Keeping coolant and transmission temps under control when towing in the summer heat

[Geotrash]

Thru my Diablosport, I have noticed that the fans don't really come on
the low setting until about 44% fan command..
The fans aren't really "variable speed", just Low or High Speed

I have to "get into" my HP Tuners and learn it so I can turn the
Fan Command % numbers UP at highway speeds.
They don't really go over 25% even at 210* at speed.. At low speeds,
they start on low speed at 202* and will go up to 90% with AC on
or if temp goes over 212*.
Kinda dumb system IMO.. Why not just OFF/LOW/HIGH like many
of my other "fan command states"

Very helpful observations - thanks for sharing them. I'm wondering if maybe they set them that way to prolong the life of the fan motors, or if maybe other fan speeds become available under different combinations of factors.

I've noticed that while my coolant temp will get up as high as 230ºF on a hot day towing on the interstate, that it stays cool (below 215ºF) when climbing a long 7+% grade, even though I'm only doing maybe 35 by the time I reach the top. This, while my transmission temps climb through the roof. Makes me wonder if the fan speed will increase as vehicle speed decreases to compensate for loss of ram air.

 

[Geotrash]

Relocated the license plate last night and drilled out the holes for better ram air to the Derale. I used 4" long machine screws with washers and locking nuts, and cut some 3.5" long pieces of pex pipe to serve as standoffs to keep the plate rigid. I sometimes use an automatic carwash, and don't want the spinning brushes pulling the plate off if I can help it.

 

[gooffeyguy]

Relocated the license plate last night and drilled out the holes for better ram air to the Derale. I used 4" long machine screws with washers and locking nuts, and cut some 3.5" long pieces of pex pipe to serve as standoffs to keep the plate rigid. I sometimes use an automatic carwash, and don't want the spinning brushes pulling the plate off if I can help it.

View attachment 281422
View attachment 281424

Shit, I'm surprised you didn't do what many people do around here that don't want the look of a front plate or don't want to drill holes in their new aftermarket bumper for it. Lay it on the passenger side dash up in the windshield

 

[HD_LS]

Very helpful observations - thanks for sharing them. I'm wondering if maybe they set them that way to prolong the life of the fan motors, or if maybe other fan speeds become available under different combinations of factors.

I've noticed that while my coolant temp will get up as high as 230ºF on a hot day towing on the interstate, that it stays cool (below 215ºF) when climbing a long 7+% grade, even though I'm only doing maybe 35 by the time I reach the top. This, while my transmission temps climb through the roof. Makes me wonder if the fan speed will increase as vehicle speed decreases to compensate for loss of ram air.

Do you have the AC off on the uphill climbs?

 

[Geotrash]

Do you have the AC off on the uphill climbs?

No, and I'm trying to avoid having to do that unless there is literally no other option. I'm optimistic that with this final mod that I'll be able to keep the temps under control for good, for any of the towing we have planned this year and will plan in the years ahead.

 

[exp500]

For Ya'all that are looking for that extra edge especially towing, this has been good for me and inexpensive.

WaterWetter®

Unique agent for cooling systems that doubles the wetting ability of water

www.redlineoil.com

 

[03_GMC]

Ok for some reason Tapatalk won’t log me in. So how about a first day report?

We went from East of Dallas to North Denver in a day. 14 hrs with stops. Saw a best of 11.5 MPGs. This little trailer is all steel. Frame, panels and inside framing as well. It’s a fairly stout and heavy little guy.

For most of the day trans temps averaged between 176-185. On a few two lane road vehicle passes the temp would climb to 205 and then come back down afterwards. When I arrived in Limon on I70 I stopped to fill up and the temp creeped up to 210. I figured I should probably see if the thermostat was working. I climbed under the Denali and sure enough it wasn’t. Then all of a sudden it came on for about 10 seconds and shut off again. So I grabbed my tools and made a straight connection to the fans positive wire. After that the temp never rose above 185. My coolant temp never budged the entire day so having the tune reprogram the fans is a huge benefit.

Today we pick up the rental camper. A Grand Design Imagine 2400BH. I’ll report back tonight with how our trip from Denver to Rock Springs Wyoming went!

 

[Fless]

FYI Tapatalk is no longer supported in the new version of the forum. See the "What Happened" thread.

 

[Geotrash]

Ok for some reason Tapatalk won’t log me in. So how about a first day report?

We went from East of Dallas to North Denver in a day. 14 hrs with stops. Saw a best of 11.5 MPGs. This little trailer is all steel. Frame, panels and inside framing as well. It’s a fairly stout and heavy little guy.

For most of the day trans temps averaged between 176-185. On a few two lane road vehicle passes the temp would climb to 205 and then come back down afterwards. When I arrived in Limon on I70 I stopped to fill up and the temp creeped up to 210. I figured I should probably see if the thermostat was working. I climbed under the Denali and sure enough it wasn’t. Then all of a sudden it came on for about 10 seconds and shut off again. So I grabbed my tools and made a straight connection to the fans positive wire. After that the temp never rose above 185. My coolant temp never budged the entire day so having the tune reprogram the fans is a huge benefit.

Today we pick up the rental camper. A Grand Design Imagine 2400BH. I’ll report back tonight with how our trip from Denver to Rock Springs Wyoming went!

Fabulous! Thanks for the update + data, and safe travels!

 

[Fless]

Also give us an idea which route you take from North Denver -- I-25 to Cheyenne, 287 to Laramie, or ?