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

[alpha_omega]

Wow if we are only moving 1300cfm total then a cooling fan upgrade may be one of the best upgrades yet. @Geotrash i nominate you to change your before the Yellowstone trip lol

You have remember though, that’s the cfm listed for the motor only. How much more does the fan blade add (whether it’s 5, 7, 9 bladed) is as subjective as the total number, since there are so many factors that go into it. I’m not sure if the 1300cfm total is from the factory with everything assembled or not. It would make sense to see a number like that, because most big aftermarket fans advertising numbers in the 8k-10k range are only that high because they are listing the “full-flow” numbers - no obstructions whatsoever - however, down here in reality-land we have things like radiators, trans coolers, bumpers, baffles and grilles all playing a role in the amount of airflow being moved.

Nonetheless, if I remember correctly I’m pretty sure the number you want to shoot for on a V8 is closer to 2500 (minimum), so if that’s the case then we are asking for trouble by doing any kind of towing in temps above 75* while running stock fan kits. I’m sure glad you guys brought that topic up…now you’ve got me scratching my damn head again.

 

[Geotrash]

You have remember though, that’s the cfm listed for the motor only. How much more does the fan blade add (whether it’s 5, 7, 9 bladed) is as subjective as the total number, since there are so many factors that go into it. I’m not sure if the 1300cfm total is from the factory with everything assembled or not. It would make sense to see a number like that, because most big aftermarket fans advertising numbers in the 8k-10k range are only that high because they are listing the “full-flow” numbers - no obstructions whatsoever - however, down here in reality-land we have things like radiators, trans coolers, bumpers, baffles and grilles all playing a role in the amount of airflow being moved.

Nonetheless, if I remember correctly I’m pretty sure the number you want to shoot for on a V8 is closer to 2500 (minimum), so if that’s the case then we are asking for trouble by doing any kind of towing in temps above 75* while running stock fan kits. I’m sure glad you guys brought that topic up…now you’ve got me scratching my damn head again.

If it helps, the stock fan motors (including towing package, which I have), are 500W each. There is also an even heavier duty cooling package (K5L), which is rare, and apparently mine doesn't have, but it has 700W fan motors. Hence my plan to swap the fan motor and blade on the driver's side with a 700W motor, thanks to @thompsoj22 's comments early on.

 

[gooffeyguy]

If it helps, the stock fan motors (including towing package, which I have), are 500W each. There is also an even heavier duty cooling package (K5L), which is rare, and apparently mine doesn't have, but it has 700W fan motors. Hence my plan to swap the fan motor and blade on the driver's side with a 700W motor, thanks to @thompsoj22 's comments early on.

If it helps, the stock fan motors (including towing package, which I have), are 500W each. There is also an even heavier duty cooling package (K5L), which is rare, and apparently mine doesn't have, but it has 700W fan motors. Hence my plan to swap the fan motor and blade on the driver's side with a 700W motor, thanks to @thompsoj22 's comments early on.

Someone on here replaced their fan motors and blades with the 700w ones then started having electrical issues with the dash gauges or something whenever they would kick on. Think they replaced the alternator with a bigger amp one to fix it.

 

[Geotrash]

Someone on here replaced their fan motors and blades with the 700w ones then started having electrical issues with the dash gauges or something whenever they would kick on. Think they replaced the alternator with a bigger amp one to fix it.

Yup, that was @thompsoj22 on this thread.

 

[mikeyss]

I have the dual 700w setup and have had no electrical issues, but they are loud on high and even on low they can be heard standing in front of the Tahoe. Mine originally came with the 5/7 rimmed 500w, I quickly upgraded them shortly after buying my hoe.

 

[thompsoj22]

I have the dual 700w setup and have had no electrical issues, but they are loud on high and even on low they can be heard standing in front of the Tahoe. Mine originally came with the 5/7 rimmed 500w, I quickly upgraded them shortly after buying my hoe.

