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Does anyone have the exact dimensions of the Camaro SS fan if it's cut down to the bare minimum? My radiator core is 18" high by 24" wide so I think it would be close. Even if it was overhanging the core by a tiny bit I think it should still be OK. Also how deep is the fan by itself?
Yes, that's the reason why I've added different variations, so folks can pick and choose parts that fit their cars. With the variety of modules in this thread, you could add an oil or transmission cooler as well. Or an extra input to tell it you're at the track and you want the temps even cooler.
Hi Carl (my bad sir),
I have been looking through this thread all morning and I am super excited to get this going on my ls swap S10. I want to use the mitsubishi fan module to control a set of fans. I already have an arduino, the resistors, and other misc things I'll need. However, I would like to run the 3-wire temp sensor for a 98 f-body camaro. One pin (lower) will be for the original-style gauge in the S10, and the other two would have went to a PCM. This swap is carbed so no PCM setup. The other two pins will be going to the MSD ignition control box for timing retard based on coolant temp. Anyhow, I would like to tie in the temperature inputs of the arduino to this sending unit. Here is a link to the exact sensor I am using. And here is a pin out of the sensor.
I am sort of familiar with coding (Matlab) so I can kind of get my way around. My question is, I am not sure what values I should put in the section of code for this sensor. I could not find a data sheet on it. Should I do a test of the sending unit while varying the temp, measuring the voltage and resistance?
I appreciate this thread and all of your help thus far.
Clint
Last edited by hotrodclint; 04-14-2021 at 01:18 PM.
Clint, measure the resistance at the temperature you want it to start cooling and at the temperature for maximum fan power. Then we can pop the results using those values into the code.
Okay that will make things easy. And we can just use excel to create a linear function for the values between start and max. I will get back to you once I have some data. Thanks again,
Hi Carl,
I finally got around to getting data for the resistance at various temps. I believe for this application I would like for the fans to turn on at 198 and turn off at 180. Let me know what else you think I may need.
Thank you,
Clint
Here is an excel sheet with the data:
The other two pins will be going to the MSD ignition control box for timing retard based on coolant temp.
So it sounds like instead of going to an ECM, your temp sensor goes to an MSD box. Most likely, the MSD box has a series resistor going to 5V just like the ECM would and the other sensor wire is likely going to ground. The way to find the value of the MSDs series resistor is to measure the voltage at any of the temperatures that are in your chart.
Lets do an example. Let's say you measure your voltage at the sensor while it's connected to the MSD box and it is 120 degrees. According to your table the sensors resistance is 1338 ohms at 120 degrees.
If you measured 2 volts then Rmsdbox = E / I = (5 - 2) / ( 2 / 1338) = 2007 ohms
If you measured 1.5 volts then Rmsdbox = E / I = (5 - 1.5) / ( 1.5 / 1338) = 3122 ohms
Make some voltage measurements and let's see what the resistance in the MSD is. Once we know what the MSD series resistance is, we can figure out the voltages at 180 degrees and 198 degrees and pop that into the code for starting up the fan and full power.
Here is a one-speed fan, soft start, no PCM, holly or arduino required, just 1 relay. Works for 1 or 2 fans.
If you can turn a relay on and off, you can do this.
The relay is the on/off. The controller softens the blow, electrically.
You wire the coil side of the relay anyway you need to.
Looking at this gave me an idea, and I edited the quoted post for clarity as it applies to my point. Click on it to see the original, of course.
My main objective in a fan controller is avoiding the sudden current load of a strictly-relay setup. It is mentioned that these controllers (either the Mazda/Mitsu or Corvette/Ford Contour) allow a soft start even at full jolt.
What if a single 75 amp relay fed the Contour controller with its sensor wire UNUSED, allowing a single speed, but more gradual ramping up to speed compared to relay alone?
Simple system, no shock load on the electrical system?? Just brainstorming here....
Looking at this gave me an idea, and I edited the quoted post for clarity as it applies to my point. Click on it to see the original, of course.
My main objective in a fan controller is avoiding the sudden current load of a strictly-relay setup. It is mentioned that these controllers (either the Mazda/Mitsu or Corvette/Ford Contour) allow a soft start even at full jolt.
What if a single 75 amp relay fed the Contour controller with its sensor wire UNUSED, allowing a single speed, but more gradual ramping up to speed compared to relay alone?
