Cooling Fan Tech

[WaterH]

That's partly why I like those relays, they have secure screw terminals for the high power.
If your battery, wiring, and fuses are good for the load then it is a simpler system to turn everything on at the same time. Keep in mind I had a perfect storm one time where I had all the lights on, two fans on and I think the third fan and the air compressor turned on at the same exact time and it popped the main circuit breaker. It only happened one time, never again. Plan for everything to turn on at the same time with a spike load even though it might only happen 1% of the time. For instance my compressor runs at 45 amps continuous but restart spike can hit 230 amps for a second. Your fans might run at 30 amps continuous but they could spike 90 amps at startup.

Main cercuit breaker? I've not seen that on a vehicle. Are you saying you have a main like a house? I do have a big fuse on my electric golf cart. It's a "souped up", 500 amp, 48 volt cart. Not sure of the amp rating on that fuse. What would the amp ratting be on yours? Is this cercuit breaker protecting the main cables? In my case, Im useing 2 O cables. I think the battery terminal would melt before the cable is exceeded.

 

[Bebop]

I would not run a variable speed controller with a brushed fan. If you want variable speed then you need to make the jump to Spal brushless fans with the built in controllers and matching temp sensors.

Why is that ? Plenty of OEMs did it and still do it to my knowledge.

Also, depending on what ECU you have, there is not need for a temp sensor with the aftermarket SPAL brushless stuff, you can output a PWM signal from the ECU and send it directly into the fan.

 

[HYDRODYNAMIC]

Main cercuit breaker? I've not seen that on a vehicle. Are you saying you have a main like a house? I do have a big fuse on my electric golf cart. It's a "souped up", 500 amp, 48 volt cart. Not sure of the amp rating on that fuse. What would the amp ratting be on yours? Is this cercuit breaker protecting the main cables? In my case, Im useing 2 O cables. I think the battery terminal would melt before the cable is exceeded.

I think the old buggy had a 150 as the main between the battery and the main control box that then broke down to smaller circuit breakers or fuses.
The curve shows they can handle up to 600% the rating for a short time period. I did not feel like interpolating the graph with a running load plus a spike load. But the load was probably 75% then a spike was added that tripped it.
https://www.bluesea.com/products/7189/285-Series_Circuit_Breaker_-_Surface_Mount_150A

 

[HYDRODYNAMIC]

Why is that ? Plenty of OEMs did it and still do it to my knowledge.

Also, depending on what ECU you have, there is not need for a temp sensor with the aftermarket SPAL brushless stuff, you can output a PWM signal from the ECU and send it directly into the fan.

In an earlier post, possibly in this thread I talked about the different ways to control a brushless fan. Not all ECMs work with all brushless fans but some do and that can be an option if you have the tools and know how to put the correct parts together. Then you have to factor in total cost to determine if it is reasonable. Is it worth the time to learn how to program or buy the programs or learn what parts work with what.

PWM brushed fan controls can be good on an economy car because they save energy. If the controller fails, the computer will probably know if the motor is running hot and tell you or save the engine. The whole system is packaged in the same stock location and protected from unforeseen hazards. History will show that putting OEM or aftermarket PWM controllers into off road vehicles and subjecting them to abuse will cause failures resulting in overheated or burned up engines. A simple relay and temp switch or manual switch trades efficiency for reliability and safety. It is also more dummy proof for install and troubleshooting.
The Spal brushless variable speed fans and controllers have been designed plug and play with safeties built in and are protected with waterproof and dustproof construction. So the failure points drop. The engineers could have easily made the temp sensors variable with possibly a pot or micro switch for external adjustment, but instead they make sealed fixed temps sensors in different ranges to make them more reliable.

 

[Bebop]

Well, since you already know what history will teach us, I guess I'll stop right there.

For those who want to keep looking into ways to PWM your existing fans, lateralG has a very good thread on the matter. It's very possible to program a E38/40/76 ECU for PWM operation with HPTuners and use a $40 AC-Delco part to do the job.

I'm doing it with a Holley Terminator X and some classic brushed SPAL fans, and the "controllers" being a simple solid state relay, I don't foresee any failure in the future.

 

[HYDRODYNAMIC]

Well, since you already know what history will teach us, I guess I'll stop right there.