Short version? OE 5/7 500 watt, Upgraded to 700 watt motors which can draw up to 55amps when they cycle from low to high, Thats a 110 amp draw and at idle with the alt below it's rated output rpm the fans cycled to high, the lights dimmed and the bose stereo "blanked out" no display and no function. I recovered that anomaly with a bose input code entered by holding your finger in the bottom left corner of the screen. Anyway i decided to go with just one 700 watt 7 blade on the drivers side and staying with the 500/5 blade on the passenger side and i have had no further issues. Twin 700's move massive air but at idle in stop and go traffic they place an extreme burden on the alternator. This is just my experience, I am now running the DENSO 6860 220 amp alternator with overdrive pulley and all the big grounds/feed cables and can sit in stop and go extreme summer heat with ac on max and not have any issues.

 

[alpha_omega]

Short version? OE 5/7 500 watt, Upgraded to 700 watt motors which can draw up to 55amps when they cycle from low to high, Thats a 110 amp draw and at idle with the alt below it's rated output rpm the fans cycled to high, the lights dimmed and the bose stereo "blanked out" no display and no function. I recovered that anomaly with a bose input code entered by holding your finger in the bottom left corner of the screen. Anyway i decided to go with just one 700 watt 7 blade on the drivers side and staying with the 500/5 blade on the passenger side and i have had no further issues. Twin 700's move massive air but at idle in stop and go traffic they place an extreme burden on the alternator. This is just my experience, I am now running the DENSO 6860 220 amp alternator with overdrive pulley and all the big grounds/feed cables and can sit in stop and go extreme summer heat with ac on max and not have any issues.

Thank you for clearing up that last part as it was going to be my next question. A lot of the new guys out there think that “a bigger alternator will be better!”
No…not always. Sometimes that’s only the case if you match the pulley to it, and for someone who doesn’t change their own oil or couldn’t tell you where the water pump is located, I’m guessing they don’t have the tools for removing the harmonic balancer. Note to the new guys: don’t let this sway you! Use this as an excuse to learn new things and the reason why you need to buy new tools.

 

[thompsoj22]

Thank you for clearing up that last part as it was going to be my next question. A lot of the new guys out there think that “a bigger alternator will be better!”
No…not always. Sometimes that’s only the case if you match the pulley to it, and for someone who doesn’t change their own oil or couldn’t tell you where the water pump is located, I’m guessing they don’t have the tools for removing the harmonic balancer. Note to the new guys: don’t let this sway you! Use this as an excuse to learn new things and the reason why you need to buy new tools.

Actually it is the alternator pulley that I change, The OEM is 2.45 and the overdrive is 1.93. I advise this to just about anyone who wants more amps at idle. Will it wear the alt quicker? On paper yes as it spins faster but in reality the higher rpm increases the internal fan speed, Lowering the op temp of the critical parts, diodes/solid state internal voltage regulator and extending their service life. Our vehicles basically are always below 2000 rpm at cruising speed so you will never risk over speeding the alt for any extended duration.

 

[alpha_omega]

Actually it is the alternator pulley that I change, The OEM is 2.45 and the overdrive is 1.93. I advise this to just about anyone who wants more amps at idle. Will it wear the alt quicker? On paper yes as it spins faster but in reality the higher rpm increases the internal fan speed, Lowering the op temp of the critical parts, diodes/solid state internal voltage regulator and extending their service life. Our vehicles basically are always below 2000 rpm at cruising speed so you will never risk over speeding the alt for any extended duration.

Wait…so you’re buying a bigger (stronger) alternator, then changing the pulley that comes with it to an overdrive, but not changing the main drive pulley to an overdrive?

 

[Geotrash]

Wait…so you’re buying a bigger (stronger) alternator, then changing the pulley that comes with it to an overdrive, but not changing the main drive pulley to an overdrive?

I'm confused... why would you? If you're looking to spin the alternator faster, then you only need to change the alternator pulley to one with a smaller diameter (overdrive) to make that happen.

