Broken fan - What Now

[GTS Dean]

Or, he could try FB and get about 67 random comments over 2 days - only 4 of which are worth the time to consider. Those would tell you the same thing as you found here.

 

[Viper Specialty]

Or, he could try FB and get about 67 random comments over 2 days - only 4 of which are worth the time to consider. Those would tell you the same thing as you found here.

Aint that the truth. FB has made it impossible to find any useful information.

I still dont understand why its seemingly so easy to separate a customer from their money doing something they dont need, and then seemingly impossible to separate them from their money when it comes to properly fixing something.

Research first, purchase second... and dont take the advice of parts warehouses that have ZERO experience in installing and maintaining what they are actually selling and only benefit when they make a sale. In the same way, stop taking comments as gospel on FB and websites from end users who know nothing beyond what they were told by the same people.

To quote two unrelated topics that apply "Facts dont care about your feelings!" and "Consider the source".

When a vendor like me who designs, works on, and sells this stuff is telling you to STOP buying things, and STOP spending money.... it may be time to listen. These fan threads have been beaten to death and it STILL keeps happening.

 

[Fatman2006]

CFM is not CFM when comparing a 10 horsepower fan to a pair of 1/8 horsepower.

That said, if you are going to do it, the easiest method is the Gen4/5 fan shroud assembly. When you need to control it, let me know and we can reconfigure the PCM for relay control instead of hydraulic.

I still think you are making mountains out of mole hills. If you want the system fixed, just contact me.

You're the man, will do thank you.

For the Gen 4/5 conversion, what's the general concept behind the install? Does the fan assembly drop in and use the same plug as the current hydraulic sensor? Or do I need to wire in a new plug?

I saw the Gen 4 shroud uses slide in tabs on the bottom of the shroud, do I just drill those for the screws at my mounting points? And do the rest of the mounting points on the Gen 4 shroud line up to the Gen 3 holes?

It's my understanding the stock alternator puts out 130 amps, off hand do you know how many amps the Gen 4 fans draw?

I have a ROE tune using SCT, will that affect reconfiguring the PCM?

Why not just replace the current fan module? It seems like you're going to spend more time and money trying to retrofit a new system than to just replace the old one since it seems like you found the problem. Then it's just a straight drop in and maybe a couple hundred bucks if that and you're done. It's not like these things are failing left and right. If not the same exact fan module, they used the same general design in Jeeps and Mercedes of the time in the hundreds of thousands of vehicles of volume. I think you only see anyone talk about it here because it's an unfamiliar system to a lot of people, so when anyone has a problem they ask about it and that's kind of what this forum is all about.

I didn't know that about Jeeps and Mercedes.

Do you know where I can buy the stock lines?

 

[Fatman2006]

Aint that the truth. FB has made it impossible to find any useful information.

I still dont understand why its seemingly so easy to separate a customer from their money doing something they dont need, and then seemingly impossible to separate them from their money when it comes to properly fixing something.

Research first, purchase second... and dont take the advice of parts warehouses that have ZERO experience in installing and maintaining what they are actually selling and only benefit when they make a sale. In the same way, stop taking comments as gospel on FB and websites from end users who know nothing beyond what they were told by the same people.

To quote two unrelated topics that apply "Facts dont care about your feelings!" and "Consider the source".

When a vendor like me who designs, works on, and sells this stuff is telling you to STOP buying things, and STOP spending money.... it may be time to listen. These fan threads have been beaten to death and it STILL keeps happening.

I don't have FB lol.

I did research before buying the aftermarket lines, most of which came from experiences of people using those same lines. There's even guys in this thread that said they have them and have no issues. Nothing I found while doing research indicated I would have any issues.

Either way, I am where I am, no point in dwelling on what I should have done.

 

[Viper Specialty]

You're the man, will do thank you.

For the Gen 4/5 conversion, what's the general concept behind the install? Does the fan assembly drop in and use the same plug as the current hydraulic sensor? Or do I need to wire in a new plug?

