Deleted my mechanical fan and gained HP & MPG

by "Boosted2k - I Make Videos and Put Them on YouTube" (boosted-2k)
Published 11/07/2017 at 14:14

Tags: Dodge ; ram ; 1500 ; 4x4 ; hemi ; 5.7l ; mpg ; increase ; hp ; miles per gallon ; savings ; fuel ; fuel savings ; fuel mileage ; mileage ; diy ; how to ; mod ; do it yourself ; modification ; horsepower ; mopar ; 5.7
STARS: 7

Why the hell do vehicles still come with mechanical fans? It’s kind of amusing to see the logic that goes into vehicle that are designed today.

More specifically the pickup truck sector. They are faced with the difficult task of trying to use advancements in technology and engineering to make a better vehicle without pissing off people that don’t want change or more electronics or things that can fail on their truck. Case and point is the mechanical fan.

The 09+ 1500 RAM HEMI trucks come with a clutched mechanical fan running off the waterpump pulley and an electric backup fan to supplement it.

The V6 model on the other hand uses a MASSIVE electric fan to cool the exact same radiator and helps that little engine to be quite fuel efficient too.

So here comes the mod. On a 09+ RAM 1500 HEMI you can delete the mechanical fan, huge shroud, and small electric fan. In its place you gain almost 2 feet of engine room and put a OEM denso fan that is plug and play.

The only caveat is you need a tuner to change the fan ON setting lower to kick in around 200* instead of the 220* it is currently set to when the mechanical fan can’t do its job.

The final product is WAY more room to work in the engine bay and I have noticed more fuel mileage and also a bit more power in the seat of the pants. Also got rid of that annoying ROAR of the mechanical fan on a cold start that everyone knows.

What’s your thoughts? Why didn’t this come stock? Was it to keep the old timers happy? Discuss!

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Replies (34)

"OPPOsaurus WRX" (opposaurus)
11/07/2017 at 14:20, STARS: 2

i did that too however the fan controller POS was also shot so i had to run a manual switch inside the cabin which for a long time was a regular light switch you would use in a house.

"Chuck 2(O=[][]=O)2" (pompei426)
11/07/2017 at 14:26, STARS: 4

Mechanical fans suck. Here’s a somewhat-recent episode of HR’s Engine Masters testing fan’s parasitic drag. Check it out!

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"RamblinRover Luxury-Yacht" (ramblininexile)
11/07/2017 at 14:30, STARS: 8

I have two vehicles with unclutched mechanical fans. ROOOOOOOOOARARAAAARRRR

"Urambo Tauro" (urambotauro)
11/07/2017 at 14:31, STARS: 0

Didn’t the R34 GT-R have a mechanical cooling fan? Blows my mind.

"HammerheadFistpunch" (hammerheadfistpunch)
11/07/2017 at 14:32, STARS: 4

Mechanical fans are generally preferred off-road but that is going away too as electric fans have become much more durable. I still like my mechanical fan because its run off a fully redundant fan belt so I can brake a belt and still have engine cooling.

"Rustholes-Are-Weight-Reduction" (rustholes-are-weight-reduction)
11/07/2017 at 14:36, STARS: 0

You are objectively right, but my current line-up of 5 cars doesn’t have one electric fan

"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
11/07/2017 at 14:37, STARS: 2

The Jag now has the electric fan from a 3.8 V6 early 90s Taurus (4000cfm dual speed) with a custom relay setup. At idle that car is quieter than any modern econobox. A slight whirr from the engine bay and a muted V8 rumble from the rear. It’s nice.

"Rusty Vandura - www.tinyurl.com/keepoppo" (rustyvandura)
11/07/2017 at 14:39, STARS: 0

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"Sweet Trav" (thespunbearing)
11/07/2017 at 14:40, STARS: 0

^ This.

"Sweet Trav" (thespunbearing)
11/07/2017 at 14:41, STARS: 1

You don’t even want to know what a water pump or PS pump takes away...

"crowmolly" (crowmolly)
11/07/2017 at 15:03, STARS: 0

If I remember correctly mechanical fans are good off road due to high rpm/low speed situations where they can move more air than electrics.

"HammerheadFistpunch" (hammerheadfistpunch)
11/07/2017 at 15:07, STARS: 0

Thats also the case. They have some disadvantages off road like pulling the blades into the rad in water and chomping the rad but its really only an issue if the bay is really tight anyway.

"Boosted2k - I Make Videos and Put Them on YouTube" (boosted-2k)
11/07/2017 at 15:07, STARS: 1

Ah so you can share my strange sense of joy of not having to hear that damn mechanical fan whirring anymore lol

"Boosted2k - I Make Videos and Put Them on YouTube" (boosted-2k)
11/07/2017 at 15:10, STARS: 0

Yeah I agree and this goes back to that old saying “if ain’t broke don’t fix it”. Most of the modern mechanical fans are belt driven from a serpentine off the crank pulley so its a crapshoot either way. Most vehicles are cooled with an electric fan these days so really its a non issue. All modern Jeeps have electric fans and they are built for offroad...

"Boosted2k - I Make Videos and Put Them on YouTube" (boosted-2k)
11/07/2017 at 15:12, STARS: 0

Finding the right controller is almost half the battle and definitely worth it to spend on a reliable one! I got lucky and mine was a direct plug in replacement on the factory harness/ecu :D

"Boosted2k - I Make Videos and Put Them on YouTube" (boosted-2k)
11/07/2017 at 15:13, STARS: 1

lol exactly! Why the fan would fully engage on a cold start up is also mind boggling.

