Intercooler fan controller

Johnny

Johnny

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Question: Just installed a air to air intercooler to my freshly built 2.5 DOH subaru motor, I installed 3 small puller spal fans and unfortunately my computer does not have a source to tell the fans to come on & off I could wire them with relays and install a dash on & off switch but would rather use a automatic fan switch. Do you guys know of a good quality controller that could handle the 3 fans ?. the fans pull about 5 amps each. I would prefer a probe type because I don't have a bung installed.

                                  Thanks in advance 

                          Johnny  

 
Wire through relays, one per fan and connect to ignition switch, let them run all the time the car is running. 

 
Thanks Rampage , I am considering that option . 

 
What about one of those old school electric fan controllers?  It should before than capable of driving a relay.  Heck you could probably drive all 3 fans if they only pull 5 amps. 

 
Thanks for the reply Babalos, I tried a flex-a-lite controller with only one relay and it would not hang on the relay. I assume there are some subaru guys running with  what  i am  trying to achieve , Just need to find the right controller . Worst case , I can wire in 3 relays and install a switch on the dash. When it's go time and the guys want to take off in a hurry, Knowing me I will forget to hit the switch. lol

                                 Thanks guys for the replies

                                         Johnny 

 
I’d just run it to the ignition. There is no time where the intercooler is too cold.

If you want it off when the starter is engaged, put two relays with the ignition going to 87a, the starter going to 86, the ground to 85, and 30 going to your second relay powering the fan. 

 
Rampage42 said:
Wire through relays, one per fan and connect to ignition switch, let them run all the time the car is running. 
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I did something close to this.  I connected them to run at the same time the fuel pump runs.  So they spin up when the ignition is first turned on but stop a few seconds after until the engine is fired up and running.  That way they don't run when i shut the car off and want to the radiator fans to keep running till the car cools off.

 
Which computer are you using?  For those building cars Holley efi lets you adjust all the perimeters of when they operate.

If you want a cheap and easy way to manage this use a timed relay.  

https://www.amazon.com/Time-Delay-Relay-seconds-SPDT/dp/B0744HSF8P/ref=sr_1_4?dchild=1&keywords=sealed+timer+relay&qid=1630350025&sr=8-4

Simply stated you wire it to your ignition switch that would then start a countdown of 10 seconds.  This allows you to keep the fans from coming on hurting your cranking power.

 
Thanks guys, I am going to hook them up just like LtPyro did. The computer I am running is the Microtech, Not to many people are familiar  with them. 

                                        Johnny

 
fuel pump trigger is what we do, that way you can also hear them run before you start the motor

they must be via a relay.  funny but i have seen some connected directly to the ign switch and when the ign switch is turned off the engine runs for 2 extra seconds--this is the fan (radiator or intercooler fans) becoming a generator keeping the ignition lit.  the 1psi hobb switch is not a good idea, why because your intercooler could still be hot from a previous pull and never get cooled down.  like said above you could never have the intercooler too cold

On my own car i do run them off an air temp switch but its set so low that once they are on they are probably on the rest of the trip (on@38c) why would i do that? because the two fans i have are quite loud and when starting my car on first time in the day or on a cold night they can be off for a bit

 
That's how I ended doing it , Off the fuel pump switch, Seems to work great but the fans are a bit annoying running all the time, I need to take some temp reading and perhaps I can down size the fans. 

           Johnny

 
Johnny said:
That's how I ended doing it , Off the fuel pump switch, Seems to work great but the fans are a bit annoying running all the time, I need to take some temp reading and perhaps I can down size the fans. 

           Johnny
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You can hear them over the engine running???

 
Johnny said:
I can't hear my motor with these fans, Perhaps I chose to big of fans, I may have to down size. 
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LOL, What size fans did you get?  I got dual 8" fans on mine.  The intercooler is approx 30"x9"x3".

 
Johnny said:
I can't hear my motor with these fans, Perhaps I chose to big of fans, I may have to down size. 
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Unpossible.  That's the sound of reliability right there.  :biggrin:

 
I installed 3 4inch fans, I haven't had any time to run some temp test's . I guess if I have my headset on it would be ok. I drive this car on the street and without headphones it is loud.

    Johnny

 
You might do something similar to what John has, but step it up to run somewhere above 120*f.  This shouldn't affect normal driving, your intake temps are above this anyway. When you start it (unless you live in PHX), and as long as you are casually driving it on the street, you will hardly hear them.

When driving (and logging this time of year) my daily, the IAT is 130+ a lot, like almost always.

 
Kraut_n_Rice said:
You might do something similar to what John has, but step it up to run somewhere above 120*f.  This shouldn't affect normal driving, your intake temps are above this anyway. When you start it (unless you live in PHX), and as long as you are casually driving it on the street, you will hardly hear them.

When driving (and logging this time of year) my daily, the IAT is 130+ a lot, like almost always.
Click to expand...
6v low, 12v high?

 
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