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2018 F150 3.5 Ecoboost Platinum FX4 10-speed w/max tow, stock tune, Mishi CAC
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When I think about things like running 87 octane gas, hot inlet air temps, ecu retarding timing and dumping in fuel, I see these as sort of “bad ways to detune the engine”, essentially reducing performance and forcing a slow down.

I can already do that by simply applying less pressure on my right foot, and finding a lower gear, and slowing down. I’m hoping to at least reduce the need to do this so often.
 

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I need pictures to try an understand things, so I sketched up this little diagram of the cooling air flow on my 2018 Platinum. It is purely conceptual (I have no wind tunnel data to confirm), but I think it must be more or less what happens. The only thing that is not on my year model is the tranny cooler, but I showed it here because I know trucks w/o the 10r80 have it in this area.

AirFlow.JPG


I believe there is pressure drop across each element in this diagram (from right to left) that affects the airflow to some degree. I also believe that at some point the pressure bubble forms and redirects air around the truck. This is certainly true when the shutters are closed.

In terms of maxing fuel economy, Ford would have no incentive to design for additional airflow through the cooling system beyond whatever max cooling design case they use. They do have incentive to direct as much air around the vehicle as possible (thus the shutters).

So it still is unclear to me whether any meaningful mass flow improvement is available by reducing the pressure drop across the grille. There must be something, because it appears to me it is not a smooth/clear path for the airflow.

Neither are fully open shutters a clear path, although in looking closely at the blades it does appear they present somewhat of an aerodynamic shape to the airflow when fully open. Probably very minimal pressure drop in this position.

It is also not clear to me what positive or negative role the fan and fan shroud plays in our specific scenario. At some amount of natural airflow (vehicle speed), they must transition from being a help (eg pulling additional air through) to being another pressure drop in the overall system (overwhelmed by the higher airflow from vehicle speed).

I think what I’ve seen on various posts is that above a certain speed (eg highway speeds) they are “useless”. Does this mean they are actually adding pressure drop above a certain speed? Adding turbulence and restricting flow? If so, the implication is the cooling system would be better off w/o them (fans and shroud removed). However, others seem to be finding ways to make sure the fans are on high at highway speeds. Is this believed to still increase airflow? Or maybe ensure the fans “hurt” the least at highway speeds?
 

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I need pictures to try an understand things, so I sketched up this little diagram of the cooling air flow on my 2018 Platinum. It is purely conceptual (I have no wind tunnel data to confirm), but I think it must be more or less what happens. The only thing that is not on my year model is the tranny cooler, but I showed it here because I know trucks w/o the 10r80 have it in this area.

View attachment 168299

I believe there is pressure drop across each element in this diagram (from right to left) that affects the airflow to some degree. I also believe that at some point the pressure bubble forms and redirects air around the truck. This is certainly true when the shutters are closed.

In terms of maxing fuel economy, Ford would have no incentive to design for additional airflow through the cooling system beyond whatever max cooling design case they use. They do have incentive to direct as much air around the vehicle as possible (thus the shutters).

So it still is unclear to me whether any meaningful mass flow improvement is available by reducing the pressure drop across the grille. There must be something, because it appears to me it is not a smooth/clear path for the airflow.

Neither are fully open shutters a clear path, although in looking closely at the blades it does appear they present somewhat of an aerodynamic shape to the airflow when fully open. Probably very minimal pressure drop in this position.

It is also not clear to me what positive or negative role the fan and fan shroud plays in our specific scenario. At some amount of natural airflow (vehicle speed), they must transition from being a help (eg pulling additional air through) to being another pressure drop in the overall system (overwhelmed by the higher airflow from vehicle speed).