Youre severely underestimating this. You need to build a relay bank, add all the wiring, fuses, and everything else. NONE of it is there. The G3 Viper was never designed for electric fans.

I saw the Gen 4 shroud uses slide in tabs on the bottom of the shroud, do I just drill those for the screws at my mounting points? And do the rest of the mounting points on the Gen 4 shroud line up to the Gen 3 holes?

The fitment of a G4 module should be no different. they share the same radiator.

It's my understanding the stock alternator puts out 130 amps, off hand do you know how many amps the Gen 4 fans draw?

I would estimate 40-50 amps when both a running easily. One of the reasons G4's have bigger alternators than G3.

I have a ROE tune using SCT, will that affect reconfiguring the PCM?

Yes, it will. You would need to run one of our files instead.

I didn't know that about Jeeps and Mercedes.

Do you know where I can buy the stock lines?

I am sure I could track a line set down.

Again, I implore you, STOP, and think about what you are doing. Do you really think a G4 fan assembly, building a wiring harness and fan control PDC, reprogramming your ECU, and installing it all is going to be anywhere near the same cost as fixing what you already have and putting it back together?

 

[Viper Specialty]

I don't have FB lol.

I did research before buying the aftermarket lines, most of which came from experiences of people using those same lines. There's even guys in this thread that said they have them and have no issues. Nothing I found while doing research indicated I would have any issues.

The vast majority of those threads that I see, I post in to explain how ridiculous everyone is being. I have literally spent more time than I care to remember trying to get people to stop overreacting to what they dont understand when it comes to the hydraulic fan assemblies and the hydraulic lines. I cant believe you never saw any of them.

One of the main issues is that people refuse to admit they screwed up and wasted money, then they try to justify that position by talking other people into jumping off the bridge with them. They never even attempt to understand the actual problem, before or after.

The OEM lines are literally ZERO problem, with the one exception of the oem upper fitting o-ring seeping over time when it wears. The line itself and the other fittings are virtually never a problem. However, due to the OEM supplier making a mistake in replacement fittings, the aftermarket being complete morons on the same fitting, and hack-job techs, the OEM line becomes a nightmare of repeat failures when you dont know what you are doing to replace that fitting. Its so simple its laughable, but everyone rushes to save a dollar by grabbing the easiest parts sold by clueless people, and then they blame the line when it has nothing to do with it.

So... rather than spend <150 bucks on a good fitting, they spend 300 bucks on lines that fail readily, pay even more to install them, make a fluid mess of their cars, and end up with contamination issues like you have. I literally cant wrap my head around it.

Sure, there are guys with lines and the cars are fine. They got clean lines with good crimps and have no system issues putting them over the pressure limit. But... there are plenty who aren't that lucky like yourself, and they don't pipe up nearly often enough.

 

[Fatman2006]

Youre severely underestimating this. You need to build a relay bank, add all the wiring, fuses, and everything else. NONE of it is there. The G3 Viper was never designed for electric fans.

Nope, I'm not underestimating it at all. That's exactly what I thought. The steps involved are why I wasn't considering the Gen 4/5 route. And you confirmed that's not the option I want.

That said, if you are going to do it, the easiest method is the Gen4/5 fan shroud assembly.

Apparently not .

The fitment of a G4 module should be no different. they share the same radiator.

The shroud mounting is definitely different, but it doesn't matter because I'm not going that route.

Again, I implore you, STOP, and think about what you are doing. Do you really think a G4 fan assembly, building a wiring harness and fan control PDC, reprogramming your ECU, and installing it all is going to be anywhere near the same cost as fixing what you already have and putting it back together?

No need to stop, I'm just in the research phase trying to flesh out the best options. Let's keep the knowledge flowing!

On the topic of cost I'll defer to you. I can have an electric fan in the car for about $700 on the high side. That includes: a fan that moves 2200 CFM, fan controller, aluminum fan shroud, placement of the additional coolant sensor feeding the controller and a single high pressure line.

Do you think I can fix the hydraulic fan for less than that? I would need new lines, fittings and a hydraulic fan unit.

