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Discussion Starter · #1 ·
Please see thread on New Electric fan below...how could I be not addressing another problem with cooling if the electric fan did worse than the clutch..It's possible i may have not gotten a really good fan but doesn't logic tell you that if the clutch fan was doing better than the electric,then the prblem must lie in the fan and not some where else,also how could I be sacrificing bhp by running the electric along with the clutch?I know if you remove the clutch fan you should see improvement,but the electric is a draw on the alternator,not the engine!!(by the way,when I ran the electric alone I saw no noticeable difference!!)You should really think about giving answer before just blurting out shoddy advice,it's just not right!!Besides,I'm perfectly happy how the cooling system is running now,my QUESTION was how to handle the noise in my stereo,and thanks for the answer on that!!!!!!!
 

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<b>RE: Cooling System</b>

Mike, last I checked the alternator was driven by the engine - unless you have a special one that we don't know about. So it follows that a load on the alternator will be a load on the engine. Its just that it is usually more efficient (LESS of a drag) to run an 'effective' electric than an engine driven.

FWIW, an electric fan to cool a z-car usually pulls about 20 - 23 amps, needs to be partially shrouded and cost around $140 - $180.


Rcr X
 

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Discussion Starter · #3 ·
Again,it looks like we may have some morons out there.I'm pretty sure that an increase in draw off the alternator is not going to increase the load on the engine.The alternator will continue to spin regardless what devices it has to power.The engine will not work harder to accomodate for a draw on the alternator.It will just have less power to distribute amongst various systems.Are you going to try to tell me that your big bass stereo and amps aren't taking away from your bhp but somehow my electric fan is??I beleive the main reason for an electric fan conversion is so you can increase horsepower!!!Now don't all you greasemonkeys try and jump in and tell this is bs.Laying it out--no alternator is designed to increase resistance against the belt turning it,thereby reducing bhp,however a clutch fan does create resistance against the engine which even you morons out there should realize--geez!!Now I am still trying to get a good answer to my original dilemma,not just looking for someone to tell me I'm wrong.Come on!!!!!!!!!!!!!
 

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Hey Mike, Relax!!!

There is a capacitor located by the alternator and other by the coil. These capacitor should take care of any noises caused by electrical componets. Check that they are ok. You may want use additional capacitor just for the fan motor as well.

As far as HP loses and gains due to use electric fan. This is what I have learned. I have had my car on dyno with and without clucth fan. 0.7 HP increase without the OEM fan. It is not exactly turbo effect. However, there is one significant benefit of using electric fan. Lower engine noise. It also should improve throttle response little bit, but just a LITTLE bit.

Good luck shooting down those pesky noises.

Jarmo
 

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<b>RE: Cooling System</b>

Mike, I am not sure of the reason for your animosity, but calling names is not going to get people on this forum to help you out. I'm afraid only one person here is proving themselves to be the moron.

BTW, you might want to revisit some of your physics books from high school.
You CANNOT creat energy out of nowhere. An increase in OUTPUT energy (electromotive force - d/c voltage) of the alternator HAS to be accompanied by an increase in INPUT energy (from the engine). You are changing states, but energy has to come from somewhere.

I'm sorry that you didn't find the answer to your post.
I, like others, only try to share our experience to help out.


Rcr X ... With a cool running electric fan'ed z-car...
 

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<b>Once Again</b>

It is not nice to call people names. I should say you are a moron for buying an electric fan from Autozone and expecting it to be sufficient as a stand alone fan. You need atleast 2400 CFM out of the fan to keep you engine cool. Your fan probably only flows 1600-1800 CFM, not enough. Plan to spend $175 on a 16" fan capable of flowing enough air. As far as the noise, any hi-end car stereo place can provide you with a noise suppressor to dampen out the whine from the fan. I like humor and fun, but don't get in the habit of criticizing people who are trying to help. Don't bite the hand that feeds you!
 

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Well....Shoddy Advice HUH????read and learn...

Well, Mike Hanson, I don't know how much exactly you do or do not know about cars, generator/alternators, cooling systems, and common courtesy, it seems as though you are lacking in all areas based on your posts and calling people morons and saying that they are blurting out shoddy advice. I think that is down right rude especially since you came here asking for advice. When I give advice, I know what I am talking about, or I don't give the advice. I think you answered your own question about the loss of horespower didn't you! The reason I stated that, is that if you have a mechanical fan that is costing you HP and then you have an electrical fan that is costing you HP you will actually be decreasing the overall performance since you will be creating a greater load on your engine when the electric fan and mechanical fan are on at the same time. This is particularly true if the rest of your cooling system is not working properly. Your logic would say that we could put on six electric fans and still have the same usable horsepower right?...Wrong! Yes, big ass stereo systems also cost you HP when you run them. However, electric motors draw more amps than about anything in you car(except the monster stereo systems). Are you trying to tell me that the same load is being put on the engine when it is drawing 3 amps vs when it is drawing 50 amps for example???? Think about it for a while. I am sure your are intelligent enough to figure it out. When the demand for amps is increased on the alternator, it will make it harder to rotate the alternator. Thus, since the alternator is hooked up to the engine it will be putting a load on it which will yield less overall hp for street performance. Oh yeah, not to mention you will get worse mileage. There is a point of diminishing returns when it comes to using extra fans for cooling. If your thermostat isn't opening properly, you may only be getting half the amount of water that is being circulated through the radiator. Thus your fans will have to work longer to cool the engine down. You also run into this problem if your radiator core is half plugged up. Get the picture. I can draw you one sometime if you still don't understand(for reals). And don't bust on people trying to help you out just because you don't know yourself. I always answer people's questions when they ask me, maybe you should try asking some questions to people that are more knowledgable than yourself. No hostility is intended by this post, I just think you could have tried a little harder to be more couteous and inquisitive rather than rude and having an omniscient attitude.
Later,
Tim-Been working on cars before I knew how to drive them-Deesen
71' 240ZT
 

