Electric vs Mechanical fan cfm

flash7210 · **Posted:** Fri Jul 18, 2014 9:34 am

Towing 5000 lbs, up a hill, in Arizona, in the summer, would be the ultimate test.

I think under those conditions it would be best to have the mechanical fan with hayden
clutch. Keeping vehicle speed at about 58mph in 4th gear, engine at 1900- 2000 rpm to
keep the fan speed up.

mass-hole · **Posted:** Fri Jul 18, 2014 9:46 am

flash7210 wrote:

Towing 5000 lbs, up a hill, in Arizona, in the summer, would be the ultimate test.

I think under those conditions it would be best to have the mechanical fan with hayden
clutch. Keeping vehicle speed at about 58mph in 4th gear, engine at 1900- 2000 rpm to
keep the fan speed up.

If the engine is spinning that slow, wouldnt the electric fan be more useful since you could run it at max regardless of engine speed?

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

mass-hole wrote:

flash7210 wrote:

Towing 5000 lbs, up a hill, in Arizona, in the summer, would be the ultimate test.

I think under those conditions it would be best to have the mechanical fan with hayden
clutch. Keeping vehicle speed at about 58mph in 4th gear, engine at 1900- 2000 rpm to
keep the fan speed up.

If the engine is spinning that slow, wouldnt the electric fan be more useful since you could run it at max regardless of engine speed?

The hot trailer tow testing bogey for most OEMs is the grade near Davis Dam. The goal is 100F, 5000lb. trailer with 50+ sq.ft. trailer frontal area, AC on for the Liberty. With stock hardware, the engine temps creep up during the first portion of the run, mechanical fan is fully engaged throughout the run. Just a couple miles into it the coolant gauge is next to the red zone and the engine is depowering to reduce heat load to coolant. This makes the vehicle slow down to a point where it downshifts to 3rd lockup and in some cases 2prime lockup. The engine rpm is over 3000 and the vehicle continues on up the grade at about 35-45mph. If the AC is off the KJ will go up the grade at 55mph. Davis dam speed limit was 65mph, so it is a major test. The melted asphalt on the shoulder in spots from vehicles burning to the ground it a testament to how hard this route is.

The KJ water pump does not flow very well and it seems to cool better in extreme conditions when the engine rpm is above 2700rpm.

flash7210 · **Posted:** Fri Jul 18, 2014 12:39 pm

mass-hole wrote:

flash7210 wrote:

Towing 5000 lbs, up a hill, in Arizona, in the summer, would be the ultimate test.

I think under those conditions it would be best to have the mechanical fan with hayden
clutch. Keeping vehicle speed at about 58mph in 4th gear, engine at 1900- 2000 rpm to
keep the fan speed up.

If the engine is spinning that slow, wouldnt the electric fan be more useful since you could run it at max regardless of engine speed?

I suppose your right.
The point is that you should not be charging up the hill at 65mph in 5th gear.
You should slow down and stay in a lower gear.
With OD-off, the TC locks up at about 38 mph.
Towing with TC locked up reduces heat in the transmission.
Keeping RPM up increases fan speed and coolant flow.

I guess it really all depends on how steep a hill.

I never been to Davis Dam so I have no idea what that's like.
I guess I was thinking about something more familiar, like the
mountains of Tennessee.

mass-hole · **Posted:** Fri Jul 18, 2014 4:05 pm

flash7210 wrote:

mass-hole wrote:

flash7210 wrote:

Towing 5000 lbs, up a hill, in Arizona, in the summer, would be the ultimate test.

I think under those conditions it would be best to have the mechanical fan with hayden
clutch. Keeping vehicle speed at about 58mph in 4th gear, engine at 1900- 2000 rpm to
keep the fan speed up.

If the engine is spinning that slow, wouldnt the electric fan be more useful since you could run it at max regardless of engine speed?

I suppose your right.
The point is that you should not be charging up the hill at 65mph in 5th gear.
You should slow down and stay in a lower gear.
With OD-off, the TC locks up at about 38 mph.
Towing with TC locked up reduces heat in the transmission.
Keeping RPM up increases fan speed and coolant flow.

