LS1 Electric Fans...anyone done?

MarkD · April 18, 2002

Has anyone done this mod. I am thinking about it, but curious as to what is involved.

gandolphxx · April 18, 2002

Interesting topic, one I am researching for my 8.1L. I have had electrics on my Jeep GC 5.9L for four years, no problems - great in hot wheather.

What I have found to date:

1. Flex-a-Lite makes a 260 and now 280 dual fan set that pulls 5500 cfm, the 280 is variable speed - temp control and AC relay - about $400 - those that have them seem happy, other than the price.

2. Perma-Cool also makes a dual fan set for trucks.

3. A number of folks are using LS1 &/or LT1 fans from scrap or auction to do the same thing - need to cobble up mounting brackets and wiring harness, relay, and temp control.

4. References to Lincoln Mark VIII fans and Ford Windstar fans being used also - still digging on those.

Lots of yeas and nays on doing this mod - if it is sloppy, could hurt the engine. Most want the additional power for drag racing.

I have seen references to not using them for heavy tow applications - no reason, can't give you one.

Last, but not least, consider beefing up your alternator - the typical 105/130 is not going to like the load - go to a 200, that will give you the amps at idle, which is where you need them.

July 31, 2002

Im looking in to doing this very same thing...Im going to try to go with the ls1 fans because I think they bolt right up... But Ive yet to call a GM dealer though to check on prices. Should be a good mod for both power and mileage.

;) So Ill keep yall up to date as soon as I get those prices.

gandolphxx · August 1, 2002

The Flexalite 282 is a good option to consider also, easy install and all the parts are ther in the package.

CMNTMXR81 · August 1, 2002

I've been contemplating this too. The issue on towing is that the pulley mounted fan is spinning as long as the engine is running. I.E., if you're towing, the fan is constantly spinning therefore drawing air through the radiators/coolers.

An electric fan setup would only turn the fans on when they reach the preset temp and turn off when they reach the preset cool turn off temp. Anotherwords, they aren't on all the time.

It's simply a safety valve so to speak.

Another issue, is that on electric fan cars, whenever the A/C is turned on, or you turn on your defroster (which engages the A/C compressor) it automatically turns on the low speed fan as a safety mechanism. Since our trucks having pulley fans from the factory, I'd look into this little detail to see if and how we could incorporate it.

August 1, 2002

What does it matter if your fans turn off and on? That way they keep your engine around the same temp... (I.E.. Turn off when they reach a low temp.. and turn back on when they reach a lil higher temp... ) I know you understand that but I just dont see how that could be a problem being that, well, thats what theyre supposed to do. Keep your engine at or around a good operating temp... Besides that.. All of the aftermarket electric fans Ive seen are designed to run constantly, (via running off of the ignition).

gandolphxx · August 2, 2002

Thed Flexalite package is variable speed - handles the demand from the AC and is not tied to the ignition for always on. If you get the LT1 fans, you need to do all of that from scratch.

CMNTMXR81 · August 2, 2002

What does it matter if your fans turn off and on? That way they keep your engine around the same temp... (I.E.. Turn off when they reach a low temp.. and turn back on when they reach a lil higher temp... ) I know you understand that but I just dont see how that could be a problem being that, well, thats what theyre supposed to do. Keep your engine at or around a good operating temp... Besides that.. All of the aftermarket electric fans Ive seen are designed to run constantly, (via running off of the ignition).

I think you missed my point.

All GM vehicles with electric fans, when you turn on the A/C or defroster have a safety mechanism in the system which automatically turn on the low speed fan. The reason for this is because the A/C compressor is engaged therefore causing more drag/load on the engine. Like I said, it's simply a safety mechanism. If you don't want it and want it to be completely controlled by the thermostatically controlled switch, fine. I'd like mine to work like the factory systems. GM engineers believe it or not have some sort of logic behind everything they do.

August 2, 2002

I understand the whole AC/ Low speed fan dilemna.. And never did I doubt the GM engineers. I just misunderstood what you were getting at with that whole deal... I just thought you were getting at that it wasnt good for the fans to be on and off and on and off... I figured what the #### did it matter if it was keeping the engine at the same temp? With the LS1 fans aside, most other setups ive seen were a single fan that ran off the ignition being on: keeping them running the same constant speed. Sorry 'bout not being thorough in my reading and responding. :blush: Regardless of that; looks like the flexalite that gandolph is talking about would be ideal.

mnstrmdnss · August 3, 2002

sounds like the flex-a-lite fans you are talking about is the "black magic" fans, choice of a single(2800cfm) or dual(5600cfm) 15" fan.i have dual electric fans on my sonoma(one goes on for cooling and both go on for a/c operation), and i think the only way way to go is with an adjustable relay(i got mine at advanced auto for 30 bucks), cause if thier wired to go on when the ignition is on, then thats jsut extra strain on th alternator and exessive use of the fan motors, so have them hooked up to a thermostat. plus, on a bigger note, they really really need to be hooked up to the a/c compressor to kik on, cause if they are just hooked to a thermostat and not the a/c, then you could potentially blow out the compressor by not getting any air across the condensorplus thier wont be any cold air inside until yo get moving about 50mph, and a new compressor will cost about $800-$1000 to get installed, trust me, i made the same mistake when i first pulled off my steel fan and had jsut 1 fan hooked up to only a thermostat, and not the a/c, i ruined 2 a/c compressors so far, until i rewired right, now two 16" electric fans kick on when i turn on the air, plenty of cold air inside.

its a really good modification if you spend the money and get good parts, and do it right. it'll save on gas, and give you about 10-20 hp more.

gandolphxx · August 3, 2002

What I am referring to is the new Flex-a-lite 270/280 dual. variable speed fan kit, not the Black Magic set.

Dual 15" blades move 5500 CFM!

Includes new Variable Speed Control

(60% to 100% depending on cooling required)

Glass reinforced nylon injection

molded shroud

Dyno tests showed a gain of 17HP & 20 Ft. Lb. torque at the wheels

Improves gas mileage

Quicker warm-up & cool-down

mnstrmdnss · August 4, 2002

ive seen them, looks like the same blades and casing used in their black magic series.

the variable option sounds really cool.

MarkD · August 4, 2002

OK, now who else is trolling for vendors for the flex-a-lite?

I can't really find any. The Flex-a-lite model for the newer GM trucks is 282.

CMNTMXR81 · August 5, 2002

I understand the whole AC/ Low speed fan dilemna.. And never did I doubt the GM engineers. I just misunderstood what you were getting at with that whole deal... I just thought you were getting at that it wasnt good for the fans to be on and off and on and off... I figured what the #### did it matter if it was keeping the engine at the same temp? With the LS1 fans aside, most other setups ive seen were a single fan that ran off the ignition being on: keeping them running the same constant speed. Sorry 'bout not being thorough in my reading and responding. :blush: Regardless of that; looks like the flexalite that gandolph is talking about would be ideal.

Sounds good. I'd be more inclined to get the flex-a-lite as I know they have a good reputation. I saw another one (can't remember the manufacturer) on Performanceproducts.com that says it bolts right up to the stock fna housings, etc. But it looked real cheesy and cheap.

I could see some nice power gains being made from an electric fan setup!

badpewterz · August 7, 2002

i put lt1 fans in my sierra a few weeks ago and cant be happier, using a thermo switch and manual override switch which can be wired to the a/c compressor if you want, no problems yet , gained some low end and runs cooler too

my lt1 fan page