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go tim go...

at least I admit when I put my foot in my mouth. let's look at it this way: an electric fan draws 20A. (?)
take 20A multiplied by line voltage (13.8v) and you get 240watts (.024 kw). If I remember right it's like .6kw per HP? so the electric fan uses HP, albiet indirectly, from the engine. It indeed increases the resistance on the motor the more load it has. Let's not be so vicious! Sometimes we all have a brain fart, and should be open to another perspective on our problems. This is why we all come here, right?
 

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<b>Uh, a loaded alternator DOES drag more --></

I don't know where you studied physics but the energy comes from somewhere. The alternator puts more and more load on the engine as you put more electrical load on the system. Common sense (not so common?)
 

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Perpetual Energy

Once upon a time, on a little Z forum, Physicist Mike Hanson discovered the key to perpetual energy. Just attach many many alternators to in-line 6 Japanese internal combustion engines! After all, these alternator's loads don't increase as their output's rise! Why we can power entire cities this way! Okay, it's not quite perpetual energy - we will have to keep fuel running to the engines - but not much! After all, these alternators just require enough force to keep them spinning. That's all!
 

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RE: Well....Shoddy Advice HUH????read and learn...

Mike...
Look at it this way...a alt. is just the opsite of a electric motor, lets say a fan motor...the more power you give the motor the harder it would be for you to try to hold the shaft still. Even more power added and soon you would not be able to hold it at all. Well a alt. is just the reverse instead of receiving power it generates power,the more load you put on it the harder it has to work thus causing a greater magnetic pull inside..making it harder to turn over.

Just another way to look at it.

Later
Lloyd "ewan" Tillman
 

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I'm impressed!!!

I read some of these posts, and must say that I am most impressed with the general knowledge this forum seems to have. Definitely not a bunch of uneducated greasemonkeys in here.

As far as the alternator is concerned, you are all correct. As you increase the load (current draw) from the alternator, the rate of magnetic flux increases, which increases the amount of input force (rotational via engine belt) required to put out the correct voltage due to the higher current draw. You need more force to overcome the higher magnetic field. So, energy is not necessarily free, the world is still searching for a way to do that.

Another thing to consider. The more accessories you install on your car, the sooner you will start to reach the maximum amperage output of the alternator. When this happens, the voltage is decreased to accomodate the higher amperage draw (I=V/R). This decreases the amount of voltage/amps available to the coil which in turn reduces the effectiveness of your spark.
 

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I'm NOT impressed!!!

First most aftermarket fans (i.e. the AutoZone ones) do not draw twenty + amps they draw closer to ten and even less once spinning. Fans between 2000 and 2400 cfm will cool fine except in very extreme conditions (ask Motorsports). Everyone who is arguing about the performance loss from negligable rotor/stator resistance has forgotten about the battery and it's load buffering effect. You typically don't connect the fan (or any other load) DIRECTLY to the alternator. The output of the alternator must be regulated (hence your voltage regulator) because it's output varies with the speed of the engine (seems everyone forgot about that!). I am glad to see some of you know ohms law but it has no bearing (no pun intended) in the supposed loss of h.p. from an alternator. If you doubt the lack of direct alternator/fan relationship - disconnect your alternator belt and see if your fan still blows. Unless you have a weak battery this whole argument about alternator resistance is a moot point.
 

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RE: I'm NOT impressed!!!

It is true, that the battery is acting as a 'buffer' in the system. What should really be of concern here is the total amperage draw on the entire system. If the alternator is rated @60amps, you can quickly exceed the maximum amperage of the alternator. Especially if you start adding on multiple fans, high power ignition, install a high power stereo system or fancy lighting. Two things happen when you reach the maximum amperage of the alternator. First, things start to get hot, and can melt or burn, which is definitely a bad thing in more ways than one. Secondly, all of your accessories will begin to operate at less than optimum conditions, which can lead to further failures or loss of performance.

The performance loss associated with a higher amperage draw is somewhat of a moot point as Roger said, but is a correct one none the less. Of course we are only talking about less than 1bhp, but that is still power. Best thing to do is stay within the rated amps for that alternator, or upgrade to a higher output alternator if you need all those accessories. When selecting an alternator, you need to factor in all electrical devices at one time. This means you need to add up the amperage draw from the headlights, wipers, stereo, engine, fans, etc.... to select the appropriate alternator, as it is possible for all of these to be on at the same time, and you want to stay below that total amperage threshold to ensure that all electrical devices will work properly at ALL times.

BTW, I'm still impressed with the general knowledge of this forum, even if we do get way off topic like we are now. ;-)
 
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