Dual oil coolers for serious track duty

[Orange Crush 1LE]

Now I'm understanding why the C7 Z06 has been such a challenge for the GM engineers, it may be hard to find an aesthetic place to put oil coolers that also are high pressure on the new Vette.

I'm glad your machine is running cooler than before, still higher than I was expecting. My car's oil temp peaked in the 220s, even with the 514 RWHP heat generating motor. That was on a cooler day than you ran, so maybe my set up would hit oil temps in the 230s on a hot day. It also really shows the dramatic difference between the high pressure and low pressure areas of the grille. The high pressure openings really flow a lot of air. Agree with you that your temps are probably cool enough, especially on a motor that is close to stock. For a highly modded motor on a track car like I had, one would be wise to go with the dual oil cooler set up.

[X25]

Originally Posted by Orange Crush 1LE

Now I'm understanding why the C7 Z06 has been such a challenge for the GM engineers, it may be hard to find an aesthetic place to put oil coolers that also are high pressure on the new Vette.

I'm glad your machine is running cooler than before, still higher than I was expecting. My car's oil temp peaked in the 220s, even with the 514 RWHP heat generating motor. That was on a cooler day than you ran, so maybe my set up would hit oil temps in the 230s on a hot day. It also really shows the dramatic difference between the high pressure and low pressure areas of the grille. The high pressure openings really flow a lot of air. Agree with you that your temps are probably cool enough, especially on a motor that is close to stock. For a highly modded motor on a track car like I had, one would be wise to go with the dual oil cooler set up.

Those temps are great! The location for this oil cooler is pretty much where the radiators are, so one would hope for sufficient air flow.

For those who will install a big oil cooler like mine, I would highly recommend installing an oil cooler adapter with NO THERMOSTAT, and putting a high flow thermostat on the lines (Improved Racing has one like that). I think the problem is not necessarily air flow, but also the oil flow. That thermostat in that compact oil cooler adapter is pretty restrictive, and also seems to allow a bit of bypass regardless of temps. A thermostat on the line will not have such space limitations, greatly improving the flow.

[tadams72]

Well, looks like duals for sure now. Down here in SoCal track days are often in the 90's. Really appreciate the report though.

On the issue of coolant temps, I can't say definitively it is the case but the ECM is programmed to dial back power through changing timing and fueling events based on coolant temp. Other contributing PID's to dealing with heat might be IAT, knock, and even calculated PIDS. So if I were to guess, you hit the magical combination of parameters that made your ECM pull timing and add fuel to help cool the motor. This would equate to coolant temp coming down and likely you would see that also in your lap times unless you were over-powering your entries before and now your driving has become more fluid with better entry speed and roll through if that makes sense.

Again, big thanks to X25 and OrangeCrush. You're being the guinea pigs is going to save me some time, money and frustration on my build.

[X25]

Originally Posted by tadams72

Well, looks like duals for sure now. Down here in SoCal track days are often in the 90's. Really appreciate the report though.

On the issue of coolant temps, I can't say definitively it is the case but the ECM is programmed to dial back power through changing timing and fueling events based on coolant temp. Other contributing PID's to dealing with heat might be IAT, knock, and even calculated PIDS. So if I were to guess, you hit the magical combination of parameters that made your ECM pull timing and add fuel to help cool the motor. This would equate to coolant temp coming down and likely you would see that also in your lap times unless you were over-powering your entries before and now your driving has become more fluid with better entry speed and roll through if that makes sense.

Again, big thanks to X25 and OrangeCrush. You're being the guinea pigs is going to save me some time, money and frustration on my build.

You're very welcome, and let us know how it goes!

Regarding using inline thermostat, Michael @ImprovedRacing doesn't think it would make much of a difference:

Glad to hear you finally got that sorted out. I guess these cars just need a lot of cooling.

Whether you run the thermostatic adapter or the inline thermostat, I don't think it would make much of a difference. The inline one flows better, but the thermostatic adapter would have a lower pressure drop in bypass mode at low temps because it's closer to the block (so no pressure drop from flow through the lines). The adapter also saves money and weight, and reduces hose ends and connections.

Anyway, this is good info as we now know what it takes to keep these cars in check at the track. When we make our Camaro oil cooler kit we will look into a cooler of similar size.

Regarding coolant temps, FYI, Synner posted this on my build thread.

Originally Posted by Synner

My water temps hit 240-250 a couple sessions in a row. That was still on the dinky 245/275 tires but temps were 95ish. I called it an early day after seeing what my water and oil temps were doing. This was prior to all my cooler upgrades.