For those who want to keep looking into ways to PWM your existing fans, lateralG has a very good thread on the matter. It's very possible to program a E38/40/76 ECU for PWM operation with HPTuners and use a $40 AC-Delco part to do the job.

I'm doing it with a Holley Terminator X and some classic brushed SPAL fans, and the "controllers" being a simple solid state relay, I don't foresee any failure in the future.

You are an example of someone who has the parts, tools, programming, and resources to make it work. It is the simplistic wheelers and racers who got burned by variable speed systems in the past and have no interest in it again, they just want reliable, or they are old and do not want to learn new tricks. Even Spal discontinued their aftermarket PWM controller a long time ago. Their solution was the brushless fan with integrated controller and sensors. Now the major manufactures use them as OEM. So I should clarify my earlier statement about OEM PWM is pertaining to the older systems of the past.

I assume you are going to use the C6 fan controller with your brushed fan of somewhere around the stock output of 32 amps or 400W. I have not been able to find any info on if these controllers limit current to protect from a stalled fan due to debris or a blade to guard or core strike. Do they offer any protection?

 

[Bebop]

Ford Fusion controler (same stuff without the vette tax).
I have no idea if they have protections like you're mentioning, but neither do brushed fans that are wired with relays. The install is fused of course.

People who don't want to learn new tricks or would rather keep the "good old stuff" said the same thing about EFI, auto trans etc...

I'd love to run brushless fans but they currently don't fit in my chassis nor I can afford them. But I really wanted the quietness from the PWM vs hearing fans blaring at full tilt in a trail rig so this was my solution.

 

[WaterH]

I have not been able to find any info on if these controllers limit current to protect from a stalled fan due to debris or a blade to guard or core strike. Do they offer any protection?

This is probably a stupid question. (I'm asking for a friend, lol)

If a brushed fan is stalled, would that be the same as a dead short? Assuming the answer is yes, if you have two (22 amp continuous) fans, would you run a 50 amp fuse to supply both? Or do you need to run two seperate 25 amp fuses?

What I'm asking is, if one fan is stalled (or fried) will the other get hurt? I'm thinking no, but I'm a little out of my league here.

 

[WaterH]

For those who want to keep looking into ways to PWM your existing fans, lateralG has a very good thread on the matter.

Would you have a link?

 

[HYDRODYNAMIC]

This is probably a stupid question. (I'm asking for a friend, lol)

If a brushed fan is stalled, would that be the same as a dead short? Assuming the answer is yes, if you have two (22 amp continuous) fans, would you run a 50 amp fuse to supply both? Or do you need to run two seperate 25 amp fuses?

What I'm asking is, if one fan is stalled (or fried) will the other get hurt? I'm thinking no, but I'm a little out of my league here.

A stalled or dragging fan will be sending all the power to a few winding's for too long and overheat them until the winding wire burns up or the fuse or breaker opens up.
You want to fuse each fan individually. You can still use one relay and have two fuses after it per fan. You would want to protect the relay and wiring upstream with a fuse or breaker large enough for both fans or even larger if that was part of a bigger circuit. That is why I had the 150 amp circuit breaker protecting a number of items and then smaller fuses per item downstream.

You can find a number of links for C6 fan controllers. Many hot rod forums have write ups on them. They are made by Siemens VDO and look like a aluminum finned box with proprietary wiring plug.
You can find some other PWM fan controllers like the Ford Focus controller that use a USCAR standard plug which is the same pigtails that Spal uses and sells harness's for their brushless models. This can simplify the wiring and harness building portion.

Not that I suggest making this Frankenstein, but the Spal brushless temp sensor is a PWM generator sending the signal to control the fan controller which is built into the motor. If the PWM signal is similar it could drive the Ford Focus controller without having to tap into an ECM and program it. Creating a stand alone system.

https://www.amazon.com/Radiator-Cool...91812054244-20

https://www.amazon.com/Dorman-902-2...G28RX80KE09&psc=1&refRID=MWPEV7Z0DG28RX80KE09

 

[HYDRODYNAMIC]

Ford Fusion controler (same stuff without the vette tax).
I have no idea if they have protections like you're mentioning, but neither do brushed fans that are wired with relays. The install is fused of course.

People who don't want to learn new tricks or would rather keep the "good old stuff" said the same thing about EFI, auto trans etc...