 

[Ramtuff]

So, go electric, what line and fitting from the pump are you going to use to supply the power steering? Not getting easier is it………..

 

[Fatman2006]

So, go electric, what line and fitting from the pump are you going to use to supply the power steering? Not getting easier is it………..

It gets way easier when you go electric. I ran a high pressure line from the pump to the rack using AN fittings, it worked perfectly.

There is no pressure drop after the fan, so the rack gets the same pressure whether the fan is there or not.

Case in point, the racks are interchangeable between some generations, having a hydraulic fan or electric. Hydraulically speaking, I see no reason this shouldn't work, and others have done the same conversion.

However, I'm no hydraulic engineer and certainly not a certified mechanic. So if you know a reason it won't work please let me know.

I'm in the research phase so I'm trying to take on as much knowledge as possible.

 

[Steve M]

Or, he could try FB and get about 67 random comments over 2 days - only 4 of which are worth the time to consider. Those would tell you the same thing as you found here.

This sounds like the way to go to me, only the 4 worthwhile comments will be buried as replies to other comments.

 

[Viper Specialty]

Nope, I'm not underestimating it at all. That's exactly what I thought. The steps involved are why I wasn't considering the Gen 4/5 route. And you confirmed that's not the option I want.

Yes, you are, and you will find out before this is over I imagine.

Apparently not .

If you are considering half-assed options like external fan controllers that are unable to properly determine actual PCM demands, AC status, etc, then sure, there are easier "generic" methods of doing it incorrectly.

The shroud mounting is definitely different, but it doesn't matter because I'm not going that route.

How can the shroud mounting be different when the Gen3 and 4 share the same radiator, and the radiator shroud and condenser mount to that same radiator?

No need to stop, I'm just in the research phase trying to flesh out the best options. Let's keep the knowledge flowing!

On the topic of cost I'll defer to you. I can have an electric fan in the car for about $700 on the high side. That includes: a fan that moves 2200 CFM, fan controller, aluminum fan shroud, placement of the additional coolant sensor feeding the controller and a single high pressure line.

2200CFM? That's a fart in the wind. That hydraulic module is OVER TEN THOUSAND, and even a Gen4 module is substantially higher.

Do you think I can fix the hydraulic fan for less than that? I would need new lines, fittings and a hydraulic fan unit.

Under 700? Unlikely, but not too far off.

 

[Viper Specialty]

It gets way easier when you go electric. I ran a high pressure line from the pump to the rack using AN fittings, it worked perfectly.

And then, you realize you are underestimating things again, like the fact that the fan based hydraulic pump volume and pressure differ from the standard version, both of which will change the steering dynamic and fluid temperatures.

There is no pressure drop after the fan, so the rack gets the same pressure whether the fan is there or not.

Not entirely accurate. A proportioning valve limits the rack pressure and biases flow to the fan, unless there is a pressure drop in which case it biases to the rack to retain steering function.

Case in point, the racks are interchangeable between some generations, having a hydraulic fan or electric. Hydraulically speaking, I see no reason this shouldn't work, and others have done the same conversion.

Rack yes. Everything else, no. And you should ask all the Ram SRT guys who went with electric conversions how that all worked out for them.

However, I'm no hydraulic engineer and certainly not a certified mechanic. So if you know a reason it won't work please let me know.

I'm in the research phase so I'm trying to take on as much knowledge as possible.

You should probably start taking the advice of the engineers and people who do this for a living.

Can electric be done? Yes. Can it work well? Yes. Can it be integrated and have no actual downsides? Yes. Can it be done for anywhere near what you claim or what you can fix that hydraulic system for? NO.

Just the simple pair of Brushless fans you would need to even come close to properly cooling that car already eclipse your budget, before the fan controller, shroud, or any wiring harnesses. A single electric fan of any type will not be reliable in stopped traffic on hot days in a Viper application, hence why they are all large-motor duals from G4 onward, and even those barely do the job. The radiator opening real-estate and underhood fitment is the problem, and a literal worst-case scenario, which is why the Hydraulic system was used in the first place... but its expensive, so it got the axe in light of tech that improved. Before better fan motor tech and a good dual setup arrived in Gen-4, and the expensive Hydraulic system in Gen-3, everything they tried was a problem in Gen-1 & 2, with their common overheating and wiring meltdown issues.