228 is right around the 100% on fan setting, that's probably what you're noticing.
From a stock 2010 LS3 tune:
192-210 f. = 24% fan speed
214 f. = 26% fan speed
217 f. = 40% fan speed
221 f. = 51% fan speed
225 f. = 65% fan speed
228 f. and above = 91% fan speed

Regarding timing/power v.s. coolant temps" I do have an uncut version of my last session, and you see the climb of temps around lap 3-4, and the subsequent quick drop in temps. Whatever the case, my trap speeds seem to be pretty constant, making me believe that I do not lose power. I'm wondering if my OEM thermostat gets a bit stuck, and opens all the way only when heated up a bit:

[tadams72]

Originally Posted by X25

You're very welcome, and let us know how it goes!

Regarding using inline thermostat, Michael @ImprovedRacing doesn't think it would make much of a difference:


Regarding coolant temps, FYI, Synner posted this on my build thread.


Regarding timing/power v.s. coolant temps" I do have an uncut version of my last session, and you see the climb of temps around lap 3-4, and the subsequent quick drop in temps. Whatever the case, my trap speeds seem to be pretty constant, making me believe that I do not lose power. I'm wondering if my OEM thermostat gets a bit stuck, and opens all the way only when heated up a bit:

Well fan speed could be what you're seeing then. I've got mine tuned to come on at 100% much sooner. Stands to reason what Synner is saying though. Good to know about the high flow thermostat. Was thinking that might help but going to try the dual cooler setup first.

[Woodsman44]

This is certainly disheartening news. What do you guys think if the dual coolers were side by side in the center of the lower grille rather than on either side of the lower grille? You could use aluminum sheeting to force the air through the coolers but it would basically block or slow down all air flow from the lower grille to the radiator. I just put brake ducts on the sides with plans to have the oil cooler where X25 has his.

[X25]

Originally Posted by Woodsman44

This is certainly disheartening news. What do you guys think if the dual coolers were side by side in the center of the lower grille rather than on either side of the lower grille? You could use aluminum sheeting to force the air through the coolers but it would basically block or slow down all air flow from the lower grille to the radiator. I just put brake ducts on the sides with plans to have the oil cooler where X25 has his.

One thing worth trying is to move the cooler core adjacent to the A/C condenser. As is, I have about 2" space in between, which is not ideal. It would be nice if I could try the dual setup as well in same conditions and see how it fares, but that's not an easy change.

I'm still wondering how my brother's system will fare when we install my Series 1 72 row core to the very bottom, and install it in addition to the OEM cooler, not as a replacement.

[Woodsman44]

X25 - I was taking a look at my setup this morning since I received the same oil cooler you're using, last night. One big difference I'm seeing between the the big single vs. the dual setup (since they have the same total cooling capacity) is the airflow. The dual setup has air being forced to the entire surface area of each cooler at a high velocity. The big single cooler has a big dead spot behind the bumper bar and air isn't being funneled directly to the cooler. I wonder how much lower your temps would be if you funneled the air on all 4 corners of your oil cooler. There also might be a away to funnel some of the air to the dead spot with some aluminum sheeting about 2" above and below the bumper bar, the lower one angled up and the upper one angled down. It will take a little bit of the fresh air from the radiator but it'll still hit it at some point just a little warmer.

I still haven't decided what I'm going to do but I need to decide quickly so I'm able to return what I have. Another thought is to go with a dual setup and put one above the bumper bar and one below with aluminum sheet forcing air to both. It'll take up most of the fresh air to the radiator. Or I can try what I just recommended with the big single but I can't return it once I've tried it. Any help is appreciated.

[X25]

A few remarks:

• Install it as close to radiators as possible: Cars always have multiple radiators, and it works just fine as long as you have enough flow to do all the cooling work you need. One issue is that you would disturb the air flow as you add radiators (or cooler cores) to arbitrary locations. If you place the oil cooler core as close as possible, but not touching to the A/C condenser, you'd ensure the air that flows through your oil cooler would also flow through the other radiators; not just get lost in turbulence. I'd not worry about coolant temps; without the OEM oil cooler, radiator has a lot more headroom anyway.
• The beam: There is no getting away from it, and it looks even bigger (relative to the opening) for 2014+ models with the smaller top air opening. In line with the idea of staying close to the radiators, further away from the beam can allow more air flow since the air rushing in from the bottom will have to tilt up (exiting from the hood louver).
• The experience: I should note here that the driving style also has a lot to do with the oil temps. High RPMs seem to be the main component, and it makes a high difference when one car is driven a little bit higher in average RPMs. There was another Camaro forum member attending the very same track day with his ZL1, and he was a bit less aggressive in shifting points; he stated he never exceeded 250 degrees F oil temp while I was in the 270s!