I think what I’ve seen on various posts is that above a certain speed (eg highway speeds) they are “useless”. Does this mean they are actually adding pressure drop above a certain speed? Adding turbulence and restricting flow? If so, the implication is the cooling system would be better off w/o them (fans and shroud removed). However, others seem to be finding ways to make sure the fans are on high at highway speeds. Is this believed to still increase airflow? Or maybe ensure the fans “hurt” the least at highway speeds?
I think the idea that the fans stay on was two fold:

  1. Some people think they may actually contribute to flow at freeway speeds.
  2. Others thing that they don't contribute to flow, but that having them on and spinning is better then them just sitting there freewheeling. IE, knowing they won't contribute, but make them less of a restriction. This was my thought in having 5Star lower my fan temperatures.
Evans Coolant was the first to say that they could actually be causing turbulence which means air is having a harder time navigating the engine bay and leaving.

Evans Coolant said:

It is possible that the fans running at speeds above 40 mph can create turbulence disrupting airflow through the engine compartment. Typically vehicle speed above 40 mph creates more airflow than an electric fan and even most mechanical fans. 1 sqft of radiator core area at 40 mph vehicle speed = 3520 cfm airflow. Unfortunately the airflow through the engine compartment gets restricted by a multitude of components and this amount of restriction is different with each vehicle. Best way to find out is to test.
I also had posted and article in another thread(Electric Fans on Radiators/Heat Exchangers) which was tailored to supercharger intercooler exchangers and fans, but same idea. The premise was that putting a fan on your intercooler only helped below 17mph. Through their testing, even the most powerful aftermarket fans only achieved an air velocity of 17mph. Then they put an intercooler core on a truck and measured air velocity pre and post cooler at 40mph vehicle speed with and without fans. Guess which one had higher exit velocity on the core.
 

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You're amazing. You can switch between g r a n u l a r <> summary easier than most.

But I really like the point you recently made that in cooler weather, our motors hardly struggle at all with shedding the heat necessary to climb those same hills.

Somewhere inside that fact is a reasonable approach to figuring out a solution.

Sent from my SM-G988U using Tapatalk
 

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I need pictures to try an understand things, so I sketched up this little diagram of the cooling air flow on my 2018 Platinum. It is purely conceptual (I have no wind tunnel data to confirm), but I think it must be more or less what happens. The only thing that is not on my year model is the tranny cooler, but I showed it here because I know trucks w/o the 10r80 have it in this area.

View attachment 168299

I believe there is pressure drop across each element in this diagram (from right to left) that affects the airflow to some degree. I also believe that at some point the pressure bubble forms and redirects air around the truck. This is certainly true when the shutters are closed.

In terms of maxing fuel economy, Ford would have no incentive to design for additional airflow through the cooling system beyond whatever max cooling design case they use. They do have incentive to direct as much air around the vehicle as possible (thus the shutters).

So it still is unclear to me whether any meaningful mass flow improvement is available by reducing the pressure drop across the grille. There must be something, because it appears to me it is not a smooth/clear path for the airflow.

Neither are fully open shutters a clear path, although in looking closely at the blades it does appear they present somewhat of an aerodynamic shape to the airflow when fully open. Probably very minimal pressure drop in this position.

It is also not clear to me what positive or negative role the fan and fan shroud plays in our specific scenario. At some amount of natural airflow (vehicle speed), they must transition from being a help (eg pulling additional air through) to being another pressure drop in the overall system (overwhelmed by the higher airflow from vehicle speed).

I think what I’ve seen on various posts is that above a certain speed (eg highway speeds) they are “useless”. Does this mean they are actually adding pressure drop above a certain speed? Adding turbulence and restricting flow? If so, the implication is the cooling system would be better off w/o them (fans and shroud removed). However, others seem to be finding ways to make sure the fans are on high at highway speeds. Is this believed to still increase airflow? Or maybe ensure the fans “hurt” the least at highway speeds?
Are you using powerpoint for your drawings? :ROFLMAO:

At work, if we don't have an actual detail/design drawing in Solidworks, we will use powerpoint to draw stuff up quickly for customers. You can get pretty detailed with it. My boss is a powerpoint artist.
 

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i see that the issue of slow towing is starting to be brought up and that's one of my biggest issues. Slow going with my 23ft. TT and I mean real slow, 10mph or slower motor will defiantly
heat up and that's where I would love to have a manual fan over ride switch to turn on the rad fans. Only change I have made to the truck, 2017 3.5, is a 180 thermostat which works
great until slow mountain climbing then temps shoot up. Even going down hill on a rough forest service road temps will go up unless I turn the ac to high kicking the fans on.

