Let’s talk transmission temps

[03_GMC]

I really really really don't like to argue with anyone on the internet.. I'm too old...
But I want people to know the facts>>>>>
Your electric engine cooling fans will NOT be commanded to turn on NO MATTER what
the coolant temp is at highway speeds...
Maybe you have a custom tune that does command them to ON at 60mph,
but it really wouldn't have any benefit due to the incoming air at speed anyway.
This is the reason the OEMS do not do it.
IF yours turn on at 60mph, then you have the unicorn... I do understand the differences in mechanical, electrical, viscous types of fans that the oems have used
for over 100 years

I do not have any "swap" crap in my rig. It's the factory engine, trans, diffs, etc/
I do have a supercharger and a tune of course.
My fans are programmed to come on low speed at 202* and high speed at 212* ..
I can watch my duty % at all times so I know exactly when the fans operate.
But as stated, oem electric fans don't come on at 60mph..Now, if you slow down then
they do come on and will run on high if temp demands it. But keeping cool at a steady
60-70 mph while towing on grades in 90*+ weather presents a whole different set
of parameters

Hey Foggy I’m not trying to argue either. I also wasn’t implying you had a crappy swap. Hearing that you had an intercooler and were doing a meth injection setup from snow performance naturally makes most people assume you have a diesel. So I am sorry if that assumption upset you that wasn’t my intention. I understand the logic behind going at highway speeds and that air is naturally moving through the radiators at a higher speed than when on the side roads at 30-40mph. However the engineers have designed these fans to move air at a faster rate when set to a 97% duty cycle than the air is moving going highway speeds with no fan helping to pull the air through. GM doesn’t allow the fans to go to 97% duty cycle until your coolant is over 225. Whether you are on the interstate or not. Once you hit that coolant temp the fans then run at max and can finally help cool the engine down. The factory ECU cooling fan duty cycles are set by coolant temp not speed. I watched the tuner change it in HPTuners. Again not trying to argue with you as you seem very smart and knowledgeable. I am just sharing what I have seen with my own eyes and know from asking many questions during the tuning process. A replacement ext tranny cooler is a must. The factory one is junk. However the tune also helps keep your vehicle from getting as hot as quickly as it does with the factory parameters. I think both are a great upgrade and a must when towing with these trucks.


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[03_GMC]

I really really really don't like to argue with anyone on the internet.. I'm too old...
But I want people to know the facts>>>>>
Your electric engine cooling fans will NOT be commanded to turn on NO MATTER what
the coolant temp is at highway speeds...
Maybe you have a custom tune that does command them to ON at 60mph,
but it really wouldn't have any benefit due to the incoming air at speed anyway.
This is the reason the OEMS do not do it.
IF yours turn on at 60mph, then you have the unicorn... I do understand the differences in mechanical, electrical, viscous types of fans that the oems have used
for over 100 years

I do not have any "swap" crap in my rig. It's the factory engine, trans, diffs, etc/
I do have a supercharger and a tune of course.
My fans are programmed to come on low speed at 202* and high speed at 212* ..
I can watch my duty % at all times so I know exactly when the fans operate.
But as stated, oem electric fans don't come on at 60mph..Now, if you slow down then
they do come on and will run on high if temp demands it. But keeping cool at a steady
60-70 mph while towing on grades in 90*+ weather presents a whole different set
of parameters

Hey Foggy I’m not trying to argue either. I also wasn’t implying you had a crappy swap. Hearing that you had an intercooler and were doing a meth injection setup from snow performance naturally makes most people assume you have a diesel. So I am sorry if that assumption upset you that wasn’t my intention. I understand the logic behind going at highway speeds and that air is naturally moving through the radiators at a higher speed than when on the side roads at 30-40mph. However the engineers have designed these fans to move air at a faster rate when set to a 97% duty cycle than the air is moving going highway speeds with no fan helping to pull the air through. GM doesn’t allow the fans to go to 97% duty cycle until your coolant is over 225. Whether you are on the interstate or not. Once you hit that coolant temp the fans then run at max and can finally help cool the engine down. The factory ECU cooling fan duty cycles are set by coolant temp not speed. I watched the tuner change it in HPTuners. Again not trying to argue with you as you seem very smart and knowledgeable. I am just sharing what I have seen with my own eyes and know from asking many questions during the tuning process. A replacement ext tranny cooler is a must. The factory one is junk. However the tune also helps keep your vehicle from getting as hot as quickly as it does with the factory parameters. I think both are a great upgrade and a must when towing with these trucks.


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[Rocket Man]

The only way the fans will be on at highway speeds is if you’ve done some crazy programming in the tune which is pointless because your electric fans will actually be hindering airflow at that point. The factory tune turns them off at a certain speed, not sure but I believe it’s 40-45 and they free spin at that point. This also conserves fuel since you don’t need the alternator loaded with 50 amps of draw or whatever they pull. I know it’s a lot. I’m with with @Foggy on this. I don’t know what tuner told you the fans run at highway speed. I know mine don’t.

 

[Rocket Man]

Also, an intercooler is standard with a blower like I also have, and meth injection is used on gas just as much as diesel. I have considered it on mine. So most people -especially here- here don’t assume it’s a diesel when talking about these.

 

[03_GMC]

Also, an intercooler is standard with a blower like I also have, and meth injection is used on gas just as much as diesel. I have considered it on mine. So most people -especially here- here don’t assume it’s a diesel when talking about these.

I honestly didn’t even think about a blower until he said something. But I definitely know that it’s wise to run one. Once the coolant temp hits a certain degrees your fans will kick on. If you’ve ever gotten hot going down the interstate you’ll hear the fans run at full speed. That’s when my temps would finally start coming down. I don’t disagree that they may shut off but if your coolant temp gets to the point of needing the full duty cycle of the fan then they will turn on no matter the speed.


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[Rocket Man]

I disagree. And I’ll leave it at that. BTW most of the blower kits out there include an intercooler as part of the package. My Whipple did.
Edit: I stand corrected. After I looked into it, it seems the fans may indeed turn on in an overheat event on the freeway. This will now require me to look into this further. I have never experienced this though.

 

[03_GMC]

I disagree. And I’ll leave it at that. BTW most of the blower kits out there include an intercooler as part of the package. My Whipple did.
Edit: I stand corrected. After I looked into it, it seems the fans may indeed turn on in an overheat event on the freeway. This will now require me to look into this further. I have never experienced this though.

All good man. Just like you I am here to help out. I saw and experienced an issue and was able to get a part of a solution and wanted to share.


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[Geotrash]

This confirms what I experienced as well. As I was approaching the peak temps during a few hill climbs, I could feel something electrical engage, and the coolant temp would come down 10º-15º on its own, while still running hard in the climb.

 

[Foggy]

I'll get a couple of pics of the install in next day or two with the derale
installed behind the front bumper

 

[03_GMC]

I'll get a couple of pics of the install in next day or two with the derale
installed behind the front bumper

Awesome man. Looking forward to seeing it!


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