Horton Fan Vs HP Gains

[Archive]

Installed my Horton Fan then ran the truck across the dyno first with fan disengaged, then engaged. Here's what I got. I gained 21hp at 60mph; 13hp at 50mph; and 7hp at 40mph. My back end is the 3. 54 ratio and I've got an automatic transmission. Hope this sheds a little light on some of the speculation about any hp gains or losses with the fan.

[This message has been edited by Banshe (edited 10-21-2000). ]

 

[Archive]

Did you try it first with the stock fan cold? The stock fan cold runs almost free. It has a clutch sorta like a torque converter. When the little spring on the front gets hot enough it closes a valve and gradually engages the fan. Try spinning the fan a few turns by hand when cold (engine off I hope) and you will feel it free up after a few turns. This is how it runs until hot. It is really quite an amazing devise and works quite well. I would really like to see some dyno numbers on this.

I'm not so sure the Horton has it that much over the stock fan. Your figures sure show how much the fan can require though.
Larry

------------------
1972 Chinook class C with 96/215 5spd, 4/5" exh, 4"BD, MagHytec, 85gal fuel, K&N, AutoMeter, www.fostertruck.com/cummins

 

[Archive]

LarryB

When I made this Dyno run, I had also installed a BD Governor Spring kit, so the power band shifted up on me. I didn't think about it until after the run, but my previous runs cannot be directly compared until I can find where my peak hp/torque is now at. I've sent a message to Piers hoping he can tell me roughly where the band peaks are now. I had read several threads where the fan sucks up 20-25 hp and this run seems to confirm that. I had understood that the stock fan clutch never fully "free wheels" and it never fully "engages". Since the Horton does 100% engagement, I would suspect that it sucks more hp than the stock which engages at 80% of engine rpm.

Since the Horton can be manually switched on, I'm hoping that I can precool the system just prior to hauling my 5er over a mountain top. Also since it kicks in at 100%, I'm hoping that it will provide extra cooling during a hard pull. I'm not really after the hp gains or the "quicker" warm ups, if that's even valid.

 

[Archive]

Sounds like a good plan to me. I would love to have one but the're a bit spendy for me.
Have fun!

 

[Archive]

Banshe, in addition, the Horton moves CONSIDERABLY MORE air #ad
than the OE fan (i. e. , much more parasitic drag WHILE engaged), further skewing your comparison results. I would be surprised if the OE fan in its more or less freewheel state uses more than 5 HP.

 

[Archive]

John, I went back and read an article in TDR #24 and here's what we've got. "In theory, the OEM fan uses . 67hp at 1000rpm and 14hp at 2750rpm and as much as 26hp at 3600rpm. " Now, because the Horton engages at 100% and it has a higher capacity designed blade, I would expect the Horton takes more hp when engaged than does the OEM. The closest test I have is at 2800 rpms the Horton is sucking 21hp compared to just over 14hp for the OEM. Something else not figured in is that the OEM is 80% engaged at 190 degrees. The Horton doesn't engage until 200 degrees. What I'm seeing is that the cooling system typically doesn't get to 200 degrees. Once the thermostat opens, the radiator has the capacity to cool the system down without the Horton fan engaging. I've only been running the Horton for a couple weeks, and in that time the fan has kicked in maybe 3 or 4 times. The ambient temps have been any where from a low of 38 to a high of 72 and I typically put 35 to 50 miles on it every day. The only benefit I'm really interested in is that it provides more cooling than the OEM. That's probably a good thing, because I'm not so sure that any hp gains aren't offset by the increase in hp required to drive the Horton. I'm headed out over the Rockies this week so I'll see what it does for additional cooling when under a load. I'll be dragging a 5er at 12K to 13K lbs.

Thanx
"Banshe" Bill

------------------
'95, 2500, 4X4, ext cab, 12 valve, auto transmission, 3. 54 back end, white, Banks Power Pak, Kondolay TC, Kondolay VB, Bully Dog Propane, 16cm housing, 4" exhaust, Horton Fan, Bosch 215, BD Governor Springs, Brite Box, Wiley Coyote strapped to my grill
Parts on order are Griffin Radiator, Leather Interior, Wood Dash Kit

[This message has been edited by Banshe (edited 10-23-2000). ]

 

[Archive]

I'm not all that familar with the Horton,just wondering about the mechcanics of turning it on manually,is it radio controled or is there a part that doesn't spin?

