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Old 10-29-2008, 07:05 AM   #31
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the heat you were speaking of Drift 101 generated from the pressure is created from a compression ratio these fans do not have any power by design once the preesure becomes just a little bit high they stop moving air because they dont have enough power to exceed theyr very small compression ratio so small its rated in static pressure not even psi

now a air compressor is designed more for high compression and low volume this is when the friction you speak of generates heat your intake side is atmospheric pressure while you output side is 100 plus psi like 7 atmospheres if I remember atmospheric pressure is like 14-15 psi I think therefore the heat is created trying to squeeze all that into a can

a whole nother subject of this I would be interested is do these fans under the body change the aerodynamics of the body
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Old 10-29-2008, 07:51 AM   #32
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I prefer sucking rather than blowing air on to ESC. Once I nav esc which always were shutting down dou to overheating. I mounted fan to blow, then it was fried in 5 min run shut down after 4 minutes, but sucking out the air got me almost 7 minutes of runtime. Blowing is better on one desired distant object.
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Old 10-29-2008, 08:48 PM   #33
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Quote:
Originally Posted by TraceRacing View Post
fans blow, extractors suck.

What you want is to remove the heat generated by the motor, so you blow on it.

You can test this by burning youself with a soldering iron (if you are that way inclined) and see if "naturally" you blow on it or suck the burn...
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Thats a good way to look at it!
Been there, done that. Soldering iron burns HURT LIKE F#@&!% HELL! I also got in a fist fight with a table saw. Different story tho.

She's gone from suck to blow!

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Old 10-30-2008, 01:41 AM   #34
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i never see that Blowing a battery while charging will increase d IR...got 1 stupid guy in my place said so....end up overheating and burst his own battery cos he din BLOW with Fan while charging....hahahaha
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Old 10-30-2008, 10:42 AM   #35
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Why do most companies want there fans to blow on to the heat sink whether it be on an esc or on the motor? Because when it is blowing on it this creates a higher pressure and with that becomes heat right? so with sucking just the fact of that it is creating low pressure it will help with cooling! What do you think?



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Old 10-30-2008, 03:00 PM   #36
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You want to maximize the air flow over the component to be cooled.From an enclosed area you can exhaust warm air and draw in cooler ambient air. This is how a computer case exhaust fan works. If you have an open area around the item being cooled you direct the flow by blowing.

And dont forget that you dont suck the air. You create a delta pressure and air tries to equalize the pressure by flowing into the other side.
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Old 11-01-2008, 10:19 AM   #37
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Just thought i would chime in tha subject.

Look at fans in cars, many have electric ones that reside behind the radiator. the reason for thrm sucking air rather than blowing is that the heat build up in the tight space can cause the fan just to spin and NOT blow any air though. but placing it where the heat is extracted into cooler air that the molecules are not pressing back as they are trying to get away from the radiator.

Thus the most efficient way of doing it pullingit away not pushing it on.
This actually supports what I said about two fans. Because on a cars radiator, yes the fans pull the air away from the radiator, BUT there is a natural fan blowing air onto the radiator. The car moving forces air into the radiator, then the fans in the back pull all of the warm air away, cycling air through it. There for not pulling, nor blowing, but cycling air is the most effiecient way. Use two fans!
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Old 11-01-2008, 11:32 AM   #38
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Take a peak at this http://www.coolcanfan.com
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Do you have pics of the Type-R fan?
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Old 11-01-2008, 01:00 PM   #39
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Has anyone tried a ducted fan (impeller) for cooling motor/esc? If weight isn't a problem it would really suck or blow hard
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Old 11-01-2008, 02:06 PM   #40
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Originally Posted by MOTHER FOCAR View Post
if i was good enough to have any fans, i wouldn't mind if they sucked or blew..
HAHA Exactly
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Old 11-01-2008, 02:10 PM   #41
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I would said, when we want to cool down a dedicated area of heat source, we use blow. And when we want to cool down a large area, we use suck.

And that's why are most of our fan on the charger and power supply are sucking, while the fan are used to cool down the whole area inside.

As for the computer example may not work here, while we are talking about a cooling system instead of a single fan. Usually, the fan at the front and side, the fan blow, and the fan on the top and at the rear, it suck air out from the computer case.

when I see "pressure create heat", it's true but seems our ESC fan won't create enough pressure to make a difference. But I think of a funny idea from this, blowing fan also creat "thrust" and most of our ESC fan are horizontal. will we create more down froce if we suck air from the heat sink? it create thrust to the top = more down force.

Just joking, It won't make a big difference.
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Old 11-01-2008, 02:16 PM   #42
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a whole nother subject of this I would be interested is do these fans under the body change the aerodynamics of the body
oops. freeze had point out that already
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Old 11-01-2008, 02:20 PM   #43
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Or maybe if we cut a hole in the back of the body and mount a fan there blowing to the outside of the car we can go faster! and mount one blowing off the top of the car to make it push down harder for more downforce like y'all said!
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Old 11-01-2008, 02:26 PM   #44
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Or maybe if we cut a hole in the back of the body and mount a fan there blowing to the outside of the car we can go faster!
ya, put couple fan at the rear and blowing outside and connect it with a 11.1v 100mAh lipo (i think 100mAh are enough for 5 minutes) and connect it to our 3rd channel. Remember to turn it off at the end of stright
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Old 11-01-2008, 02:28 PM   #45
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Hmm... I might have to go charge up my batteries and do some speed runs... I think I have an old body sitting around somewhere that I can hack at
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