[travislambert]

With track days in extreme heat I'm seeing my oil temperatures exceed 290 F. There doesn't seem to be many great aftermarket options for ZL1 oil coolers. I've considered the Mishimoto kit for the SS, but I think that'll just move the problem.

My next thought was to build a custom oil cooler, but finding a good location for a heat exchanger is a challenge. I even considered a supplemental cooler on the coolant line just before the stock oil cooler. Along that same line of thinking, I then thought why not just upgrade the primary radiator. If I could reduce the coolant temps (currently maxing at about 240F), the OEM oil cooler would also work better.

The only candidate replacement radiator I could find was the C&R unit, but unfortunately, I can't find any test data to show it's actually better than stock.
https://wildhammermotorsports.com/16...or-c-r-racing/

Does anyone have any track time with the C&R radiator for the 6th gen ZL1?

[Joshinator99]

While I haven’t tried that radiator, just wondering what temps and fan speeds you have your cooling fan set for? I’m assuming you have a lower temp thermostat already too.

[travislambert]

Originally Posted by Joshinator99

While I haven’t tried that radiator, just wondering what temps and fan speeds you have your cooling fan set for? I’m assuming you have a lower temp thermostat already too.

I'm using the stock thermostat which I think is 194 or something like that. For road course the temps will always be above 194 so it's going to be open all the time anyway.

I can pull the tune and look, but I think I set the fans to be a little more aggressive after the thermostat is open. On the high temp side they're stock, but within a lap or so, I'll be at the max DC for the fans. Ramping the fans to max DC a little sooner probably won't make a significant difference.

[Badmojo]

Oil temps at 290 F are fine as long as you change the oil every 4-6 track events. I've done regular oil sampling and Valvoline MST 5W-40 has held up fine and wear metals are normal.

[travislambert]

Originally Posted by Badmojo

Oil temps at 290 F are fine as long as you change the oil every 4-6 track events. I've done regular oil sampling and Valvoline MST 5W-40 has held up fine and wear metals are normal.

I change my oil every track event for peace of mind and I think you're right about 290 F being okay. I'd just feel better about it if I could get the temps down some. I hate to beat on the car with oil temps that high.

[AD17SS1LE]

Originally Posted by travislambert

I change my oil every track event for peace of mind and I think you're right about 290 F being okay. I'd just feel better about it if I could get the temps down some. I hate to beat on the car with oil temps that high.

The high oil temps is exactly why I put mishimoto oil cooler on before I did any track days. I ran camarofest 2017 95 degrees 90% humidity all day and my max oil temp was 243. I didn't have my headers then but with headers max oil temp is 248. GM engineers said it was fine for oil temps to be 275-280 but I don't want my oil that hot. I don't know how fitment is on ZL1 but it fits very nice and has quality parts. If you do get one be sure to get the thermostatic control adapter with 200 degree thermostat so your oil can get over 200 before cooler opens up. I have a portion below from an engineer testing many oils as well as the link to full article

IDEAL OIL TEMPERATURE RANGE

.
An ideal oil sump temperature range is between 215*F and 250*F. If your sump temperature runs hotter than this range, you should add an oil cooler, or upgrade your oil cooler, if you already have one. This range is hot enough to quickly boil off the normal condensation that always forms during cold engine start-up, before that water dilutes the oil. And it is also hot enough to NOT promote the formation of sludge, like colder temperatures below the boiling point of water, can.
.
And that range is cool enough to do three things:
.
1. It is cool enough to keep the oil’s wear protection capability at the highest level achievable by that oil.
.
2. It is cool enough to provide critical cooling for engine components, which of course are directly oil cooled. Remember, engine components are only indirectly water cooled.
.
3. It is cool enough to keep most oils below their onset of thermal breakdown point.
.
But, motor oils do NOT stop working the instant they reach their onset of thermal breakdown point. However, it is not a good idea to run oil above its thermal breakdown point for extended periods of time. Because that will degrade its capability more and more as time/mileage goes on.

