So in your opinion there is enough horsepower/mpg gain to switch from clutch to e-fan? If so I will be looking forward to you findings. Also I pull alot of power with my sound system,(even with a capacitor lights still blink) would I be doing more harm then good by switching? meaning amps wise.

Mike

 

I don't believe there is a huge dif in H.P./mpg gains. I'll dyno before/after to show the difference. Amp draw is huge to me too, which is why I'm going for a single fan set up.

I can't give tips on mpg, don't pay attention to my mileage. I'm doing the upgrade to help the truck warm up in winter, and improve the a.c. in city driving.

EDIT. If your lights are already blinking with the system, I would look at a larger alternator before doing anything with an electric fan.

 

First thing I want to say, is my hat is off to Hutch! You are kicka$$! Im goin to put an e-fan setup on my truck as soon as I get back to alaska. I agree with hutch that the shroud will make a difference.
One question, Im going to build a sheetmetal shroud for my setup. I dont know exactly how Im goin to do it b/c I havent seen my truck in 11months. What would the ideal distance from the radiator to the fan be?
When I get it made, Ill make sure to put up drawings and specs on how to build it. Shouldnt be too difficult if you have access to a break or can use your imagination. It might take a while, b/c Im going to be building it from scratch and I want to make sure that it mounts the overflow and wiper fluid bottles.

 

one question, one statement.

Question: If the radiator surface area is larger than the fan, and you use a shroud, doesn't the resistance against the fan relax? you do have fins and whatnot, but you've increased the amount of available surface to draw from, so the restrictions should relax.

Statement. I have a proform 16" puller and 14" pusher fan, and have never, ever overheated with them operating correctly. I have them strapped straight to the rad with no shroud. The 14" pusher does very little cooling of the radiator, the 16" once turned off because I foolishly let the cord dangle loose and the connections wiggled apart. I watched the tranny temp gauge go from 155 to 180 in 5 minutes, that's what freaked me and I pulled over and discovered the issue. I can run but just a little hot with the 16" by itself.

 

With or without the shroud, the fan, mounted to the radiator, is really only going to pull from that 16" diameter, and basically that 16" area of the radiator. What the shroud is going to do is help (this is my theory on this, and might be proved wrong with testing) is help stabilize the inlet and outlet pressures, and could give a bump in performance. Going into this, I believed that I could mount the fan back in the shroud, closer to the stock mech. fan location, and change the resistance like you are thinking, which could increase the airflow. After looking at the fan blade design, I am no longer confident that will work.

Something to keep in mind, when fans are designed you choose the size/pitch/location of the blades to work against certain static resistances. My thinking is they designed the fan to be mounted up against the radiator, and it needs that higher inlet static pressure to move x amount. I think because of that, losing that static pressure could hurt performance. I will be chamber testing with and without shrouds, and playing with locations to see what I come up with.

As far as your set up, seems to prove to me what I think I'll find with the Proform fans. I think they 2100 is going to be closer to 1600 on the 16", but you're making up for it with the 14'' pusher, getting you up to the 2000+ we should have.

Still want to find a single fan to do both. I won't do anything with pusher fans because all the recomendations I've seen state that when a fan is a pusher vs puller, it loses 20% of it's max airflow. It's working for you, but I want to find a single fan with the least amount of amp draw because I have the stereo system, so I want to keep my amps down.

One of my goals of this was to find a low dollar/amp electric fan set up for these trucks, and think the $300+ guys have paid is too much. Guessing you don't have that into your set up, so you're already halfway there. I haven't tested squat yet, so my dream of 2000 cfm at an amp draw of close to 10 amps might be impossible. Once I get up to a fan that pulls 2k, might be a similar amp draw to what you have, and literally be no different.

So basically, after all this screwing around, I might only prove you have the best option..lol

 

Maybe, but at least you got the numbers to back it up, and didn't just go off what some guy told you, like I did.

 

To specifically answer your question about shroud design, that's tricky. The factory shroud is designed to end at a specific point in relation to the stock fan. That specific design is what allows the fan to pull the air through the radiator. It actually creates a bit of a suction s.p., but the stock fan is designed with that in mind. At idle, we pull under 1000 cfm through the radiator. When you take the stock shroud off, the fan is no longer doing that, and you'll be lucky to get half that through the radiator.

Every electric fan design is going to have a different reaction to a shroud. I'll test all the fans I mess with both on the radiator, and back away to see if there is any sig. difference, and hopefully you can make some determinations off of that.

EDIT. Since you live in Alaska, I wouldn't worry about a shroud. You're temps won't make it a needed component.

 

How long you had that set up anyway? Remember seeing that when I was checking out different fan threads. Happen to know the model numbers on the fans?

 

Purpose of fan shroud:

My theory - Mounting a round fan directly to a rectangular radiator doesn't maximize the cooling ability of the radiator because only part of the radiator is getting full air flow. So, the shroud allows the fan to pull air thru the rad more evenly, thus maximizing the cooling.




I slept at a Holiday Inn express last night.

 

You are right, however if the fan doesn't have the power to overcome the distance from the radiator to the location at the rear of the shroud, and airflow is less as a result, you are doing more harm then good.

I do hope to find a fan that can mount at the rear of the shroud and work, give me fairly equal feet per minute velocities across the face of the radiator, and in turn maximum heat transfer, but I don't believe I will. Best way to do that would probably be with 2 smaller fans.