I guess it really all depends on how steep a hill.

I never been to Davis Dam so I have no idea what that's like.
I guess I was thinking about something more familiar, like the
mountains of Tennessee.

I think there are some videos on Youtube of a guy testing diesel trucks up that pass. They basically just mat the throttle with a 15000 lbs trailer and only let up if they do manage to hit the speed limit.

He doesnt just test diesels either. He did a 1/2 ton episode and the Ford Ecoboost put a pretty good beating on the 6.2L chevy and Tundra.

EDIT: NVM they do the videos on the approach up to the Eisenhower tunnel on I-70

thermorex · **Posted:** Fri Jul 18, 2014 6:01 pm

There are several articles I believe, about that test. Just read one with 10 pages and some videos around, with graphs in MpH average, time to get up to the dam, mileage, etc. That article was from 2011, pretty much the 6 cyl Cummins high output was smoked by both powerstroke and duramax... I think Eisenhower tunnel is a continuation from the dam. Interesting article.

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

Eisenhower tunnel pass and Loveland pass are next to each other. This test can be even more difficult than Davis Dam depending on the vehicle. It starts at about 7000ft and goes to about 10,000ft. The lower oxygen in content in the air is a killer on engine power and heat rejection. All the OEMs use this test site as well.

In most cases the ambient temp may only be 70 F, but the engine will still peak out on coolant temp from the grade load and lower oxygen.

We will be going through this area with a Ram 1500 eco diesel near the end of August along with a 6000-7000lb trailer load. Should be interesting to see how it fairs.

omaharacer · **Posted:** Sat Jul 26, 2014 3:59 pm

1 Week update - If you haven't read up to this point - Front "pusher" A/C Condenser fan is removed for shorting out internally and pulling too many amps. Those factory wires were used, without anything else, and attached to the FFD fan "kit". A/C and 205*F turn on relays work as normal.

So far, under normal driving, everything is working great. Appears as though it has a little more power (seat of the pants), although that is difficult to tell as I could be biased from spending so much on it

A/C still blows nice and cold. Yesterday we had 93*F high "official" w/ heat index around 100*F. EVIC temp, which is reasonably accurate showed 98*. At idle the A/C would blow "cool" but was definitely not cold. This so far, under normal driving conditions, is the only drawback to this modification I've seen. When temps were below 90* the A/C still blew cold. I haven't towed with this, and probably won't tow anything heavy since I have a 6.0 F350 for that. I'll post another update in a few more weeks.

Does anyone know how many CFMs the V6 electric fan puts out? The connector looks the same. I'm assuming less than the FFD fan, but it would be significantly cheaper.

thermorex · **Posted:** Sat Jul 26, 2014 8:32 pm

Great, I haven't had any issues while towing about 2000lbs, but that's nothing to crd. It's good you update about using the he stock wiring, some folks may want to just buy the fan. But I'm a firm believer that the variable speed controller is a very good investment, it won't suck too much power out of the blue. Also, the variable speed controller allows Ac connection, so the fan can be started with it automatically. It really protects the alternator from spike amp draw/sudden power surges... A mater of choice, but I'm as much as possible a perfectionist and 105 bucks ain't too much to do it "right".
Sorry, I have no clue about the v6 e-fan, Keith may know and may post something about it, it seems he's lurking at this thread every know and then...

kidjedi · **Posted:** Mon Aug 01, 2016 4:00 pm

FWIW, I just towed 6,000 pounds (2,210# uhaul transport with an '05 CRD on it) 440 miles with a stock '06 CRD (actually, I do have a Hayden HD fan clutch) from central Wyoming to Denver (plenty of long-hauls up hills). The slowest I had to go was 55mph up hill in pretty decent headwinds, and on the flats I was often cruising around 70-75mph. The outside temp was anywhere from 70 (during the insane hail storms in Cheyenne) to 98. I was using a Bluetooth OBDII and the Torque Pro app to monitor coolant temps and was keeping things around 207 degrees with the A/C on but turning it off going up hill. The coolant temp only spiked a few times going up hill, but it never got over 218 or so.