"Just because something works, doesn't mean its right, without downsides, or functional issues"

I think I'll step off my soapbox now, as it seems you're gonna do what you're gonna do regardless. This isnt an iron V8 or a car with a huge radiator and opening that barely needs any airflow to cool. Its got more in common with stationary loaded heavy-equipment cooling issues than a typical car.

 

[Fatman2006]

And then, you realize you are underestimating things again, like the fact that the fan based hydraulic pump volume and pressure differ from the standard version, both of which will change the steering dynamic and fluid temperatures.


Not entirely accurate. A proportioning valve limits the rack pressure and biases flow to the fan, unless there is a pressure drop in which case it biases to the rack to retain steering function.


Rack yes. Everything else, no. And you should ask all the Ram SRT guys who went with electric conversions how that all worked out for them.


You should probably start taking the advice of the engineers and people who do this for a living.

Can electric be done? Yes. Can it work well? Yes. Can it be integrated and have no actual downsides? Yes. Can it be done for anywhere near what you claim or what you can fix that hydraulic system for? NO.

Just the simple pair of Brushless fans you would need to even come close to properly cooling that car already eclipse your budget, before the fan controller, shroud, or any wiring harnesses. A single electric fan of any type will not be reliable in stopped traffic on hot days in a Viper application, hence why they are all large-motor duals from G4 onward, and even those barely do the job. The radiator opening real-estate and underhood fitment is the problem, and a literal worst-case scenario, which is why the Hydraulic system was used in the first place... but its expensive, so it got the axe in light of tech that improved. Before better fan motor tech and a good dual setup arrived in Gen-4, and the expensive Hydraulic system in Gen-3, everything they tried was a problem in Gen-1 & 2, with their common overheating and wiring meltdown issues.

"Just because something works, doesn't mean its right, without downsides, or functional issues"

I think I'll step off my soapbox now, as it seems you're gonna do what you're gonna do regardless. This isnt an iron V8 or a car with a huge radiator and opening that barely needs any airflow to cool. Its got more in common with stationary loaded heavy-equipment cooling issues than a typical car.

Ok now we're getting somewhere. What went wrong with the Ram SRT10 trucks that converted to electric?

I don't want to fart in the wind, so you're saying I need more airflow. What is the CFM for a Gen 4, I'll use that as a reference point.

Do you have a link or price estimate for the required parts to repair the hydraulic system, so I can weigh both options.

Gen 4 conversion is not an option at this point, so in your opinion, what would be needed to do aftermarket fans properly?

 

[Viper Specialty]

Ok now we're getting somewhere. What went wrong with the Ram SRT10 trucks that converted to electric?

Simple, they all had overheating issues when not traveling at speed. And thats a RAM, with a HUGE radiator and ducting system.

I don't want to fart in the wind, so you're saying I need more airflow. What is the CFM for a Gen 4, I'll use that as a reference point.

Actual numbers aren't published, but I would expect it in the 3500-4500 range.

Do you have a link or price estimate for the required parts to repair the hydraulic system, so I can weigh both options.

I would estimate you would be in the 1000-1250 range to fix it all properly, pending how much damage there is done to your existing fan motor and whether I can repair it or if it needs to be replaced.

Gen 4 conversion is not an option at this point, so in your opinion, what would be needed to do aftermarket fans properly?

You would need a pair of high-end brushless SPAL fans, a custom made shroud with flaps, PCM modification, PDC and Relay center, wiring harness, Gen-4 pump and reservoir, Gen-4 hydraulic line, and installation.

And that parts list in no way, shape, or form will come in anywhere near 1250 bucks, even at my wholesale.

 

[Fatman2006]

Two questions.

Does anyone know what size the fans are on Gen 4?

What are the biggest fans I can fit in the space?

Thanks.