 

[mikeyss]

I have dual batteries with the stock alternator. At idle, I don't have any issues at all.

 

[thompsoj22]

Wait…so you’re buying a bigger (stronger) alternator, then changing the pulley that comes with it to an overdrive, but not changing the main drive pulley to an overdrive?

Yes, I only want to increase the alternator speed. This is an effective modification even with the DR44 160 amp stock alternator. Only the high rpm builds are under driving at the crankshaft. IMO?

 

[thompsoj22]

I have dual batteries with the stock alternator. At idle, I don't have any issues at all.

I'm confused... why would you? If you're looking to spin the alternator faster, then you only need to change the alternator pulley to one with a smaller diameter (overdrive) to make that happen.

You are absolutely correct! The DENSO 6860 is rated to provide 220 amps, The DR-44 is rated to provide 160 amps. Some people like big tires, Others big horsepower or torque, Others big stereo's. Me I like big current! Lots and lots of available current. We live in the high desert and June through August it will likely average 105 to 113 degrees every single f'ing day! I also like to run max front/rear ac and it is common for us to sit in the vehicle at idle for extended periods while running errands around town. Even with my setup i can see a small trace of belt dust on the front of the alternator housing which is an indicator of how much torque is required to spin the alternator with the applied current draw. It works for me!

 

[Doubeleive]

So for future reference I just measured the cfm of the 700w 7/9 rimmed blade (k5l) fans both sides measured approx 2300 cfm on high, measured inside the engine compartment right up against the fan, can anyone measure the dual 5 blade non rimmed 700w? You just need a anemometer

 

[mikeyss]

So for future reference I just measured the cfm of the 700w 7/9 rimmed blade (k5l) fans both sides measured approx 2300 cfm on high, measured inside the engine compartment right up against the fan, can anyone measure the dual 5 blade non rimmed 700w? You just need a anemometer

I wish I had something to measure CFM , because I have the 2011 and up K5L 5 blade rimless 700w fans in my 09 tahoe, and I have the 7/9 rimmed 700w on my 06 Sierra Denali. The fans from the 2011 are much louder and feel like they suck more air in compared to the 06 7/9 setup but they are much quieter.

 

[Doubeleive]

I wish I had something to measure CFM , because I have the 2011 and up K5L 5 blade rimless 700w fans in my 09 tahoe, and I have the 7/9 rimmed 700w on my 06 Sierra Denali. The fans from the 2011 are much louder and feel like they suck more air in compared to the 06 7/9 setup but they are much quieter.

I bought this one off of ebay $40, might not use it much but it can come in handy for other stuff since it also measures temperature
https://www.ebay.com/itm/164554574874

 

[Foggy]

So now that we are talking FANS....
I installed the TYC 622210 fans last spring. They are the 7/9 blade listed for "performance cooling".
My fan set up was a 7/7 blade assembly.. Not sure if it was the OEM setup... as I bought used.
Is there any way of knowing what the wattage is on these??? I do have the the HD cooling, towing,
etc options on my XL 6.2 denali.
I can't find specs on the TYC as far as wattage

 

[gooffeyguy]

My fans are loud as hell and feel like it's gonna suck you in when standing in front of the vehicle, but I don't have the K5L, just the standard bladed fans

 

[Doubeleive]

So now that we are talking FANS....
I installed the TYC 622210 fans last spring. They are the 7/9 blade listed for "performance cooling".
My fan set up was a 7/7 blade assembly.. Not sure if it was the OEM setup... as I bought used.
Is there any way of knowing what the wattage is on these??? I do have the the HD cooling, towing,
etc options on my XL 6.2 denali.
I can't find specs on the TYC as far as wattage

you would probably have to contact tyc they must have it in there technical data somewhere

 

[Doubeleive]

I wanted to check the cfm of both the 7/9 rimmed 700w and dual 5 blade 700w to see which one moves more air (or if they are the same), I don't care about the noise I have a nice stereo to turn up lol