it would be with an air velocity meter. You'd need to take about 8-10 readings at even spacings across the radiator core and average them, then multiply by the core area. Getting a constant fan speed would be pretty tricky though. Maybe use a temporarily-mounted electric motor to drive it via a belt...
#124
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So you saw a few people post about their problems. Why would anyone post if they didn't have problems? I guarantee you the succeses will greatly outnumber the failures, and the failures were most likely improper installation. Why else would it work on most cars and not others? The pump/belts/fan set-up is practically identical on every FC.
Also, most of the time these are on high HP turboed cars where each engine has a different amount of HP. If the engine spins up to quick, the water pump could easily slip. Take a guess as to which side of the belt loosens up when you press the accelerator pedal and which side tightens up. Since there is a load on the alternator and that pulley is not free wheeling, the left side of the pulleys will be the side the belt loosen up on. The belt actually stretches which causes this. The amount the belt loosens can be an unseen amount but I have personally the belt get slightly looser then the other side. To you, I must not have the belt tight enough, or I installed the belts wrong.
#125
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So getting back to the e-fan Topic.
I was just thinking. Which is not always a good thing. As seen above
Putting a E-fan on a shroud would cause the fan to run at a higher efficiency then putting it straight on the rad due to the increase surface area it is able to pull air through, correct? Not saying the conversion from electrical to mechanical but the amount of current it would consume plus the amount of CFM it would pull, since having it directly on the rad decreases the surface area, or the amount of gaps it can pull air through, which would limit the CFM, since the CFM rating is measured also by the amount of total surface area the fan can pull from, otherwise it would be at zero static pressure, open air.
Am I going off the deep end here and thinking stupid?
I was just thinking. Which is not always a good thing. As seen above
Putting a E-fan on a shroud would cause the fan to run at a higher efficiency then putting it straight on the rad due to the increase surface area it is able to pull air through, correct? Not saying the conversion from electrical to mechanical but the amount of current it would consume plus the amount of CFM it would pull, since having it directly on the rad decreases the surface area, or the amount of gaps it can pull air through, which would limit the CFM, since the CFM rating is measured also by the amount of total surface area the fan can pull from, otherwise it would be at zero static pressure, open air.
Am I going off the deep end here and thinking stupid?