.
https://540ratblog.wordpress.com/

[travislambert]

Originally Posted by AD17SS1LE

The high oil temps is exactly why I put mishimoto oil cooler on before I did any track days. I ran camarofest 2017 95 degrees 90% humidity all day and my max oil temp was 243. I didn't have my headers then but with headers max oil temp is 248. GM engineers said it was fine for oil temps to be 275-280 but I don't want my oil that hot. I don't know how fitment is on ZL1 but it fits very nice and has quality parts. If you do get one be sure to get the thermostatic control adapter with 200 degree thermostat so your oil can get over 200 before cooler opens up. I have a portion below from an engineer testing many oils as well as the link to full article

IDEAL OIL TEMPERATURE RANGE

.
An ideal oil sump temperature range is between 215*F and 250*F. If your sump temperature runs hotter than this range, you should add an oil cooler, or upgrade your oil cooler, if you already have one. This range is hot enough to quickly boil off the normal condensation that always forms during cold engine start-up, before that water dilutes the oil. And it is also hot enough to NOT promote the formation of sludge, like colder temperatures below the boiling point of water, can.
.
And that range is cool enough to do three things:
.
1. It is cool enough to keep the oil’s wear protection capability at the highest level achievable by that oil.
.
2. It is cool enough to provide critical cooling for engine components, which of course are directly oil cooled. Remember, engine components are only indirectly water cooled.
.
3. It is cool enough to keep most oils below their onset of thermal breakdown point.
.
But, motor oils do NOT stop working the instant they reach their onset of thermal breakdown point. However, it is not a good idea to run oil above its thermal breakdown point for extended periods of time. Because that will degrade its capability more and more as time/mileage goes on.

.
https://540ratblog.wordpress.com/

I think the Mishimoto oil cooler unit is fine for the SS, but not so much on the ZL1. There are some fitment issues on the ZL1 and the heat exchangers are already stacked 3 deep. Adding a 4th layer seems to be questionable. At some point the air will be saturated with heat and the heat will just migrate into the other heat exchangers. I assume these reasons are why they specifically only advertise this unit for the SS.

If I go with an standalone oil cooler, I'll likely make a custom unit that mounts elsewhere.

I reached out to C&R for test data on their radiator. They responded quickly and said that they might have data from testing with the Holden Commodore which they believe to have the same (or at least similar) radiator. They are supposed to get back with me later, but who knows if I'll ever hear back. Guys looking for data who will likely validate results after the purchase are often avoided by aftermarket companies.

[kropscamaro16]

i looked at it before they are local to me and i work in the industry so can probably get a better deal lol

[AD17SS1LE]

I don't blame you for not wanting to have a 4th layer on top of your radiator and heat exchangers. There is not much room under these cars as well. Good luck with your custom radiator, maybe you can flush mount it in belly pan somewhere like the factory trans cooler.

[h018871]

I don't have any experience with it but Weapon-X has a kit that includes a larger aux radiator. I have been thinking about it, but the full kit is pricey. I need/will contact them about selling the aux radiator by itself. I'd be ok getting both of the aux pieces if offered. Adding the larger main intercooler, I think, would add more heat to the front of the AC and main radiator.

[travislambert]

Originally Posted by h018871

...Adding the larger main intercooler, I think, would add more heat to the front of the AC and main radiator.

Yeah! I think you are exactly right. I've certainly considered this as I already have an upgraded center heat exchanger and auxiliary radiators. Of course, the aux radiators should be no problem, but I've wondered if I've caused some of the problem by upgrading the center heat exchanger for the supercharger.

In addition to the heat simply moving from one exchanger to the others as you mention, when the IAT2 temps are lower, the engine is going to run with more timing, burning more fuel, and producing more heat. By upgrading only a portion of the cooling components, it throws the whole system out of balance. If I had left the main heat exchanger for the supercharger alone, the IAT2 temps would be higher, but the engine wouldn't be running quite as hard (making it easier for the rest of the cooling systems to keep up). I would probably see lower coolant and oil temps with a smaller heat exchanger for the supercharger (as crazy as that sounds).

The alternative is to upgrade everything and try to maintain the balance that way. That's what I'm looking at doing.

[h018871]

I'm interested in your experience after the main radiator upgrade

[travislambert]

Originally Posted by h018871

I'm interested in your experience after the main radiator upgrade

I'm not sure that upgrade is going to happen unless someone brings a worthwhile upgrade to market.

I reached out the C&R and they recommended that I go with an oil cooler instead of a primary radiator upgrade. They could have easily tried to sell me on their radiator, but they didn't. They basically told me their radiator would add mass and would delay the temperature rise, but the overall cooling capacity for road course use would be very similar to stock. They said that the stock radiators are extremely good.

What a breath of fresh air. An honest aftermarket company that acknowledges OEM quality.

In the conversation, I learned that C&R provides many OEMs with heat exchangers. If they're an OEM provider, you know they must make a quality product. With the service and responsiveness, I must say I'm really impressed with these guys.

[h018871]

Like you say, that is refreshing

Do you think you'll go back to the OE main intercooler?