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For our third session of the day, we added the auxiliary radiator back in the car, plumbed just as it had been previously. Engine -> Primary Rad -> Aux Rad -> Engine.
In short, it worked awesome. Water temps stabilized under 220°, with 95° incoming air. Oil temps were a little over 280°, and transmission temps stayed below 250°.
For our last test of the day, we planned to re-install the OEM oil cooler and see how well it would work with the super beefy water cooling system. We'll have results of that test up in our next post.
For our last test of the day, we planned to re-install the OEM oil cooler and see how well it would work with the super beefy water cooling system. We'll have results of that test up in our next post.
I really appreciate all the thorough research you guys are doing. I'm also someone who hasn't overheated the car to failure with the stock cooling. Since adding the secondary radiator all the temps have been fine except the trans temp getting a little higher than I like.
All that said, I've definitely noticed that the car makes less power when it's hot out and the lap times show it. I don't know that I'm experiencing heat soak per se as it seems to be relatively consistent through the session (most times) but it definitely is slower in the afternoon sessions than the morning sessions. If Aim can start logging IAT2 I'll start tracking that to see.
Given your latest post, what I'm wondering is whether simply replacing the GM secondary radiator with an equivalent sized intercooler laid flat would be a better solution that doesn't require cutting up the bumper. That would include removing the current intercooler from in front of the main radiator thereby making it more effective as well.
Do you have any thoughts on this? I realize that level I'm stressing the system is far less than you but for guys like me that might be a better compromise.
Our fourth and final test for the day involved a DeWitt 70mm prototype radiator, a GSpeed auxiliary radiator, and an OEM oil cooler (with no other changes to the supercharger intercooler system).
The intention was to find out whether or not we could get away with an unmodified oil system. The implications are two-fold. From a technical perspective, we can utilize more airflow on the other three heated fluids. From an ownership perspective, an unmodified oil system has less warranty implications.
We ran a total of 18 laps over 30 minutes, and did not de-rate once. Max speed at the end of the session matched the beginning.
However.
Fluid temps were through the roof. The OEM oil temperature sensor, as read by the ECU, will not read more than 302°F, or 150°C. You can see in the graphs below, the oil temps "plateaued" when temps reached 302°F. In all likelihood, they kept climbing a few degrees above that.
You can see in this IR picture the temperatures of the intercooler radiators match pretty closely, which is good. They're sharing the load well. It's also clear that the hood vent is far from cosmetic, and is radiating quite a bit of heat.
What does this mean for the average buyer?
In 96° weather, the car did not go into limp mode, or even de-rate significantly, with our intercooler and engine coolant package. Oil temps were NOT what we would consider acceptable for a dedicated track car, but for the average buyer, this may be a potential Stage 2 solution to accompany the supercharger intercooler system.
From here, we will address the engine oil cooler system and find a more production-friendly location.
Given your latest post, what I'm wondering is whether simply replacing the GM secondary radiator with an equivalent sized intercooler laid flat would be a better solution that doesn't require cutting up the bumper. That would include removing the current intercooler from in front of the main radiator thereby making it more effective as well.
Do you have any thoughts on this? I realize that level I'm stressing the system is far less than you but for guys like me that might be a better compromise.
Based on what we learned today, that won't be adequate. With only one intercooler radiator, intercooler temps got uncomfortably high for 80° weather.
Trust me, we REALLY don't want to run the "cheek" intercoolers, but keeping the car cool & safe is a higher priority.
2014 NASA Texas TT1 Champion
2015 NASA Texas ST1 Champion
2018 NASA TTU & TT3 National Champions
2019 NASA ST2 National Champion
2019 NASA Texas TT2 Champion
2020 SCCA Majors COTA GT2 pole sitter
2020 SCCA Trans Am Road Atlanta SGT Winner
2022 NASA National Champion ST2
2023 NASA National Champion ST2
2023 NASA National Champion TT2
Isn't this the same car and driver that has video posted on YT, doing super fast WSIR laps @ 1:30?
Been looking around for your car @ various local tracks when I run.....have some questions....
&
I'm thinking I can learn some things from running/following your lines......when is your next track day in that C5 beast?
Thanks.
Yes I've got a bunch of video on youtube, and do hit the local Socal tracks when I can get away...
I'm not a SCCA racer or anything, just club running, I've gone low1:32s...Not sure when I get out again, pretty soon though.
Here's a video from a little while back where I integrated the video from the Z06 that was following me, along with 2 views from my cameras.