 

[99RT10GTS]

Two questions.

Does anyone know what size the fans are on Gen 4?

What are the biggest fans I can fit in the space?

Thanks.

You're not paying attention. VSP will show up and school you again.......................... Hang on.................... Here he comes now...........

 

[Viper Specialty]

You're not paying attention. VSP will show up and school you again.......................... Hang on.................... Here he comes now...........

Actually, you're about as anti-hydraulic as he is, so why don't you spend your time helping him out?

I am waaaay over my allotted time for the month trying to save people from themselves.

 

[Fatman2006]

Actually, you're about as anti-hydraulic as he is, so why don't you spend your time helping him out?

I am waaaay over my allotted time for the month trying to save people from themselves.

I love hydraulics!

Come on old man, I know you have it in you to give me the information

 

[Fatman2006]

So I definitely did the electric conversion. I ran a single hydraulic line from the pump to the rack. I capped off the oil cooler return at the power steering reservoir.

I then spliced the return from the oil cooler into the half inch return that was for the hydraulic fan and connected that to the reservoir.

I'm using a PWM to control a 12in and 10in electric fan. I had a custom aluminum radiator shroud fabricated to replace the stock shroud. I don't have the relief vents cuts yet, but that's on the way.

I used a temp probe plumbed into the radiator inlet to capture temps for the PWM. I dropped the thermostat to 160°.

I'm in the testing phase at this moment. First test PWM was set to 160° fans came on at 10% and climbed according to coolant temp. I let the car idle for 15 minutes and max temp was 167°. Obviously too cold.

I then took the car for a 7 minute drive ambient temp 65°. 1st and 2nd gear pulls, max temp reached was 185°. I parked the car and let it idle for another 5 minutes, temps dropped to 176°.

The issues I'm going to address. I have a max target temp of 190° so I'll adjust the PWM to reach that. The second issue which will be resolved in conjunction with the first issue, the fans stayed on after the car was off, chasing 160°. I'll set my activation temp higher and that should resolve both problems. I'll keep you guys posted. Thanks for all the input and advice along the way!

I'll let you know if my car blows up.

 

[99RT10GTS]

So I definitely did the electric conversion. I ran a single hydraulic line from the pump to the rack. I capped off the oil cooler return at the power steering reservoir.

I then spliced the return from the oil cooler into the half inch return that was for the hydraulic fan and connected that to the reservoir.

I'm using a PWM to control a 12in and 10in electric fan. I had a custom aluminum radiator shroud fabricated to replace the stock shroud. I don't have the relief vents cuts yet, but that's on the way.

I used a temp probe plumbed into the radiator inlet to capture temps for the PWM. I dropped the thermostat to 160°.

I'm in the testing phase at this moment. First test PWM was set to 160° fans came on at 10% and climbed according to coolant temp. I let the car idle for 15 minutes and max temp was 167°. Obviously too cold.

I then took the car for a 7 minute drive ambient temp 65°. 1st and 2nd gear pulls, max temp reached was 185°. I parked the car and let it idle for another 5 minutes, temps dropped to 176°.

The issues I'm going to address. I have a max target temp of 190° so I'll adjust the PWM to reach that. The second issue which will be resolved in conjunction with the first issue, the fans stayed on after the car was off, chasing 160°. I'll set my activation temp higher and that should resolve both problems. I'll keep you guys posted. Thanks for all the input and advice along the way!

I'll let you know if my car blows up.

VSP will surely expect your car to blow up very soon because you didn't take his idiotic advice.

If you can take pictures and post them up, it will help other Gen 3 guys fix a known issue without having VSP steer them to spending a buttload of money with his great advice.

 

[Viper Specialty]

VSP will surely expect your car to blow up very soon because you didn't take his idiotic advice.

If you can take pictures and post them up, it will help other Gen 3 guys fix a known issue without having VSP steer them to spending a buttload of money with his great advice.

You're a complete *****.

Spending a boatload of money? STICKING WITH OEM AND KNOWING WHAT YOU ARE DOING WOULD HAVE COST LESS THAN 100 BUCKS TO SOLVE ALL OF THIS FROM THE GET GO.

