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Cooling for warmer climates / race cars

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captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
I've struggled recently with cooling on my new build. Here's the summary of what I have:

  • 470rwhp Coyote engine, 7800rpm max rev
  • Fluidyne and Mishimoto radiators (the cores are identical)
  • Oem thermostat
  • Kooks jet-hot coated headers, other heat control materials around the engine
  • Fully ducted radiator boxing on the front side, seals to bumper cover and to radiator
  • GT500 radiator fan
  • Setrab 948 cooler setup in radiator box, 2" gap to radiator
    12 boss 302S style grille (more open than 302S) and full mesh grilles
  • OEM and Meziere electric water pump.
  • Tiger racing vented hood
Some images: (nomex is seen on the oil cooler section, but not the radiator - was added later)
1589158932041.jpeg
(old radiator seen here for mockup, was changed to the mishimoto for actual running)
1589158974841.jpeg

1589159146267.jpeg

I did some recent testing in 90-93* weather, and in 4-5 laps on a particular track (4530' elevation), I could get my oil to touch 290 degrees on a hot-side measurement (there would be a 7-13 degree cool side delta returning to the motor). It didn't get much higher

Grille change was worth 7 degrees in water temps but not as much on oil temps. The mechanical water pump was slightly better water temps

While I feel I've thrown everything at it, I'm not sure what would be the recommendations to improve this further.

Here is some data:
Session 1, lap 3 (electric water pump, mesh grille, but did have nomex radiator protector installed)
1589158169886.png
1589158195707.png

Session 2, lap 3 : (oem water pump, mesh grille, removed nomex, 2 degrees cooler track temp)
1589158433199.png
1589158474705.png

In my examples, I'm only 3 laps in and the car's still warming, but I thought it would provide meaningful insight (each session I shut it down on the next lap and brought it in)
  • My thoughts are:
    Am I not getting enough air through the radiators?
  • Is that flow restriction on the back side of the radiator (the oem fan and shroud, despite the gt500 flap vents)
  • or is it on the front (the bumper cover, the radiator being shrouded by the oil cooler, not enough oil cooler exposed to grille)
The electric water pump was nice, but it is 5* warmer on average (though how much of that was from the nomex?), and it was really nice to cool the engine post session, but if the stock cooler does as well, why have this big spendy part?

What recommendations are there to cool this thing more effectively? I did experiment with short shifting, but that just made me slower and not noticeably cooler.
 
1,289
1,113
Exp. Type
HPDE
Exp. Level
5-10 Years
Philly Metro Area
How far back does your splitter go? I ask because @Mad Hatter posted that he encountered higher engine temps when he had his splitter extend far back.


Also, I assume your Engine Temp graphs are coolant temps?
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
How far back does your splitter go? I ask because @Mad Hatter posted that he encountered higher engine temps when he had his splitter extend far back.


Also, I assume your Engine Temp graphs are coolant temps?

Cylinder head temp - engine temp in the above graphs.

the splitter uses the oem mid and rear trays, doesn’t close off any of the engine bay. Something I thought about as I’m working on getting a single piece splitter developed this year.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Just throwing these out there:

1. Test your OEM Thermostat to make sure its opening fully
2. Is your lambse set to .82 or .83?
I have validated the thermostat operation (used a new one on the build and validated its operation on the dyno and during bleed operations)

.82 - the tune has some enrichment for safety margin
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Interesting on how the 2nd IAT graph shows much more variability than the first one. But the changes you made should have little or no effect on IAT.

there’s some junk in the data, but if you were to ignore the low points and smooth the curve, you could infer it was a somewhat cooler session.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Also, maybe this Ford high flow water pump can help:


But if the issue is your radiator doesn't have enough air flow thru it, it may not matter how fast the water is recirculated.

agree, I might try this part next, the mechanical pump I used was just a gen 2 oem unit.

for the radiator flow, I’m curious if the oem fan shroud is helping or hurting for my purposes
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Isn't the fan shroud primarily there for low speed operation?

That is my understanding as well. On a SN95 car, I had some overheating issues in traffic when I went to a spal fan and large aftermarket radiator, but once I shrouded it, temperatures decreased significantly.