Fluid temps were through the roof. The OEM oil temperature sensor, as read by the ECU, will not read more than 302°F, or 150°C. You can see in the graphs below, the oil temps "plateaued" when temps reached 302°F. In all likelihood, they kept climbing a few degrees above that.
What does this mean for the average buyer?
In 96° weather, the car did not go into limp mode, or even de-rate significantly, with our intercooler and engine coolant package. Oil temps were NOT what we would consider acceptable for a dedicated track car, but for the average buyer, this may be a potential Stage 2 solution to accompany the supercharger intercooler system.
From here, we will address the engine oil cooler system and find a more production-friendly location.
Jake[/QUOTE]
If I understand this correctly, you have the intercooler temps under control, ECT temps are great, and consistent timing, but the oil temps are in the 300 degree range with the stock EOC. I gotta ask, and I understand you have some serious engineers on this, but would the cat wraps and oil line wraps help any? Its been discussed and many have dismissed it. I am just curious and it would not take much to test this mod. the warranty implications for the oil cooling mod I think are significant. Great work!!!
I'd love to see a test done with the stock EOC and it's own dedicated cooling circuit. Separate pump and water to air heat exchanger. Pump controlled by oil temp (turns on at 180ish).
When driven hard, the stock EOC may not have the surface area required to show any gains in this configuration, even if it was supplied with coolant close to ambient temps. Be nice to find out though.
I'd love to see a test done with the stock EOC and it's own dedicated cooling circuit. Separate pump and water to air heat exchanger. Pump controlled by oil temp (turns on at 180ish).
When driven hard, the stock EOC may not have the surface area required to show any gains in this configuration, even if it was supplied with coolant close to ambient temps. Be nice to find out though.
As far as I know, you can't do this with the stock oil-water heat exchanger AND a dedicated air-oil radiator circuit. The method of doing an air-oil radiator circuit required removing the OEM water-oil heat exchanger.
Last edited by spearfish25; 07-16-2016 at 09:09 AM.
What I was trying to describe was a completely separate coolant circuit for the stock EOC. Stock EOC with a separate electric pump, coolant lines and air/coolant radiator.
Or, add another radiator to further cool the coolant after it leaves the block so that the coolant the stock EOC is supplied is at a lower temp.
Just curious to see if the stock EOC could keep the oil temps in check if it were supplied with lower temp coolant.
If I understand this correctly, you have the intercooler temps under control, ECT temps are great, and consistent timing, but the oil temps are in the 300 degree range with the stock EOC. I gotta ask, and I understand you have some serious engineers on this, but would the cat wraps and oil line wraps help any? Its been discussed and many have dismissed it. I am just curious and it would not take much to test this mod. the warranty implications for the oil cooling mod I think are significant. Great work!!!
It's an interesting idea. It might work, but it also might make such a slight difference it'd be hard to prove. A 1 or 2 degree change in oil temps could just as easily be attributed to environmental differences for that particular test. I don't see it dropping 10 degrees of the oil temps, you know?
I could be wrong, that's why we test. Maybe we'll try that out.
Originally Posted by CGZO6
What I was trying to describe was a completely separate coolant circuit for the stock EOC. Stock EOC with a separate electric pump, coolant lines and air/coolant radiator.
Or, add another radiator to further cool the coolant after it leaves the block so that the coolant the stock EOC is supplied is at a lower temp.
Just curious to see if the stock EOC could keep the oil temps in check if it were supplied with lower temp coolant.
Interesting idea. Not sure how we'd package that all in there. We'll have to think that one over. Thanks for the input.
Interesting idea. Not sure how we'd package that all in there. We'll have to think that one over. Thanks for the input.
Jake
The stock setup supplies the EOC with coolant from the left side of engine block (hot). I've wondered what would happen if the coolant supplied to the stock EOC was supplied with colder coolant. Is there a way to tap into the water pump to get coolant from the return side of radiator? Possibly the HVAC heater line? I don't know what the HVAC heater coolant flow is.
The stock setup supplies the EOC with coolant from the left side of engine block (hot). I've wondered what would happen if the coolant supplied to the stock EOC was supplied with colder coolant. Is there a way to tap into the water pump to get coolant from the return side of radiator? Possibly the HVAC heater line? I don't know what the HVAC heater coolant flow is.
It actually takes oil from the coldest point of he radiator, and returns it to the block.
Your proposal would require a third coolant system. Engine. Supercharger. Oil cooler.
It's a good idea, ford employs a similar methodology on some of their trucks.
07-15-2016, 06:28 PM
Maybe we'll try that out.