But yeah, I'm the one costing people money by telling them to NOT do things or buy things they dont friggen need. G. F. Y.

Go sell some more broken crap to people.

 

[99RT10GTS]

 

[Fatman2006]

VSP will surely expect your car to blow up very soon because you didn't take his idiotic advice.

If you can take pictures and post them up, it will help other Gen 3 guys fix a known issue without having VSP steer them to spending a buttload of money with his great advice.

I'll post some pics when I get home, .

You're a complete *****.

Spending a boatload of money? STICKING WITH OEM AND KNOWING WHAT YOU ARE DOING WOULD HAVE COST LESS THAN 100 BUCKS TO SOLVE ALL OF THIS FROM THE GET GO.

But yeah, I'm the one costing people money by telling them to NOT do things or buy things they dont friggen need. G. F. Y.

Go sell some more broken crap to people.

Genuine question, the hydraulic unit costs less than $100?

I think it's important to explain why I decided to do the conversion.

Last time a power steering line ruptured I was away from home. I had to leave the car in a parking lot not because I couldn't steer the car, but because I was worried it would overheat.

There is value in separating the power steering from the cooling. Now if I lose power steering I don't lose both systems.

Everything else is secondary to that benefit. I'm not an engineer or mechanic but it's extremely easy to read schematics to understand what's going on and what needs to be changed.

Wiring a PWM and fans is super easy, have a shroud fabricated easy, have a single hydraulic line fabricated easy. By the way that hydraulic line cost about $72 and is rated at 2500psi. You're not finding a Viper line for that price anywhere.

The two most difficult tasks in this conversion were deciding which fans would be suitable and getting the aluminum adapter in the coolant line. That was only difficult because I went with a 2.5in adapter (would not recommend) and not a 2.25in.

I went with brushed fans for PWM compatibility, and brushless have a massive Amp draw which would require a Gen 4 alternator.

Just going off touch, the first fan, 12in, draws so much heat away the air coming out of the 10in is noticably cooler. This is supported by the fact the highest temp I saw was 185°, which also means the fans never reached 100% output. I have plenty of overhead for keeping the car cool.

All said and done this is a very straightforward and simple conversion. It may not be for everyone, but at the end of the day the point of a cooling system is to keep the car in an operating temperature range so I can enjoy my car worry free. Objective achieved.

I live in Arizona so there will be ongoing testing through summer time, but if this setup can survive in AZ it will get the job done in any state.

 

[Viper Specialty]

I'll post some pics when I get home, .

Genuine question, the hydraulic unit costs less than $100?

No, I meant that your entire situation was started over a fitting leak, which could have easily been replaced. But instead, hydraulic lines were replaced, which ultimately started your cascade of headaches.

Lack of knowledge by both owners and vendors is responsible for literally 99% of these types of issues. Some of it is ignorance, but a lot is also intentional to make sales.

 

[Fatman2006]

No, I meant that your entire situation was started over a fitting leak, which could have easily been replaced. But instead, hydraulic lines were replaced, which ultimately started your cascade of headaches.

Lack of knowledge by both owners and vendors is responsible for literally 99% of these types of issues. Some of it is ignorance, but a lot is also intentional to make sales.

Makes sense and I agree. Unfortunately, I was already down that road so there was no point in back tracking. If this electric system doesn't work, I'm doing a full Gen 4 electric conversion, because why not

A couple other notes I found along the way. Gen 3 fan 17 in, Gen 4 dual 13 in. Both Gen use curved blades for noise reduction, this is done at the expense of CFM.

I'm using paddle blades because I don't care about noise and want maximum CFM. At face value there is a total of 3 inch difference between me 23in and Gen 4 26in. That 3 inch difference should be offset in CFM based on superior blade design on my fans.

My 12 inch fan is definitely moving more air then 1 of the 13in fans on a G4, and my 10in fan should be relatively close but most likely not flowing as much. However, that should be made-up for with the higher 12in CFM.

