Re: Mercedes fan upgrade
[Re: Andrewh]
#838192
10/25/10 12:15 PM
10/25/10 12:15 PM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
Senior Member of the Junior Dragster Club
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Senior Member of the Junior Dragster Club
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
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Most of the talk as of late has been around the HHR fans.
A lot of people seem to really like those ones.
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Re: Mercedes fan upgrade
[Re: WILD BILL]
#838194
10/25/10 05:34 PM
10/25/10 05:34 PM
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Joined: Jan 2003
Posts: 28,067 Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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The HHR fans take a bit of hacking for tighter engine compartments and don't fit the radiator well. The Mercedes C-class fan is a near perfect fit and flows MUCH more air. Read this thread.Mercedes fan on (damaged) 26" radiator: Mercedes fan (WRONG STYLE but same size) on aftermarket radiator: HHR fan on the same radiator: Be sure you get the correct style Mercedes fan! The early style is on top. It's commonly found in the aftermarket. You need the fan on the bottom without the heat sink.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: Mercedes fan upgrade
[Re: feets]
#838195
10/25/10 08:26 PM
10/25/10 08:26 PM
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Joined: Jan 2003
Posts: 11,994 Benton, IL.
DaveRS23
Special needs idiot
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Special needs idiot
Joined: Jan 2003
Posts: 11,994
Benton, IL.
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Spal and others have fan controllers that are pulse width modulated. They run a little over $100. Wouldn't that let the aftermarket fans live? I have one of the aftermarket fans and since I have already modded it to fit the radiator, I may as well try the Spal controller on it.
The fan and a controller will end up being about $350 or so. That's not too much for this fan IF it will live for me.
So, what do you think? Will it fly?
Master, again and still
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Re: Mercedes fan upgrade
[Re: gtx69]
#838199
10/26/10 12:57 AM
10/26/10 12:57 AM
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Joined: Oct 2007
Posts: 3,870 Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,870
Oregon
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I just looked at the instructions for this controller: http://www.speedwaymotors.com/Spal-Pulse-Width-Modulated-Fan-Controller,35700.html and I don't believe it will work with the mercedes fan. From the wiring diagram, all of the current for the fan goes through the controller. Apparently they're using a 30A mosfet, or something else to switch the current, leading to the 30A limit. Looking at the first fan thread, there are two heavy wires going into the fan, and another smaller trigger wire. The trigger wire is where the PWM to control the speed would go, while the other two wires carry the heavy current. (I'm SWAGing that this is true) In other words, ideally, the controller itself is not switching the current for the fan; it's just telling the fan to turn on and off really fast. If the signal is on for 50% of the time, the fan will run at (roughly) half speed. Same thing for 25% or 75% input on the trigger wire. I just looked at a few other controllers, and they all seem to work like the SPAL one above; just a relay to turn on/off the fan at different temperatures. If we can't find a controller that will do that, I could whip out a design that would probably cost $40-$50 that would do just what we need; a simple PWM output corresponding to the engine temperature.
If you ever find yourself in a fair fight, your tactics suck.
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Re: Mercedes fan upgrade
[Re: hooziewhatsit]
#838200
10/26/10 10:48 AM
10/26/10 10:48 AM
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Joined: Jan 2003
Posts: 28,067 Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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If you could come up with a controller, I could send you a fan to play with. That would be an awesome combination for our cars.
BTW... the heavy leads on the fan carry 39 amps when on. They flash up to 50 amps on start up. There is an easy start spin up. You can see it in the video I made of the fan.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: Mercedes fan upgrade
[Re: hooziewhatsit]
#838202
10/26/10 08:53 PM
10/26/10 08:53 PM
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Joined: Jan 2003
Posts: 11,994 Benton, IL.
DaveRS23
Special needs idiot
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Special needs idiot
Joined: Jan 2003
Posts: 11,994
Benton, IL.
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I would really like to go this way since the fan is such a monster and is already mounted on my radiator. Let me know if you are going to make some of these up, I would certainly take one.
Thanks for the help on this!
Master, again and still
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Re: Mercedes fan upgrade
[Re: DaveRS23]
#838203
10/26/10 09:40 PM
10/26/10 09:40 PM
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Joined: Nov 2004
Posts: 7,274 s.w.fl
bonefish
OP
master
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OP
master
Joined: Nov 2004
Posts: 7,274
s.w.fl
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Quote:
I would really like to go this way since the fan is such a monster and is already mounted on my radiator. Let me know if you are going to make some of these up, I would certainly take one.
Thanks for the help on this!
me too
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Re: Mercedes fan upgrade
[Re: bonefish]
#838204
10/26/10 10:23 PM
10/26/10 10:23 PM
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Joined: Oct 2003
Posts: 3,698 NE Oklahoma
Von
master
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master
Joined: Oct 2003
Posts: 3,698
NE Oklahoma
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Id be interested in a controller also.
72 RR, Pump gas 440, 452s, 3800 lbs, Corked, ET Radials,. 11.33@117.72.
Same car, bone stock 346s, 9.5 comp, baby solid. 12.24@110.
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Re: Mercedes fan upgrade
[Re: Von]
#838205
10/27/10 01:35 AM
10/27/10 01:35 AM
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Joined: Oct 2007
Posts: 3,870 Oregon
hooziewhatsit
master
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master
Joined: Oct 2007
Posts: 3,870
Oregon
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I guess there's enough interest to continue with the thought... After looking at it some more, I don't think I'll be able to do it the really cheap way I may have to throw a microcontroller at it It would cost a little more, but it would have much better control over turn on and full speed temperatures, and would open the door to switching the current of the fan itself (for an HHR type fan without a trigger wire , and no wimpy 30A limit either ). I think it would work best if we could install another temp sender that I can test and that I know the graph of voltage/resistance is, like this cheap one.-OR- I make a little box that puts out an adjustable duty cycle (up to ~90% on) whenever it's turned on. ie, you can change the speed of the fan, but it'd be running at that speed all the time. This would be the cheapest solution. (Should we keep this in this thread, or start another one?)
If you ever find yourself in a fair fight, your tactics suck.
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Re: Mercedes fan upgrade
[Re: hooziewhatsit]
#838207
10/27/10 11:53 AM
10/27/10 11:53 AM
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Joined: Jan 2003
Posts: 28,067 Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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If it would be easier and more cost effective you could build a two step controller that works off an inexpensive sending unit. Have the fan running around 60% at 180 degrees and step it up to 90% at 200 degrees.
My experience with these fans tells me that should be more than sufficient for our cars.
The new style Mercedes fan Andrewh and I use runs at 90% when running with a constant 12 volts on the trigger. If you could cycle the controller quickly enough to approximate that it should be fine with the less desirable fans. The factory runs them at those speeds. The failure seems to come from the constant voltage heating up the controller.
Shoot me a PM with your address and I'll send you the dismounted fan motor I have and a bracket to hold it. That way you can play with it and not worry about having a 27" spinning blade chopping fingers and creating a hurricane.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind. - Stu Harmon
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Re: Mercedes fan upgrade
[Re: hooziewhatsit]
#838209
10/27/10 09:51 PM
10/27/10 09:51 PM
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Joined: Jan 2003
Posts: 11,994 Benton, IL.
DaveRS23
Special needs idiot
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Special needs idiot
Joined: Jan 2003
Posts: 11,994
Benton, IL.
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I am flexible on how you go about it. But I would prefer to either have a low and a high speed that the controller triggers itself with adjustable temps or a variable speed controller. Or said another way, I would rather not have just one speed or have to manually control it. I hope you do this.
Master, again and still
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