I'd love to run brushless fans but they currently don't fit in my chassis nor I can afford them. But I really wanted the quietness from the PWM vs hearing fans blaring at full tilt in a trail rig so this was my solution.

The old Spal PWM controller had over current protection and worked with fans less than 30A. People could put larger fans on them or dual fans it would burn the controller up. If it was used with their fans they new what it could handle but with so many different install variations, this is probably why many failed and they discontinued it.
What I am getting at is Spal had safeties built in for a specific fan load. There is a good chance all the other OEM controllers have safeties built in for the specific fan they where intended to run.

 

[Bebop]

This is probably a stupid question. (I'm asking for a friend, lol)

If a brushed fan is stalled, would that be the same as a dead short? Assuming the answer is yes, if you have two (22 amp continuous) fans, would you run a 50 amp fuse to supply both? Or do you need to run two seperate 25 amp fuses?

1 fuse per element of course.
If you got 1 fuse that's twice the size for 2 elements you could send up to the value the value of this fuse into 1 single element.

That's why you got a fuse block and not 1 big fuse for the whole car.

 

[Bebop]

The old Spal PWM controller had over current protection and worked with fans less than 30A. People could put larger fans on them or dual fans it would burn the controller up. If it was used with their fans they new what it could handle but with so many different install variations, this is probably why many failed and they discontinued it.
What I am getting at is Spal had safeties built in for a specific fan load. There is a good chance all the other OEM controllers have safeties built in for the specific fan they where intended to run.

I think they discontinued it because it was an extra part, more complex to install and less universal than their new fan that has everything built in. What people do with JY parts when hacking their controllers probably doesn't bother SPAL one bit.

The fact that people were wiring more than a 30A load on more than 1 aftermarket controller just proves your point that people are dumb and can't read instructions I guess.

Their engineers are probably laughing at us reading this anyway. There is one SPAL guy that posted a few times on a forum and gave some good insight on their parts and design but he dropped out of the face of the earth quickly. I'm sure he got 17000 PMs asking the same question.

 

[HYDRODYNAMIC]

Everyone from Spal I ever talked to is super smart, except for the one that hangs out here, yes you know who you are lurking in the shadows, withholding valuable information. I don’t blame them for staying out of the mess. That’s their work and they probably don’t want to answer stupid questions or get caught up in an issue. They could hire a full time tech just to answer forum questions, but it would be tricky not to go outside of their product scope and be blamed for failed experiments.

 

[WaterH]

1 fuse per element of course.
If you got 1 fuse that's twice the size for 2 elements you could send up to the value the value of this fuse into 1 single element.

That's why you got a fuse block and not 1 big fuse for the whole car.

In the case of a fuse block, some things can be on and others off. So that's not really applicable. In the case of my AC condenser fans, they will both be on or off. So if both fans draw 44 amps and one fan suddenly has a stick stop it, wouldn't the draw go up over 50 pretty quick? (Blowing the fuse)

I guess one fan could fail in such a way that it draws nothing. Then the second fan could get 50 amps if a stick stops it. But now you have a coincidental failure. Even in that case, it's not exactly catastrophic. I fly helicopters that have two magnetos that both must fail to stop the motor. If I was worried about coincidental failure, AC cooling fans is not where I would start.

 

[Bebop]

Hmmmmm 😑

 

[CTD NUT]

I'm having a bit of trouble finding vendors for these new Spal brushless fans. Where are people purchasing them these days?

 

[HYDRODYNAMIC]

I'm having a bit of trouble finding vendors for these new Spal brushless fans. Where are people purchasing them these days?

Hydraulic Controls or any industrial hydraulics supplier should be able to get them.
Hot rod shops can really jack up the price, shop around.
Kartek has the sensors and harness’s and a few fans for decent prices.

 

[Bebop]

Sooooo, I am looking into some cooling tech and found this piece of info on a website that seems to be giving some good info on rads etc:

http://www.lockhartmachine.ca/fan_blade_clearance.html

Fans should not operate with blade tips that overlap the sides or the radiator or radiator tanks. Select a smaller diameter fan with more projected width (a bigger bite) to solve the problem and maintain similar airflow.

When building my shroud, I made a point to fit the biggest/baddest fans I could and they totally overlap the rad tanks. See pic:

I was inspired by the premade shrouds offered by plenty of manufacturers, like CBR, Griffin or RonDavis :

I'm planning a cooling upgrade and will have to build another shroud.
Should I mimic what I've done or go for smaller fans that do not overlap the tanks ?