This brings me back to the idea mentioned several times on this thread that the stock fans are pretty weak. Crawling slow and ect's going up around the 215 mark the ac will bring
the temps down but not very fast, but turning off the ac and getting the truck up to 20mph, temps drop pretty fast. My son-in-law has a 2012 5.0 which is terrible at getting hot going slow,
crawling down a steep mountain road it will hit 220 in nothing flat, get the speed up and down goes the temps.
 

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2018 F150 3.5 Ecoboost Platinum FX4 10-speed w/max tow, stock tune, Mishi CAC
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Are you using powerpoint for your drawings? :ROFLMAO:

At work, if we don't have an actual detail/design drawing in Solidworks, we will use powerpoint to draw stuff up quickly for customers. You can get pretty detailed with it. My boss is a powerpoint artist.
I actually use Excel. The drawing and layout stuff in it are surprisingly powerful. Plus I can mix in text and calcs and charts etc if I want. I rarely find a situation where I need a more powerful (eg cad) app.

Note that I posted a couple of pics of grille mods on a stock photo of a 2018 Platinum a while back. Those mods were done in Photoshop, as Excel doesn’t really have good photo editing tools.

My other little favorite is the MS snipping tool thingie. I am constantly grabbing stuff from the web or sometimes even within Excel right from the screen and then pasting where I want.
 

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i see that the issue of slow towing is starting to be brought up and that's one of my biggest issues. Slow going with my 23ft. TT and I mean real slow, 10mph or slower motor will defiantly
heat up and that's where I would love to have a manual fan over ride switch to turn on the rad fans. Only change I have made to the truck, 2017 3.5, is a 180 thermostat which works
great until slow mountain climbing then temps shoot up. Even going down hill on a rough forest service road temps will go up unless I turn the ac to high kicking the fans on.

This brings me back to the idea mentioned several times on this thread that the stock fans are pretty weak. Crawling slow and ect's going up around the 215 mark the ac will bring
the temps down but not very fast, but turning off the ac and getting the truck up to 20mph, temps drop pretty fast. My son-in-law has a 2012 5.0 which is terrible at getting hot going slow,
crawling down a steep mountain road it will hit 220 in nothing flat, get the speed up and down goes the temps.
Yeah the stock fans are not programmed to turn on until around 217 I believe. You could retune it to lower the temp, but I would not be all that worried at those temperatures anyways. The truck will get that hot just sitting and idling in a parking lot.
 

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But I really like the point you recently made that in cooler weather, our motors hardly struggle at all with shedding the heat necessary to climb those same hills.
On the air exchange side, 3 things will improve radiator efficiency:

1) lower approach temp - tow at night or in winter, spray water on the stack (neither very practical)

2) higher mass flow - drive faster (increases heat production), reduce pressure drop and/or increase fans (subject of discussion)

3) greater radiator heat transfer surface area - increase cross sectional area (not practical), increase thickness (increases pressure drop)

No free lunches here.
 

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After all the discussion, my worklist to attack this specific part of the broader problem is still

1) Install the highest capacity radiator available that fits w/o major mods (I believe that to be the Mishimoto).

2) Take a stab at any pressure drop reduction I can get on the incoming airflow w/o doing anything drastic (maybe try minor grille mods).

I am anxiously awaiting any concrete solutions in the fan area.
 

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After all the discussion, my worklist to attack this specific part of the broader problem is still

1) Install the highest capacity radiator available that fits w/o major mods (I believe that to be the Mishimoto).

2) Take a stab at any pressure drop reduction I can get on the incoming airflow w/o doing anything drastic (maybe try minor grille mods).

I am anxiously awaiting any concrete solutions in the fan area.
I think with the fans, you are going to end up trading low speed performance for high speed performance.

My thought was to try and get fans that are shroudless and mount directly to the radiator, leaving all but the fan hub and blade area open to natural flow. Something like this:

168300


The problem is the fan no longer pulls through the entire core area at slow speeds.