That said, if I can improve the on track cooling through shroud removal, how much trouble am I getting into coming off track where the car is nearly at its most hot and cooling effectiveness is at its least?
 
1,289
1,113
Exp. Type
HPDE
Exp. Level
5-10 Years
Philly Metro Area
Do you have an actual coolant temp sensor? With CHT I think that the car will go into limp mode at with 245° or 255°. You seem to have a little cushion before that will happen.

As far as your oil temps, is your sensor on the sandwich plate? To put one on the hot side of my sandwich plate I'd have to install a 90° fitting and extension to avoid the sensor hitting the alternator. I've also considered teeing it off the oil pressure port. Either way it seems the sensor would be shrouded and not subject to full flow of oil. Others on TMO (and my tuner) have said the sensor should be in the sump - such as replacing the low oil level sensor.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
I have two oil temp sensors, both in direct flow of oil:

one is in the remote oil filter housing on the intake side (prior to filter), this is my "hot" reading; the other is in the ford performance oil line adapter block going back into the motor (though I might move it into a line adapter nearby to get it a bit more separated as the block adapter is made of aluminum and while it is reading from the return side, it probably picks up a bit of heatsoak from the housing itself)
 
277
161
Im thinking a radiator change/upgrade along with the water pump upgrade. Ron Davis is local and might be a option.
 
173
38
I always struggled with keeping the oil temp under control.
The stock cooler was efficient enough to overheat the coolant so I added the
FR Boss 302 setup Setrab 915.That helped quite a bit but cost about 10 lbs of oil
pressure.With that setup I could push pretty hard, but I don't want to see my oil
above 270 on the hot side.
Next I tried a 172 and eliminated the OE cooler.Big mistake,I could overheat the oil in 3 laps on a 50 degree
day.I was running the 302S grill and pulled it out to finish the day.That made a huge difference and I was able to finish
the day.
Next step was a Ford Racing radiator and a Setrab 948.I also changed to a Roush bar style grille that has about twice the open area
of the 302S grille.I also added a curved blade in the middle of the upper grille to direct more air to the oil cooler.
That setup worked pretty well but I could still get to 260 oil temp if I was pushing.
I've always thought that the air just couldn't get through the engine compartment
because of how tight it is around the engine.
Since I already had a replacement hood I decided to add the Trackspec hood vent.
That solved my oil temp problem usually 220-230 running hard.
Hope this helps.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Some thermal maximum data, I cleaned up the bad IAT signal, but this isn't apples to apples as its the hottest lap from each day, but you can see the LAP3/electric water pump lap is still increasing in temperatures (and had a higher IAT for the day). So I do not know what the thermals would look like had I kept going to 5 laps.
1589222600286.png

Working on the lap3 vs lap3 data now.
 

captdistraction

GrumpyRacer
1,954
1,698
Phoenix, Az
Now we are getting somewhere, lap 3 electric, lap 3 mechanical water pump sessions:
1589223192851.png

Some conclusions can be drawn against this data:

  1. the Water temp delta has little impact on the oil temp delta
  2. The mechanical water pump is slightly more effective than the electric IF you don't consider the difference in IATs (which may point to cooler track temperatures at the time, I don't have an hourly almanac and I didn't record the ambient temp sensor). The second day may be 3 degrees cooler
  3. Track configuration is different, but the data is pretty similar
changes between the two were noted as:
  • Switch from electric water pump to mechanical
  • both used the higher flow grille
  • nomex was removed from the radiator on the mechanical pump lap

Based on this, the pumps aren't doing much different out of this data set. Had I run it longer to see if I could hit a more flat oil temp line I could infer if there's a delta between the two.
 
Last edited:
1,289
1,113
Exp. Type
HPDE
Exp. Level
5-10 Years
Philly Metro Area
If it helps, historical hourly temp, humidity, and density altitude info can be found at sites like:


I don't know which track you're at but I filtered the list for Pacific Coast and road course tracks and got lists by states. I then picked AZ Motorsports Park and then "historical"

 

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