This is the sound of my people....hear me “ROOOOOARR” :D

"OPPOsaurus WRX" (opposaurus)
11/07/2017 at 15:22, STARS: 0

mine was too, its just that the existing one was broken.

"Rock Bottom" (rockbottom81)
11/07/2017 at 15:27, STARS: 4

The reason we use mechanical fans on trucks is because of one simple test that every American auto maker performs: Davis Dam. This test is simple: On a hot day, load the vehicle to max GVW including a large and un-aerodynamic trailer, put the AC on max, and drive up Davis Dam as hard as you can. An electric fan able to drag enough air to pass that simple test would have to be insanely powerful. Thousands of watts. A mechanical fan is the better choice for a truck. Cars MGVW are much lower and the road load horsepower is way lower than in a truck, so they can (usually) get away with a smaller electric fan.

Fun fact: in Europe they often use an Austrian mountain called Grossglockner for the same purpose. These two climbs are among the hardest tests the thermal systems guys have to contend with.

http://www.trucktrend.com/how-to/towing/1502-sae-j2807-tow-tests-the-standard/

Sincerely, automotive engineer

"KusabiSensei - Captain of the Toronto Maple Leafs" (kusabisensei)
11/07/2017 at 15:36, STARS: 1

My Benz had the other failure mode with viscous clutch for the fan... It never would lock up, no matter how hot it gets.

The Duramax on the other hand? I get the distinct impression that it’s trying to move the truck not by torque on the drivetrain, but rather by turning the fan quickly enough.

"KusabiSensei - Captain of the Toronto Maple Leafs" (kusabisensei)
11/07/2017 at 15:39, STARS: 0

At least that’s usually less than a supercharger...

"Demon-Xanth knows how to operate a street." (demon-xanth)
11/07/2017 at 15:44, STARS: 0

On my 02 Dakota, the clutch fan was the backup. It only went into effect if things got really hot or for a minute on cold mornings.

"RamblinRover Luxury-Yacht" (ramblininexile)
11/07/2017 at 16:39, STARS: 3

The clear solution here is to float your truck into the air with a balloon and use the fan + meredith effect shields on the engine compartment and exhaust to propel yourself. For science. You monster.

"Sweet Trav" (thespunbearing)
11/07/2017 at 16:39, STARS: 0

well, think of it this way, the surface of the fan is larger than a water pump impeller blade, but the smaller impeller blade is circulating pressurized fluid, significantly more dense than air...

"cmill189 - sans Volvo" (cmill189)
11/07/2017 at 16:47, STARS: 0

That change in power is even more noticeable on a low-powered vehicle. In Subaru’s infinite wisdom they switched from an electric to a mechanical when they changed from the EA81 to EA82 engines back in the ‘80s....but only for A/C equipped cars. Non-A/C cars used a single electric like they always had. I retrofitted one from an older car and the sound and feeling of the engine transformed. I used to have a Yukon with a clutched fan and I always wanted to swap it out every time cold weather hit. The roaring is the worst.

"The Powershift in Steve's '12 Ford Focus killed it's TCM (under warranty!)" (steve-still-hasnt-wrecked-the-powershift-in-his-12-ford-focus)
11/07/2017 at 16:50, STARS: 3

I’m not sure what it is with those 3.8L Taurus fans, but they seem like THE electric fan to swap into anything that doesn’t have an electric one. I’ve seen them in Fieros, 3rd gen Camaros, Miatas, and more.

"Future next gen S2000 owner" (future-next-gen-s2000-owner)
11/07/2017 at 18:11, STARS: 0

Anyone know if someone has down this on the 16+ Tacoma?

"KusabiSensei - Captain of the Toronto Maple Leafs" (kusabisensei)
11/07/2017 at 19:41, STARS: 0

I see no issue with this.

"KusabiSensei - Captain of the Toronto Maple Leafs" (kusabisensei)
11/07/2017 at 19:46, STARS: 0

At least there’s been a movement towards EPAS to at least get one of the fluid pumps off the crank.

The only thing is that a universal rack with EPAS to replace a hydraulic rack (i.e. if you re-engine with something like a Gen V LT1) is $2000. It’s worth it though.

"lone_liberal" (token-liberal)
11/07/2017 at 19:54, STARS: 1

That episode made me finally get off my ass and replace the Camaro’s non-clutch mechanical fan with an electric one that I already had but had put off installing.

"Full of the sound of the Gran Fury, signifying nothing." (granfury)
11/07/2017 at 20:24, STARS: 1

What is this ‘fan shroud’ thing to which you refer?

"JGrabowMSt" (jgrabowmst)
11/07/2017 at 22:21, STARS: 0

I have a clutched mechanical fan in the SL. I need to change the clutch before it explodes.

"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
11/07/2017 at 22:24, STARS: 1

SBC Jeep guys love them. It’s just some weird case of an afterthought item in a beige-ass car randomly ending up being obnoxiously good and sought-after in junkyards. Mine was $40. Love it.

"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
11/07/2017 at 22:24, STARS: 0

My 5 speed V6 fox body had a mechanical fan and I hated it because that little V6 actually had a decent exhaust note through the aftermarket exhaust but I couldn’t hear it over the roar of that dumbass fan.

"RacingShark" (racingshark)
11/15/2017 at 12:49, STARS: 0

Motor Trend’s Engine masters series of videos did a comparison of different types of mechanical fans. I was blown away (see what i did there?) by how much power mechanical fans use. I think they saw like a 30hp drop from a mechanical fan.

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