06-13-2021, 08:51 PM | #1 |
Drives: 2020 ZLE A10, 2018 F250 Diesel Join Date: Apr 2020
Location: Atlanta
Posts: 148
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Heat Soaking on Track
Just curious if others have experienced heat soaking and power loss of the track when it’s very hot out. I was running the car as hard as I could this weekend and noticed that I was definitely down on top end speed by about 20mph or so. I typically see high 140-150 on this straight, but could only manage about 130-135 this weekend.
Now it was very hot with track temps around 98 degrees. Only change to the car this time vs last, was I did add a rotofab intake (standard, not big gulp). So was the car just pulling that much timing that it was way down on power or is it possibly related to the intake. Car is stock with no tune. If this is common, what are you guys doing to help with the heat on track? |
06-14-2021, 07:10 AM | #2 |
Drives: 2017 Camaro SS, 2011 Corvette GS Join Date: Feb 2019
Location: Erlanger, Kentucky 41018
Posts: 815
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Likely, your intake air temps were very high. Likely over 150F or more. So car will be pulling timing and have reduced power.
I can remember the exact number but I think on 4th gen LS motors (LS3, LS9, LS7, etc.) the ECM pulls timing when IAT's get to 125 or 130. Likely the same or similar for LT1, LT4. May be time for some cooling mods for your car; bigger supercharger radiator, larger reservoir tank, etc. On my C6 Corvette, I have an E-force supercharger. I added a larger intercooler radiator, much larger Cordes Performance reservoir, spacer plates and heat insulation between the supercharger and engine, and I upgraded the radiator to a DeWitts. All of this keeps my IAT's much lower than before and the temps recover much faster after a run. |
06-14-2021, 10:48 AM | #3 | |
Drives: 1LEs Join Date: May 2009
Location: DFW - Texas
Posts: 1,319
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06-14-2021, 11:38 AM | #4 |
aka BeastZL1
Drives: 2019 Camaro ZL1 1LE, 2004 Cobra Join Date: Dec 2017
Location: NC
Posts: 1,103
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Heat Soaking on Track
You can expect 5-7 mph drop on long straights in high ambients.
You can help reduce the impact by: 1. Katech 172 F thermostat 2. Reduce the glycol percentage in the radiator and intercooler 3. Add redline water wetter Sent from my iPhone using Tapatalk Pro
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06-14-2021, 12:15 PM | #5 |
Drives: 2020 ZLE A10, 2018 F250 Diesel Join Date: Apr 2020
Location: Atlanta
Posts: 148
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Thanks. I was doing some reading and went ahead and ordered the ADM reservoir kit. I’m thinking high heat and possibly some air in the intercooler or something. Probably a good start.
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07-06-2021, 03:34 PM | #6 |
Drives: 2021 ZL1 1LE Join Date: Aug 2010
Location: Fredericksburg, Virginia
Posts: 409
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I was at VIR a couple weeks ago with Chin. Temp outside was around 90 degrees on Monday. Around the 30 minute mark car started pulling power on the back straight. Wouldn't go over 130mph. Oil temp was around 270 degrees as well.
Let the car cool down and had no more issues remaining of the day. |
07-06-2021, 07:34 PM | #7 |
Drives: 2020 Zl1 A10 Riverside Blue Join Date: Mar 2020
Location: NJ
Posts: 1,219
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What was your coolant temp?
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07-07-2021, 06:04 AM | #8 |
Drives: 2021 ZL1 1LE Join Date: Aug 2010
Location: Fredericksburg, Virginia
Posts: 409
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07-07-2021, 11:14 AM | #9 |
aka BeastZL1
Drives: 2019 Camaro ZL1 1LE, 2004 Cobra Join Date: Dec 2017
Location: NC
Posts: 1,103
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I would check this on the PDR with Cosworth toolbox or an OBD2 reader. The on-dash display is notoriously wrong.
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07-07-2021, 01:33 PM | #10 |
Thank you Al Oppenheiser!
Drives: Red Hot A10 ZL1 Convertible Join Date: Jun 2017
Location: Sarasota, FL
Posts: 4,973
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Check and bleed the supercharger intercooler loop. Might have air pocket which will cavitate down the pump, triggering pump-safety-shutdown and raise AITs, causing the behavior you describe.
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07-08-2021, 05:56 PM | #11 |
Drives: 2020 Zl1 A10 Riverside Blue Join Date: Mar 2020
Location: NJ
Posts: 1,219
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07-08-2021, 07:15 PM | #12 | |
aka BeastZL1
Drives: 2019 Camaro ZL1 1LE, 2004 Cobra Join Date: Dec 2017
Location: NC
Posts: 1,103
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Quote:
220+ F is normal under track conditions per OBD2 gauge or the vehicle health tab in the Cosworth Toolbox. The factory dash gauge might as well be an on/off switch.
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07-15-2021, 12:38 PM | #13 |
Drives: 2020 ZLE A10, 2018 F250 Diesel Join Date: Apr 2020
Location: Atlanta
Posts: 148
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Yes I added the reservoir which should fix that. After the install, it sucked down a good bit of coolant, so more than likely that was the issue. The car feels like it picked up a bunch of power post install.
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07-15-2021, 01:47 PM | #14 | |||
Drives: 2017 SS 1LE, 2016 1SS (previous) Join Date: Apr 2016
Location: Metro-Detroit
Posts: 1,863
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Quote:
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I don't have a lower temp T-stat yet, so I haven't data logged this, but I'm willing to bet there is something there. How much is the question, but if there is -10F, that's a worthy change! Oil temps of 155-165F are better than 165-170F. Quote:
In my SS 1LE, I've never seen my coolant go beyond 220F. In fact, 99.99999% time it wont eclipse 217F. Last edited by Mountain; 07-15-2021 at 01:59 PM. |
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