I was towing the '05 CRD because I broke a rocker a month ago towing a gutted Airstream uphill in 50-80mph winds with 110 degree outside temperatures on one of the hottest days on record for Wyoming in a place that looked like the surface of the moon. I have to admit that at that point I was trusting WAY too much in the dash cluster coolant temp. gauge. It is completely worthless, and the warning signal from the coolant temp comes way... too... late. I assumed it was more like our VW Passat warning, which sounds when the temp is anywhere outside of the safe zone. Evidently the Jeep coolant temp. warning only signals if you're about to be screwed. Anywho...

I actually did the trip again a couple weeks ago with a different CRD retrieving the empty Airstream (which I estimate is around 1500# right now, without the furniture and appliances). The OBD wasn't working too well in that Jeep, so we had to rely on the (horrible) stock coolant temp gauge, but we also had a pyrometer to monitor the exhaust temp. (the probe is mounted in the exhaust manifold before the turbo). The CRD did fine keeping temps down, and the brakes were actually sticking like crazy on that Jeep, so technically we were "pulling" a lot more weight. I was surprised at how well it did anyway. Exhaust temps were around 900 (often less) and would climb to 1000 going up hill, but rarely exceeded 1100 and only a few times hit 1200. Once the brakes were fixed, the owner said the exhaust temp dropped another 250 degrees, so theoretically subtract 250 from the temps above for a properly functioning vehicle. :wink:

For the record, that Jeep does have a deeper transmission pan.

I am planning on purchasing Jeff Bauer's thermostat housing which allows a lot more coolant flow. I am interested to see how it will affect the coolant temp. while towing.

I am looking at everything I can do to keep temps down towing in the summer heat on Colorado/Wyoming/Montana/etc. mountain roads. I was looking at the electric fan option, but I'm not sure it will make that much of a difference. It is interesting to note, however, that there were a few times that my coolant temp actually dropped when I turned the a/c on in the flats. I assume this had to do with the intermittent a/c fan that gave a little extra cooling when the a/c was first turned on. Obviously after a few minutes having the a/c on, the temp would rise quite a bit, but it was making me wonder if an additional fan that you could manually turn on and leave on could help.

I am also considering an auxiliary transmission cooler like Eurekaboy installed, as well as a deeper transmission pan on one of our CRD's (the one that doesn't go off road much, since you can't use the deeper pans with the center/transmission pan skid plate and I'd have to either remove the skid plate or use offsets and lose a decent amount of clearance).

Anyway, I was pretty surprised by how a mostly stock CRD could tow 6,000 pounds in the summer heat as long as I was watching my speed and temps.

mass-hole · **Posted:** Mon Aug 01, 2016 8:17 pm

kidjedi wrote:

FWIW, I just towed 6,000 pounds (2,210# uhaul transport with an '05 CRD on it) 440 miles with a stock '06 CRD (actually, I do have a Hayden HD fan clutch) from central Wyoming to Denver (plenty of long-hauls up hills). The slowest I had to go was 55mph up hill in pretty decent headwinds, and on the flats I was often cruising around 70-75mph. The outside temp was anywhere from 70 (during the insane hail storms in Cheyenne) to 98. I was using a Bluetooth OBDII and the Torque Pro app to monitor coolant temps and was keeping things around 207 degrees with the A/C on but turning it off going up hill. The coolant temp only spiked a few times going up hill, but it never got over 218 or so.

I was towing the '05 CRD because I broke a rocker a month ago towing a gutted Airstream uphill in 50-80mph winds with 110 degree outside temperatures on one of the hottest days on record for Wyoming in a place that looked like the surface of the moon. I have to admit that at that point I was trusting WAY too much in the dash cluster coolant temp. gauge. It is completely worthless, and the warning signal from the coolant temp comes way... too... late. I assumed it was more like our VW Passat warning, which sounds when the temp is anywhere outside of the safe zone. Evidently the Jeep coolant temp. warning only signals if you're about to be screwed. Anywho...