My other thought was to put flaps in the fan shroud in any open spots. The Mustang GT500 had these from the factory. That way if the pressure in front of the fan is higher than in the engine bay, it will blow the flaps open and allow more flow area. If you are at slower speeds the fan will be pulling air and suck the flaps closed. I found some on Summit racing or jegs. I forget who makes them.

168301


The couple times I peaked at the stock fan shrouds, I did not see a lot of open space for flaps however.
 

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I think with the fans, you are going to end up trading low speed performance for high speed performance.

My thought was to try and get fans that are shroudless and mount directly to the radiator, leaving all but the fan hub and blade area open to natural flow. Something like this:

View attachment 168300

The problem is the fan no longer pulls through the entire core area at slow speeds.

My other thought was to put flaps in the fan shroud in any open spots. The Mustang GT500 had these from the factory. That way if the pressure in front of the fan is higher than in the engine bay, it will blow the flaps open and allow more flow area. If you are at slower speeds the fan will be pulling air and suck the flaps closed. I found some on Summit racing or jegs. I forget who makes them.

View attachment 168301

The couple times I peaked at the stock fan shrouds, I did not see a lot of open space for flaps however.
I like the concept. Simple solution. Does not really change OEM operation. Just a simple relief valve. Also, no real stress or mechanicals on the flaps. Fan sucks them closed, overpressure from natural airflow pushes them open.
 

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Well this is interesting ...

This is what Rockauto lists for a 2018 w/max tow

BB9E6F8E-42DF-46D0-8DCF-5BA702312EEE.png


This is what they list for a 2018 w/special vehicle package (whatever that is) ...

B4D9424E-3775-437E-99A8-A4B35CC74D61.png


Hmm...
 

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That is interesting.

Edit. I wonder if that is for the intercooler actually. Like the Raptor.
 

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Oh wait. The second one is the added fans on the Raptor cac. Duh.

So if natural airflow screws up the radiator fans at highway speeds, why isn’t the design of the radiator fans more like the Raptor cac fans?

And why would the tow package fans be different (they are) than the std radiator fans if the fans only deal with airflow at low speed?
 

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Oh wait. The second one is the added fans on the Raptor cac. Duh.

So if natural airflow screws up the radiator fans at highway speeds, why isn’t the design of the radiator fans more like the Raptor cac fans?

And why would the tow package fans be different (they are) than the std radiator fans if the fans only deal with airflow at low speed?
Because when you have a full shroud it lets the fans pull from the entire core. When its just an open shroud like the CAC fans it only pulls from right in front of the fan.

My guess is that the load on the intercooler is much lower at low speeds in general and so they don't need the fans to pull from the entire core.
 

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Yeah the stock fans are not programmed to turn on until around 217 I believe. You could retune it to lower the temp, but I would not be all that worried at those temperatures anyways. The truck will get that hot just sitting and idling in a parking lot.
Yep I know what temp the fans kick on but with an extended warranty 100k and 8yrs. not messing with any reprograming. Talked to the dealer about reprograming and they said that
it wouldn't effect the warranty as a whole but if something broke that could be in any way related to the reprograming yhen the warranty is void. They did say that some type of ecm
bypass switched was used that didn't involve unplugging the factory fan harness it shouldn't effect the warranty.

As for my current ect temps, I know they are ok but after seeing posts about warped exhaust manifolds I prefer to try to keep the temps down.
 

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Yep I know what temp the fans kick on but with an extended warranty 100k and 8yrs. not messing with any reprograming. Talked to the dealer about reprograming and they said that
it wouldn't effect the warranty as a whole but if something broke that could be in any way related to the reprograming yhen the warranty is void. They did say that some type of ecm
bypass switched was used that didn't involve unplugging the factory fan harness it shouldn't effect the warranty.

As for my current ect temps, I know they are ok but after seeing posts about warped exhaust manifolds I prefer to try to keep the temps down.
Ive yet to see warped manifolds on a 2017+ 3.5. That is an issue with the 1st gen 3.5(2011-2016). The bolt pattern and manifold on the second gen was redesigned.
 
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