 

[Archive]

Banshe, I'm familiar with most (if not all) of the TDR articles pertaining to the Horton fan clutch however, I believe the HP figures were measured with the OE fan clutch engaged. With the OE fan in the "freewheel" mode I would seriously doubt drag could amount to more than I what stated in my last post. Remember, those figures were measured by Horton (see letter by Horton in the same issue). Additionally, the best mpg increase I've seen associated with the addition of the Horton is 2. 02... and almost every other Horton owner has reported a negligible fuel increase. Then there's the reliability issues several Rammers have experienced (other than Andy)... .

Is the OE fan really that bad? How could any replacement fan be more reliable? Do the benifits of the Horton outweigh the $700. price of admission? Let's hear what some of the Horton owners have to say.

 

[Archive]

I think I read that, with the Horton, another consideration is geography: Where do you live/drive most of the time?

From what I've heard, the Horton is more of a liability than an asset if you live in very warm areas like the gulf coast or southeast, where temperatures in the spring/summer/fall will keep ANY FAN running (with AC on) most of the time.

I agree with an earlier poster about "the price of admission," too. You'll never recoup your investment unless the fuel savings can be demonstrated to be fairly substantial --- even at $1. 65/gal for fuel --- fugedaboutit!

------------------
97 2500 4x4, club cab, auto, 3. 54 limited slip, JRE 4" exhaust, Dr. Performance Fuel system (370 HP), "Twister Turbo," Geno's guages -- Boost, EGT, transmission & Rear -- MAG Hytec covers, SunCoast Converter/Transgo shift kit, Brite Box, tons o'chrome under hood, Prime Loc, EZ Drain, Seat covers, wood dash, Rancho Suspension, Warn M12000 Winch on Warn Brush Guard, Warn driving and fog lights, Hella twin back up lights, 285/75/R16 B. F. G. ATs on Mickey Thompson "Classic" rims; Linex bed liner, BD exhaust brake, Optima, "Red-top" batteries. Northwest Custom mudflaps, front/rear, and stainless rocker panels.

 

[Archive]

Another consideration I've always wondered about with the Horton... since the fan does NOT run most of the time, it would seem to me you would lose some intercooler efficiency because the fan is not helping the air move through the A/C condenser/intercooler/radiator via a drawing effect. I realize at highway speeds this would be a moot point however, I would suspect there would be some loss at moderate speeds. Does anyone have an opinion on this? Just curious.

[This message has been edited by John (edited 10-24-2000). ]

 

[Archive]

Sasquatch,
I agree about the return on investment if your counting on gas mileage to make it up. Since I live in the Rockies, the temps here are pretty cool so the fan doesn't engage hardly at all.

John,
If at 1000 rpm the OEM clutch only uses . 67hp, assuming that the aricle was with the clutch engaged, then I agree that the OEM clutch wouldn't use any appreciable horsepower at all when it's disengaged. Since you asked the question about the intercooler, it does relate to an issue I've been experiencing for the past two weeks. I've noticed that my EGTs are typically 150 degrees higher than normal when at slow speeds. They even climb when setting at idle to about 450-500 degrees. Tomorrow I'll leave the fan on and see what it does for the EGTs. I had originally thought maybe it was caused by one of the bombing upgrades I put in it over the past two weeks (injectors, spring kit, turbo, propane). Will post the results when I get home from work. I hadn't read anything about this being an issue with the fan, but we'll see. That would sure explain what I'm seeing. If the fan can keep my system cool while towing over the mountain passes, then it's worth it. The OEM setup can't handle it and allows the transmission to overtemp. I have to pull over half way up the pass, or slow down to about 25-30 and run it with the water temp on the "red line".

[This message has been edited by Banshe (edited 10-24-2000). ]

 

[Archive]

Whoa Banshe! I wouldn't leave the Horton fan on for any extended length of time... ... with the amount of air that thing moves (read: wind tunnel), you may ice up your intercooler! #ad
#ad
#ad
#ad

 

[Archive]

I'm in San Diego now and hauled my 5er out of Colorado, over Raton, down through Tucson and then to here. LOVE that Horton fan!!!! #ad
#ad
#ad
#ad
Last time I came this way, I almost had to pullover near Pine Valley. Temp went up to the red #ad
, but didn't boil over and didn't get the trans temp light until after topping the climb, so kept on truckin'. It's a near constant climb for several miles. There are water barrels along the highway about every 1/4 mile. I saw at least a half dozen folks pulled over on each trip. On this trip, I turned the fan on before the climb, and the temp only made it up to 190 one time, but soon as the thermostat opened wide, she cooled right back down to about 160. The trans temp only got to 170 degrees. If you're concerned about the extra heat generated from a heavy tow, then the Horton may be worth the investment. It is well worth it to me. Now I know I can tow when I want, where I want and not be concerned about overheating either my engine or the transmission. Of course if I'd bought a manual transmission, I probably wouldn't have to worry about over heating either #ad
.