Opinions on PWM fan controllers

[snappytravis]

Originally Posted by andrewb70

Yes, that is my fan. The shroud even has a place for the controller to sit in.

There are a lot of details in my build thread:

http://ls1tech.com/forums/conversion...es-videos.html

The controller has 5 wires. Positive and negative that go to the fan, the positive and negative from the vehicle power, and the PWM- signal wire.

For power going into the controller I have the negative coming directly from the battery and the positive also from the battery but going through a 40 amp circuit breaker connected through the 3 cavity metripack 480 connector.



The PWM- signal wire goes from the 558-400 sub harness that connects to the Holley main harness. That wire also goes into the 3 cavity metripack 480 connector. All power wires are 10 gauge, while the signal wire is only 20 gauge. The 558-400 harness comes with 20 feet for each lead so there is plenty to run just about anywhere. Few more pics...






Andrew

It seems that I talked to spal about my fans, and they said that the corvette fans are brushless. I can't remember for sure, It may have been that my fans wouldn't work with the pwm controller. I can't remember. I think that is a sweet setup for sure. If I do another project I may go that route. Good Job and thanks for sharing the info. I know on Lous Change build thread they installed the same controllers. I will have to find it and see what fans they ran. They used 2 corvette controllers on it.
Thanks again, I understand it a lot better now.

[andrewb70]

Originally Posted by snappytravis

It seems that I talked to spal about my fans, and they said that the corvette fans are brushless. I can't remember for sure, It may have been that my fans wouldn't work with the pwm controller. I can't remember. I think that is a sweet setup for sure. If I do another project I may go that route. Good Job and thanks for sharing the info. I know on Lous Change build thread they installed the same controllers. I will have to find it and see what fans they ran. They used 2 corvette controllers on it.
Thanks again, I understand it a lot better now.

I can't imagine that an 80 dollar fan is anything fancy. I really don't see a link between PWM control and whether a fan motor is brushless or not. The ECU send a duty cycle command to the C6 controller, based on that command, the controller adjusts output voltage to the fan. It's as simple as that.

I think using 2 controllers is overkill. What's the current draw of the 11" Spal fans? My guess is that it is under 15 amps each.

Andrew

[GregWeld]

Originally Posted by andrewb70

I can't imagine that an 80 dollar fan is anything fancy. I really don't see a link between PWM control and whether a fan motor is brushless or not. The ECU send a duty cycle command to the C6 controller, based on that command, the controller adjusts output voltage to the fan. It's as simple as that.

I think using 2 controllers is overkill. What's the current draw of the 11" Spal fans? My guess is that it is under 15 amps each.

Andrew

Big difference when you're using PWM.... from what I've read doing research.

[andrewb70]

Originally Posted by GregWeld

Big difference when you're using PWM.... from what I've read doing research.

Greg,

Are you referring to PWM in general or using a brushless fan or both?

I absolutely love my set-up. The fan kicks on slowly and gently and speeds up as needed. Most of the time you can't even hear it run.

Andrew

[Larry R]

Originally Posted by andrewb70

Greg,

Are you referring to PWM in general or using a brushless fan or both?

I absolutely love my set-up. The fan kicks on slowly and gently and speeds up as needed. Most of the time you can't even hear it run.

Andrew

How does one incorporate operating an air conditioning compressor in your set up? I have seen some ideas on the forum, but am still not sure how to do it.

Thanks, Larry

[andrewb70]

Originally Posted by Larry R

How does one incorporate operating an air conditioning compressor in your set up? I have seen some ideas on the forum, but am still not sure how to do it.

Thanks, Larry

Larry,

I don't have AC, so I can't help. Others have done this, so hopefully they will give you some input. The following is a guess:

The AC compressor is controlled by the VA computer and not by the engine ECU. The ECU monitors AC pressure and coolant temp and adjusts the fan speed accordingly.

Andrew

[Larry R]

Originally Posted by andrewb70

Larry,

I don't have AC, so I can't help. Others have done this, so hopefully they will give you some input. The following is a guess:

The AC compressor is controlled by the VA computer and not by the engine ECU. The ECU monitors AC pressure and coolant temp and adjusts the fan speed accordingly.

Andrew

I am not familiar with the VA computer. Can you give me some insight? Thanks, Larry

[andrewb70]

Originally Posted by Larry R

I am not familiar with the VA computer. Can you give me some insight? Thanks, Larry

I wish I could, but as I said before, I don't have A/C on my cars.

Andrew

[Larry R]

Originally Posted by andrewb70

I wish I could, but as I said before, I don't have A/C on my cars.

Andrew

I wasn't trying to be obtuse, I did read that you do not have A/C. But since you mentioned the compressor was controlled by the VA computer, I was hoping you had some knowledge of that.

I have been studying this and I can see how to incorporate the PWM with the fans and my Holley HP, but not the A/C. One way I came up with to speed up the fans when the A/C comes on, is to use have the signal from the trinary switch go to a relay to shift the power to the fans from the PWM to a constant 12 volts for the duration of the higher pressure seen by the trinary switch. I would rather have it all go through the PWM but I don't believe I have enough I/O's with my HP to do this. Again, thanks for your input. Larry

[andrewb70]

Originally Posted by Larry R

I wasn't trying to be obtuse, I did read that you do not have A/C. But since you mentioned the compressor was controlled by the VA computer, I was hoping you had some knowledge of that.

I have been studying this and I can see how to incorporate the PWM with the fans and my Holley HP, but not the A/C. One way I came up with to speed up the fans when the A/C comes on, is to use have the signal from the trinary switch go to a relay to shift the power to the fans from the PWM to a constant 12 volts for the duration of the higher pressure seen by the trinary switch. I would rather have it all go through the PWM but I don't believe I have enough I/O's with my HP to do this. Again, thanks for your input. Larry

Toward the end of my Cougar build thread, I discuss how to configure the Holley software to have two PWM tables one for AC on and one for AC off. This way you can have the fans come on when the compressor is on.

http://www.pro-touring.com/threads/1...res-and-videos)

Andrew