I actually did the trip again a couple weeks ago with a different CRD retrieving the empty Airstream (which I estimate is around 1500# right now, without the furniture and appliances). The OBD wasn't working too well in that Jeep, so we had to rely on the (horrible) stock coolant temp gauge, but we also had a pyrometer to monitor the exhaust temp. (the probe is mounted in the exhaust manifold before the turbo). The CRD did fine keeping temps down, and the brakes were actually sticking like crazy on that Jeep, so technically we were "pulling" a lot more weight. I was surprised at how well it did anyway. Exhaust temps were around 900 (often less) and would climb to 1000 going up hill, but rarely exceeded 1100 and only a few times hit 1200. Once the brakes were fixed, the owner said the exhaust temp dropped another 250 degrees, so theoretically subtract 250 from the temps above for a properly functioning vehicle. :wink:

For the record, that Jeep does have a deeper transmission pan.

I am planning on purchasing Jeff Bauer's thermostat housing which allows a lot more coolant flow. I am interested to see how it will affect the coolant temp. while towing.

I am looking at everything I can do to keep temps down towing in the summer heat on Colorado/Wyoming/Montana/etc. mountain roads. I was looking at the electric fan option, but I'm not sure it will make that much of a difference. It is interesting to note, however, that there were a few times that my coolant temp actually dropped when I turned the a/c on in the flats. I assume this had to do with the intermittent a/c fan that gave a little extra cooling when the a/c was first turned on. Obviously after a few minutes having the a/c on, the temp would rise quite a bit, but it was making me wonder if an additional fan that you could manually turn on and leave on could help.

I am also considering an auxiliary transmission cooler like Eurekaboy installed, as well as a deeper transmission pan on one of our CRD's (the one that doesn't go off road much, since you can't use the deeper pans with the center/transmission pan skid plate and I'd have to either remove the skid plate or use offsets and lose a decent amount of clearance).

Anyway, I was pretty surprised by how a mostly stock CRD could tow 6,000 pounds in the summer heat as long as I was watching my speed and temps.

My temps have been creeping on big climbs here in Utah unloaded. I've never seen this before but I also haven't really lived out here all that long. 100+ degrees, 6500' and a bad fan clutch are too much I guess. I am trying to decide between replacing the clutch with a hayden or converting to electric.

I have notice a pretty big difference with a/c on and off. Certainly it affects coolant temps but I've seen a bigger difference in the IAT's.

Also, based on the maps I have seen in our tunes, boost will start to be cut at something like 50C IAT's and above and fuelling will begin to be cut around 107C. If you run the 4J housing with a 95c tstat it doesn't leave you a lot of room before this happens.

Sent from my Nexus 6 using Tapatalk

flash7210 · **Posted:** Mon Aug 01, 2016 8:50 pm

Quote:

and fuelling will begin to be cut around 107C

This is coolant temp, not IAT. 220 deg F.

Icecrd1669 · **Joined:** Tue Aug 16, 2016 11:05 pm **Posts:** 8

I tried the electric set up from FFD. The relay temp switch they include failed within the first two months. Prepare for a proper fan controller.
I was also running an ARB bumper with a winch. There is not enough airflow provided by this fan and set up to prevent overheating. Switched back to a stock mechanical fan and Jeffs HDS thermostat. Not a waiver in the temp gauge on some hot days, a full on cruise speed and tow day.

mass-hole · **Posted:** Fri Aug 19, 2016 12:48 pm

Icecrd1669 wrote:

I tried the electric set up from FFD. The relay temp switch they include failed within the first two months. Prepare for a proper fan controller.
I was also running an ARB bumper with a winch. There is not enough airflow provided by this fan and set up to prevent overheating. Switched back to a stock mechanical fan and Jeffs HDS thermostat. Not a waiver in the temp gauge on some hot days, a full on cruise speed and tow day.

This is the first time I have seen someone say the FFD didnt do the job. What temp was it turning on at?

One thing you may wanna try is pulling the AC fan and using the AC fan wiring to run the FFD. The A/C fan is set to come on at 96.5C coolant temps, so just slightly above the HDS tstat temp. This will open up the front of the grill for some better flow and it will allow the FFD to run double duty as both the cooling and A/C fan. Obviously you would wanna make sure the existing Relays and fuses are enough to handle the job since the FFD is a beast.

