HE fan food for thought.
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JE_Delta (07-21-2019)
07-21-2019, 07:12 PM
#2
Senior Member
DOB used to generate a lot of discussion regarding heat exchanger systems over at s197forum. I agree with a lot of their thinking, some I don't...at least as it relates to how fast the water moves through the intercooler and heat exchanger. I know it's not the topic of the article, but it's also another factor to consider in effective HE loops.
I didn't read the full article, as it was obvious from the start what the results are. As far as HE water temps are concerned, it's nowhere near a 1 to 1 ratio of reduced fluid temps to air intake temps....it's quite a bit higher than that, from my experience, although I couldn't give an actual ratio. There are many variables that effect temperatures.
Perhaps ideally smaller fans could be used on the parts of the heat exchangers that were blocked from air flow, as I have on my lower stock roush heat exchanger. I may try removing the upper fan that's behind the upper heat exchanger to see if there's any detectable difference at some point just for the fun of it.
I didn't read the full article, as it was obvious from the start what the results are. As far as HE water temps are concerned, it's nowhere near a 1 to 1 ratio of reduced fluid temps to air intake temps....it's quite a bit higher than that, from my experience, although I couldn't give an actual ratio. There are many variables that effect temperatures.
Perhaps ideally smaller fans could be used on the parts of the heat exchangers that were blocked from air flow, as I have on my lower stock roush heat exchanger. I may try removing the upper fan that's behind the upper heat exchanger to see if there's any detectable difference at some point just for the fun of it.
07-21-2019, 10:58 PM
#3
There is no question the body of air produced by a vehicle in motion far exceeds any amount of air a cooling fan could provide.
However the biggest benefit from a fan is when the vehicle is not in motion, such as when waiting in the staging lanes or in stop and go traffic.
My cruising and WOT iat2 temps did not change after I installed the Roush heat exchanger cooling fan, but my around town low speed temperatures definitely improved. Did it have any real world impact on performance? Not really, at least in any form that matters, but I like knowing when I pull out of the Whataburger drive through and pin it to merge onto the highway my IAT’s are 20 degrees lower then they would have been without the fan.
But they bring up a valid point about fans blocking airflow at speed. Care must be taken to limit this restriction.
However the biggest benefit from a fan is when the vehicle is not in motion, such as when waiting in the staging lanes or in stop and go traffic.
My cruising and WOT iat2 temps did not change after I installed the Roush heat exchanger cooling fan, but my around town low speed temperatures definitely improved. Did it have any real world impact on performance? Not really, at least in any form that matters, but I like knowing when I pull out of the Whataburger drive through and pin it to merge onto the highway my IAT’s are 20 degrees lower then they would have been without the fan.
But they bring up a valid point about fans blocking airflow at speed. Care must be taken to limit this restriction.
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TX-Ripper (07-23-2019)
07-22-2019, 10:16 AM
#5
I wonder how much difference there is car vs truck? Aren’t the car HE’s largely blocked already by the front bumper where our trucks are pretty much wide open to the front, especially if you run an EcoBoost bumper insert. Obviously there’s still some blockage but wouldn’t the openness of the truck make it less of an issue?
07-22-2019, 04:02 PM
#6
I wonder how much difference there is car vs truck? Aren’t the car HE’s largely blocked already by the front bumper where our trucks are pretty much wide open to the front, especially if you run an EcoBoost bumper insert. Obviously there’s still some blockage but wouldn’t the openness of the truck make it less of an issue?
Honestly I don’t think it is much of an issue either way, as long as the logged iat2 temperatures are good. The Whipple setups have a good heat exchanger placement, and even without fans benefit a little from the existing airflow from the primary cooling fan.
The Roush kits have decent flow at speed....none at low speeds, and it’ll be up the end user to determine if they need that increased cooling at low speeds.
07-22-2019, 04:57 PM
#7
Blown Member
On an 2018+ the fans benefit far out weigh having no fans. The 2018 has the Heat Exchange mounted up high in front of the radiator.
I run an Aeroforce gauge that I have set to monitor IAT and A/F. With this setup I don't have to log anything. I see it in real time all the time. I also have the original smaller Heat Exchanger that Whipple sent with my Stage 2 kit.
I can't tell if having the fans in place hurt the IAT when moving at a steady speed because it doesn't seem any different.
I can tell you there is a world of difference when I am not moving. After not moving for a while then giving it the gas the IAT drops really fast. The fans have kept air moving through the Heat Exchange and flowing through the Intercooler cooling the system down.
The heat generated by the engine with the throttle body closed makes the IAT rise but that heat is immediately flushed out when you start moving opening the throttle body. Without the fans it takes a while to cool down because the Intercooler system has heated up from no air flow.
I run an Aeroforce gauge that I have set to monitor IAT and A/F. With this setup I don't have to log anything. I see it in real time all the time. I also have the original smaller Heat Exchanger that Whipple sent with my Stage 2 kit.
I can't tell if having the fans in place hurt the IAT when moving at a steady speed because it doesn't seem any different.
I can tell you there is a world of difference when I am not moving. After not moving for a while then giving it the gas the IAT drops really fast. The fans have kept air moving through the Heat Exchange and flowing through the Intercooler cooling the system down.
The heat generated by the engine with the throttle body closed makes the IAT rise but that heat is immediately flushed out when you start moving opening the throttle body. Without the fans it takes a while to cool down because the Intercooler system has heated up from no air flow.
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07-22-2019, 11:48 PM
#8
I have always wanted to try towing with half of my radiator shroud and one fan cut out for the exact reason stated in the article. The total flow area through the fans is VERY small once you subtract the fan hub. I suspect the total flow area of the radiator(once you subtract the tubes and fins and ****) is larger than the opening in the fans. In fact I think I did the math assuming the radiator could flow 50% of the total area and the fans were technically a restriction.
And I know for a fact that when I converted my Jeep to an electric fan setup using a Derale, it was actually more prone to overheating at freeway speeds than with no fan at all.
That said, if you are not moving fast then having a fan is extremely important. Off-road and climbing steep winding roads would be a death sentence without fans.
And I know for a fact that when I converted my Jeep to an electric fan setup using a Derale, it was actually more prone to overheating at freeway speeds than with no fan at all.
That said, if you are not moving fast then having a fan is extremely important. Off-road and climbing steep winding roads would be a death sentence without fans.
Last edited by mass-hole; 07-22-2019 at 11:51 PM.