Paging HYDRODYNAMIC for some knowledge dump

 

[DMANbluesfreak]

I'm not sure why they say that, but since there's no justification, I'm calling BS. Manufacturers use mechanical fans who's blades are much larger in diameter than the radiator is tall all the time. They just have a shroud to ensure the blades are actually doing something. I know you'll have turbulence issues if a blade passes over a tank or something and the fan is right up against the radiator, but I think that if you have the fans off the surface of the radiator an inch or more and have a shroud, you should be ok.

A bigger fan is typically going to achieve more CFM at a lower blade speed (quieter), so I think you made the right choice. Even if some of this CFM is lost because the blades overlap the tanks, I think you're ahead of using smaller fans. I just don't have any numbers to back up my statements, so I'm curious to see if someone does.

 

[Weasel]

Good question though, I would think the overall larger coverage would be more beneficial then worrying about the little overhang but I'm just guesstimating.

 

[Bebop]

My new cooling package could either twin 12" 500W (each) fans side by side that overlap the tanks a little or a single monster 19" 850W unit that doesn't overlap.

Both options will be Spal brushless units.

The single fan route is substantially cheaper but I like the redundancy of 2 fans.

 

[Weasel]

I think a single would be fine, most of the buggies around here have singles and failure rates are very low. With that one big and a good PWM controller that thing would probably mostly run on lower speed from what I understand on the brushless units.

 

[HYDRODYNAMIC]

If the radiator is squarish then one fan is reasonable. If the radiator is rectangular then two fans can be better. You want a fan that will reach from the top to the bottom of the core. The more of the core you cover the better. If the fans overlap the core then that area will not be flowing as much air and will lower the load on the fan. If you have a brushed fan then the fan will speed up and end up pulling more from the open core side. If the fan is brushed then the rpm is controlled and a dead spot will reduce the load on the fan saving power. The fan will still pull the same from the open core area.
You want as much power as possible. Two motors will usually give you more total power. If you can get a smaller diameter fan with the same CFM as a bigger diameter to reduce overlap then that is the way to go. If you have to drop CFM to make it not overlap then it might not be worth it.
The shroud can also make or break the air flow. If the shroud is deep and can move air out to the sides then overlap is not going to be as noticeable as if the blade is right on top of the tanks with no room for air to bend around and flow.

 

[HYDRODYNAMIC]

I think a single would be fine, most of the buggies around here have singles and failure rates are very low. With that one big and a good PWM controller that thing would probably mostly run on lower speed from what I understand on the brushless units.

Although two fans sounds redundant, if one dies then you have a big hole in the shroud that the other fan will pull air through. Both fans need to run together to get max cooling. For a low temp one fan on one off then it’s not a big deal of bypass is occurring. But both on is required for high temp cooling.

 

[HYDRODYNAMIC]

I think a single would be fine, most of the buggies around here have singles and failure rates are very low. With that one big and a good PWM controller that thing would probably mostly run on lower speed from what I understand on the brushless units.

Location and ambient temps have a big effect of radiator and fan needs. What works for rock bouncers and technical crawling with light weight buggies doesn’t work for continuous throttle KOH racing on a hot year. Radiator location also has big effect, catching air flow at speed vs a radiator down low with fan only air flow.

 

[Weasel]

This local rig has been raced since 2009. Raced in cold and blazing hot weather. Single brushed fan, don't recall it ever failing. Works even with the radiator and nearly the worst possible angle - as a reference.

​

 

[Bebop]

I'm about to make something very similar to that in order to fit the radiator in front of my buggy.
Also, bypass airshocks FTW !

 

[Weasel]

The biggest pain was bleeding air, I they put a custom bleeder in the very top edge. It was awhile ago, but most of the TC rigs have a similar setup with a similar sized radiator (usually mounted more upright though) and single fan.

He put ORI's on now, it was a bit roly-polly with the air shocks.

 

[Bebop]

Gotcha. Currently my 28x15 is mounted at about 30degrees. If I want to go 28x19 I'll have to give it some more rake. Maybe not as extreme as this but still. I'm also going from 2 1.25" tubes to 3 1" tubes. So the rad is thicker by about 0.5".

The only difference with the big TC setup is that I will not mount it downflow style and it will stay crossflow.