The other thing I was thinking, Using two of the FFD14 fans instead of just one FFD3600(16") would give you a lot more flow and could fit on the 20x20" radiator shroud. 2 14's would give you 5200 CFM vs 3600 CFM of the 16"

The last option, which I am going to try first, is using a taurus SHO or 1998-2000 Volvo S70/V70 fan. The Volvo fan is the same motor as the taurus fan which is apparently a beast, but I believe the blade design is a bit different. I picked up a Volvo fan from the local Pick-n-Pull the other day for $25. I am going to try this setup on the A/C fan wiring and see if it does the job, otherwise i will step up to dual FFD14's. I dont know if 2 volvo fans will fit our radiators, I think the shroud around the fan is close to 16".

peteyz24 · **Posted:** Fri Aug 19, 2016 1:14 pm

I am thinking I may try and find a sho fan. From what I read they are suppose to move 5000 cfm

69Hcode · **Posted:** Fri Aug 19, 2016 3:16 pm

I've had two 1998 SHO fans in my 2004 expedition for over a year now. Only problem was the cheap controller I tried to use. I got one from Dakota digital and it's been great. Fully programmable.

My A/C is always cold and it always keeps the engine cool. I added led lights so I know when the fans turn on.

jrsavoie · **Posted:** Fri Sep 09, 2016 9:06 am

mass-hole wrote:

Icecrd1669 wrote:

I tried the electric set up from FFD. The relay temp switch they include failed within the first two months. Prepare for a proper fan controller.
I was also running an ARB bumper with a winch. There is not enough airflow provided by this fan and set up to prevent overheating. Switched back to a stock mechanical fan and Jeffs HDS thermostat. Not a waiver in the temp gauge on some hot days, a full on cruise speed and tow day.

This is the first time I have seen someone say the FFD didnt do the job. What temp was it turning on at?

One thing you may wanna try is pulling the AC fan and using the AC fan wiring to run the FFD. The A/C fan is set to come on at 96.5C coolant temps, so just slightly above the HDS tstat temp. This will open up the front of the grill for some better flow and it will allow the FFD to run double duty as both the cooling and A/C fan. Obviously you would wanna make sure the existing Relays and fuses are enough to handle the job since the FFD is a beast.

The other thing I was thinking, Using two of the FFD14 fans instead of just one FFD3600(16") would give you a lot more flow and could fit on the 20x20" radiator shroud. 2 14's would give you 5200 CFM vs 3600 CFM of the 16"

The last option, which I am going to try first, is using a taurus SHO or 1998-2000 Volvo S70/V70 fan. The Volvo fan is the same motor as the taurus fan which is apparently a beast, but I believe the blade design is a bit different. I picked up a Volvo fan from the local Pick-n-Pull the other day for $25. I am going to try this setup on the A/C fan wiring and see if it does the job, otherwise i will step up to dual FFD14's. I dont know if 2 volvo fans will fit our radiators, I think the shroud around the fan is close to 16".

I heard if you get the Volvo fan to get the complete harness with it. It's supposed to be pretty much plug and play. From what I gathered the sensor will fit in Jeff's thermostat for a complete unit

On a previous post someplace it was stated 92 - 97 Volvo fan. Something was said about a station wagon. I've been looking for the post

thermorex · **Posted:** Fri Sep 09, 2016 8:54 pm

mass-hole wrote:

Also, based on the maps I have seen in our tunes, boost will start to be cut at something like 50C IAT's and above and fuelling will begin to be cut around 107C. If you run the 4J housing with a 95c tstat it doesn't leave you a lot of room before this happens.

Sent from my Nexus 6 using Tapatalk

Why do you think I swapped the 205F stant from hds with an 190F stant? Lol. A bit of offroad experience. In oh and pa area, which is not near Davis dam difficulty, I can't overheat the engine no matter what I do. On or off road. Before hds I would have gone towards few tics toward 3/4 gauge. Btw, what obd2 gauge/Bt receiver you use. I wasn't able to get anything that doesn't freeze the gauge or torque pro...

thermorex · **Posted:** Fri Sep 09, 2016 8:57 pm

mass-hole wrote:

Icecrd1669 wrote:

I tried the electric set up from FFD. The relay temp switch they include failed within the first two months. Prepare for a proper fan controller.
I was also running an ARB bumper with a winch. There is not enough airflow provided by this fan and set up to prevent overheating. Switched back to a stock mechanical fan and Jeffs HDS thermostat. Not a waiver in the temp gauge on some hot days, a full on cruise speed and tow day.