TL;DR: If you will install, try to do so as close to the A/C condenser as possible (without making it touch). This will both increase air flow to the oil cooler (you need to be as far back from the beam as possible), and also reduce chances of air turbulence to the other radiators.

[hcsi99]

This is only a teaser. I'd like to try to keep as much of this relevant as possible because we have a long list of what doesn't work, so far warning my latest set up has not been track tested yet.
In my first attempt at better oil cooling I ran a single Earls 41600 16 row oil cooler with AN10 lines using the improved racing oil cooler adapter with 180 degree thermostat. It was mounted with half of it blocked by the front bumper beam. It was maybe 5 inches from the bumper beam, and 5 inches from the AC condenser. It did not work well.



For my next attempt I've added another Earls 16 row, notched and boxes the front bumper crash bar, notched the plastic bumper in front of the crash bar but behind the fascia to allow for more air flow. I've also mounted the coolers a 1/2 inch from the condenser.




All of the oil pressure reading are in line with GM specs as far as hot minimum psi at a specific RPM. Street temps seem to be around 20 degrees cooler as well. My next track day is tomorrow so stay tuned for results.

[tadams72]

Originally Posted by hcsi99

This is only a teaser. I'd like to try to keep as much of this relevant as possible because we have a long list of what doesn't work, so far warning my latest set up has not been track tested yet.
In my first attempt at better oil cooling I ran a single Earls 41600 16 row oil cooler with AN10 lines using the improved racing oil cooler adapter with 180 degree thermostat. It was mounted with half of it blocked by the front bumper beam. It was maybe 5 inches from the bumper beam, and 5 inches from the AC condenser. It did not work well.



For my next attempt I've added another Earls 16 row, notched and boxes the front bumper crash bar, notched the plastic bumper in front of the crash bar but behind the fascia to allow for more air flow. I've also mounted the coolers a 1/2 inch from the condenser.




All of the oil pressure reading are in line with GM specs as far as hot minimum psi at a specific RPM. Street temps seem to be around 20 degrees cooler as well. My next track day is tomorrow so stay tuned for results.

Looking much more efficient. How close to the a/c condenser is the setup? That seems to be key to the cooling potential by limiting turbulent air. Also, I've seen a lot of people cutting and boxing the crash bar but only one guy has actually cut in through the bumper fascia for the air flow. What's your plan? Thanks.

[X25]

Great, you seemed to have placed it right (very close to the radiators, as low as possible). One tiny little nit-pick: I wish we could have the ports on the sides with these cores (like Justice Pete's core), so the lines would not interfere with the flow, either.


Fingers crossed! : )

[hcsi99]

tadams72, I've got it mounted about a half inch from the AC condenser, as far as the front bumper cover, see the picture below, don't ask why the old cooler is back on the left, I'll break it all down when I write the thread if this all works.
X25, I've got my fingers, toes, eyes, and legs crossed.


Should be enough air flow, I hope.

[X25]

Originally Posted by hcsi99

tadams72, I've got it mounted about a half inch from the AC condenser, as far as the front bumper cover, see the picture below, don't ask why the old cooler is back on the left, I'll break it all down when I write the thread if this all works.
X25, I've got my fingers, toes, eyes, and legs crossed.


Should be enough air flow, I hope.

While at it, you might want to get the heritage grill, too. Considering even the flow-tie is claimed to have an impact of a few degrees F in track temps (claimed by GM; don't remember the reference link), it might make a difference.

Under sunlight, you can't even see it!


Guys, please report us back with your running temps, oil pressures, etc. Every car that I've ever owned always hit at least 270 degrees, even my older '06 C6 Z06 with its large air-to-oil cooler and much better air flow. I'm starting to think the tracks here are just not good for cooling with their short straights, and I would love to get more data from you. If this dual cooler set-up works like OP's, it could make an excellent choice since it would also be easier/safer to install, and leave the side air flows to the brake ducting.

Besides these, I had to do extensive work (improving ducting for the radiators, removing thermostat, etc.) to get a hold of temps on my supercharged Miata, so there are always solutions : )

From my Miata build:

Originally Posted by X25

Wow, working on ducting is so much fun!

This is stock ducting. Notice the big hole on the left and the huge openings up front that connects this chamber with where the fog light reside. The end of it is also not completely sealed.


Front gaps blocked, and the end sides also properly closed.


No more huge gaps on the sides of anywhere else!