 

[Steve M]

It might be better to think about it in terms of total area rather than blade diameter.

17" fan: ~227 sq. in.
13" fan: ~133 sq. in.
12" fan: ~113 sq. in.
10" fan: ~79 sq. in.

Two 13" fans = ~266 sq. in.
One 12" + one 10" fan = ~192 sq. in.

Obviously there's more to fans than just area (blade shape, pitch, RPMs), but two 13" fans cover a lot more area (74 more square inches) than the seemingly small 3" difference in total diameter would imply.

Does anyone have the CFM data for the Gen 3 and Gen 4 fans (each fan)?

 

[Fatman2006]

It might be better to think about it in terms of total area rather than blade diameter.

17" fan: ~227 sq. in.
13" fan: ~133 sq. in.
12" fan: ~113 sq. in.
10" fan: ~79 sq. in.

Two 13" fans = ~266 sq. in.
One 12" + one 10" fan = ~192 sq. in.

Obviously there's more to fans than just area (blade shape, pitch, RPMs), but two 13" fans cover a lot more area (74 more square inches) than the seemingly small 3" difference in total diameter would imply.

Does anyone have the CFM data for the Gen 3 and Gen 4 fans (each fan)?

I feel like this is a learning point for me. Wouldn't you need to know blade dimensions to calculate the surface area?

For example: A 17 inch fan with 5 blades that are 2 inches wide would not have ~227 sq in surface area.

Conversely for example, my 12 in fan with 5 that are much wider than the blades on both G3/4 would have more surface area.

Make this make sense for me.

I asked about CFM for Gen 3/4 fans no one has the data. I was able to find actual bench testing for a group of other fans for reference points but that was as close as I could get.

 

[Steve M]

I feel like this is a learning point for me. Wouldn't you need to know blade dimensions to calculate the surface area?

For example: A 17 inch fan with 5 blades that are 2 inches wide would not have ~227 sq in surface area.

Conversely for example, my 12 in fan with 5 that are much wider than the blades on both G3/4 would have more surface area.

Make this make sense for me.

I asked about CFM for Gen 3/4 fans no one has the data. I was able to find actual bench testing for a group of other fans for reference points but that was as close as I could get.

My calculations would only account for the swept area for each fan. I'm not sure if that's the most important aspect or not (I'd think it'd be up near the top though), but I've never really thought about it past a surface level.

I'll have to do some thinking about the effects of other fan characteristics; e.g., more blades, tip velocities, etc. Likely way more complicated than just finding CFM specs, but I'll do some digging.

 

[Fatman2006]

Aluminum fan shroud with 12 inch fan on driver's side, 10 inch on passenger side.

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Single power steering line and capped off return line.

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PWM controller.

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You can't see it in any of the pics, but there is a rubber seal around the shroud, sealing it to the radiator.

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All cleaned and buttoned up.

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Today's test.
Ambient temp 75°.
Activation temp 170°
Fans on at 170° at 10% power
Idled for 15 minutes maintained 177.6°
7 minute test drive with 1st and 2nd gear pulls
Max temp hit 200° for a blink of an eye before dropping to 197.4°
Parked and idled for 5 minutes temps dropped to 185.7° and maintained until car was turned off.

Not pictured is the power steering oil cooler return splice. But it's a black aluminum ⅜ to ½ inch barbed adapter. I cut the outlet hose from the PS oil cooler return ⅜ inch, and spliced it into the ½ inch return that was used for the return from the hydraulic fan pump. Then I capped the none functioning PS cooler line at the reservoir with a barbed ⅜ inch hose plug.

All this is proof of concept, I will get a Gen 4 reservoir so it only has one return line, and I'll get an aluminum radiator so I can move the temp prop to the radiator.

Any feedback on my temps would be greatly appreciated.

 

[GTS Dean]

Gotta respect a man who goes boldly against popular wisdom and triumphs. So far, so good. Let us know how it works this summer, and with track loads. Probably going to need some refinement, but you seem up to the task. You do plan to replumb some steering cooling, right?