This is the first time I have seen someone say the FFD didnt do the job. What temp was it turning on at?

One thing you may wanna try is pulling the AC fan and using the AC fan wiring to run the FFD. The A/C fan is set to come on at 96.5C coolant temps, so just slightly above the HDS tstat temp. This will open up the front of the grill for some better flow and it will allow the FFD to run double duty as both the cooling and A/C fan. Obviously you would wanna make sure the existing Relays and fuses are enough to handle the job since the FFD is a beast.

The other thing I was thinking, Using two of the FFD14 fans instead of just one FFD3600(16") would give you a lot more flow and could fit on the 20x20" radiator shroud. 2 14's would give you 5200 CFM vs 3600 CFM of the 16"

The last option, which I am going to try first, is using a taurus SHO or 1998-2000 Volvo S70/V70 fan. The Volvo fan is the same motor as the taurus fan which is apparently a beast, but I believe the blade design is a bit different. I picked up a Volvo fan from the local Pick-n-Pull the other day for $25. I am going to try this setup on the A/C fan wiring and see if it does the job, otherwise i will step up to dual FFD14's. I dont know if 2 volvo fans will fit our radiators, I think the shroud around the fan is close to 16".

Me neither, haven't heard anybody complaining about ffd fan... Lecrd may be doing some extreme driving/towing... Listening to Keith, looks like the most efficient fan is the stock mechanical fan. I wonder, after some mods to the bracket that holds the hood latch, how efficient the cooling would be with 2x 12inch ffd fans installed as pushers... This is my next summer project for the EcoDiesel.

jrsavoie · **Posted:** Sat Sep 10, 2016 6:48 am

jrsavoie wrote:

mass-hole wrote:

Icecrd1669 wrote:

I tried the electric set up from FFD. The relay temp switch they include failed within the first two months. Prepare for a proper fan controller.
I was also running an ARB bumper with a winch. There is not enough airflow provided by this fan and set up to prevent overheating. Switched back to a stock mechanical fan and Jeffs HDS thermostat. Not a waiver in the temp gauge on some hot days, a full on cruise speed and tow day.

This is the first time I have seen someone say the FFD didnt do the job. What temp was it turning on at?

One thing you may wanna try is pulling the AC fan and using the AC fan wiring to run the FFD. The A/C fan is set to come on at 96.5C coolant temps, so just slightly above the HDS tstat temp. This will open up the front of the grill for some better flow and it will allow the FFD to run double duty as both the cooling and A/C fan. Obviously you would wanna make sure the existing Relays and fuses are enough to handle the job since the FFD is a beast.

The other thing I was thinking, Using two of the FFD14 fans instead of just one FFD3600(16") would give you a lot more flow and could fit on the 20x20" radiator shroud. 2 14's would give you 5200 CFM vs 3600 CFM of the 16"

The last option, which I am going to try first, is using a taurus SHO or 1998-2000 Volvo S70/V70 fan. The Volvo fan is the same motor as the taurus fan which is apparently a beast, but I believe the blade design is a bit different. I picked up a Volvo fan from the local Pick-n-Pull the other day for $25. I am going to try this setup on the A/C fan wiring and see if it does the job, otherwise i will step up to dual FFD14's. I dont know if 2 volvo fans will fit our radiators, I think the shroud around the fan is close to 16".

I heard if you get the Volvo fan to get the complete harness with it. It's supposed to be pretty much plug and play. From what I gathered the sensor will fit in Jeff's thermostat for a complete unit

On a previous post someplace it was stated 92 - 97 Volvo fan. Something was said about a station wagon. I've been looking for the post

Will the Volvo fan fit between the radiator and our engine?

Electric vs Mechanical fan cfm

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