Simple system, no shock load on the electrical system?? Just brainstorming here....
The Corvette/Ford controller won't turn on without a pwm.
The Mazda/Mitsu will. I would make sure the fan is connected to the controller first before I turned the relay on or off. Test it and let us know how it works out.
Thank you! One question- How much current can the M/M unit handle? The GM truck fans I will be using soak up 25-30 (I think combined) on startup, settling to 18-25 once spinning.
I may need 2 modules, though being they have sockets for 2 fans, one module would wire up nicely.
Are there any other controller modules that will do as the M/M unit does? I see the Chrysler/Jeep unit (looks like a mini waffle iron) advertised a lot. How tough is it?
Thank you! One question- How much current can the M/M unit handle? The GM truck fans I will be using soak up 25-30 (I think combined) on startup, settling to 18-25 once spinning.
I may need 2 modules, though being they have sockets for 2 fans, one module would wire up nicely.
Are there any other controller modules that will do as the M/M unit does? I see the Chrysler/Jeep unit (looks like a mini waffle iron) advertised a lot. How tough is it?
I don't have data on the maximum current for any of the modules. I run two fans, off one module, but my fans don't draw much.
I just looked back, as I thought I remembered you cooking a Mazda module, and I found on post #26, that did happen. Or as you said, "beat it to a pulp". So I doubt it would live running dual GM truck fans.
I was at a local salvage yard to pick up a part for my wife's car and on a whim I asked if they had the fans for a Chevrolet Volt. Sure enough, they had one.
For $75 I got dual 300 watt 12" brushless SPAL fans in a 26.5 x 16.5" shroud. These use the same connectors as the C7 fan. I am going to do some testing with them with the Holley Dominator.
Andrew
That answers my above questions. It DOES help to look around..... lol
I was at the JY picking up an engine for my new project and happen to see this fan in a pile. Took it home for $10. I'm going to need more cooling in the Vette when I get my A/C going. The shroud is 24 x 17.5 and 4" deep, an exact fit for my rad. It's brushless and PWM controlled and has an internal PMW controller and a 3 phase brushless controller made by Bosch.
Wires that feed it are 8 gauge, so that's a great sign.
I don't have any info on what car it came out of except that it's a Volvo. I tested it to see how it's controlled. It's and animal.
Basically it has a heavy Ground and +12 wire that goes to the battery and a small PWM control wire. The pwm wire has an internal pullup to 12V so all you need to drive this is a PWM- style or ground signal PWM.
I tested it with a PWM generator.
It worked fine with a PWM frequency between 100 and 312 hz. Anything out of that range, it shut down. I would guess 128hz that is being used by other fans would be good.
Full power was at 7-10% duty and low speed was 90%. anywhere outside that range it shuts off, so 0% or 100% duty are off. Keep in mind that the duty may be reversed with a Holley PWM-, depending on how you look at duty cycle. In any case, anywhere in between those duties, the fan adjusted speed. It did not have steps like the Vette or the MItsu modules, just smooth transitions.
At full blast, this fan drew about 45 amps. This thing really throws air.
If you'll excuse my ignorance, what are the main differences between wiring/installing brushless/brush-type fans?
The brushless fan types offer superior power in a small package. They have complicated controllers that are usually built in, and convert the 12DC to 3 phase A/C. So most often, they are simpler to install because the power module is already built in, as is the case in this Volvo unit or the BMW unit discussed before. In both those cases, just a heavy duty power source and ground and a single low power control PWM signal to run them.
The brushless fan types offer superior power in a small package. They have complicated controllers that are usually built in, and convert the 12DC to 3 phase A/C. So most often, they are simpler to install because the power module is already built in, as is the case in this Volvo unit or the BMW unit discussed before. In both those cases, just a heavy duty power source and ground and a single low power control PWM signal to run them.
So your Arduino would still be needed to run it in a stand alone situation. Thank you for the info! This is all very interesting!
So your Arduino would still be needed to run it in a stand alone situation. Thank you for the info! This is all very interesting!
Yes, or an aftermarket ECM, but no power module needed, probably not even a relay. Just power (fused), ground and a PWM signal source.
If you just wanted a soft start, full power fan, then all you would need with the BMW or Volvo fan would be a PWM generator box turned on and off by a standard temperature sensing switch. Hell you you had one of those high low switches, you could even rig it for a two speed an with soft start.
04-08-2021, 10:16 PM
