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S550 Engine Coolant Over-Temp after hard braking

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23
4
Exp. Type
HPDE
Exp. Level
Under 3 Years
Lubbock
At a track day at ECR, I expected heat to be an issue, but not in the way it presented... Everything seemed hot but fine.

When braking (1G+) after a long straight, I would see the coolant temp jump and throw an alert. After coasting around at 50% for a few corners, it would jump back down like 40 degrees.. There was no steady rise or drop. I'm not sure if this is due to polling, oil starvation or something else?

Is the coolant temp directly measured or is it implied through cylinder head temp?

Any insight or diagnostic suggestions would be appreciated.
 
23
4
Exp. Type
HPDE
Exp. Level
Under 3 Years
Lubbock
You likely saw the "Lag" in heat produced by the engine on that long straight. The heat came from the long run on the straight but did not "Soak Through" until you were braking.

Ah, okay. Would the sudden drop after a few corners also fit that theory?

I plan on getting an oil cooler and trans cooler before the next outing. I just wanted to make sure it wasn't oil scavenging issues starving the engine.

Thanks
 

TMSBOSS

Spending my pension on car parts and track fees.
7,529
5,243
Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
No worries.
BTW, Welcome to the site. I missed that the first time. Sorry.
Yep, if the on throttle time before the next few corners is less, temps could fall.
If you could add a "Vehicle Profile" it would assist other members in making recommendations for mods.
Yes, cooling is almost always a good choice assuming your ride is nearly stock. Don't overlook safety and drivers mods also.
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
4,008
1,924
Exp. Type
W2W Racing
Exp. Level
10-20 Years
Cookeville TN
Temperatures for Coyote based engines are directly related to RPM and duration. The S550 calculates oil temp based on the CHT sensor, RPM, duration of RPM, fuel flow, load and other parameters. It does a good job but is very conservative. I run an actual Autometer Gauge for oil temps and see typically a 20 degree delta from the cars' inferred temp. For example the car will register "warm" oil temp after about 20 minutes of running using 7800 as a max RPM with typical 7500-7700 shift points, this correlates to 283 DegF, my Autometer will be at 265 DegF at this time. So yes after a long WOT straight above 6000 rpm and alot of 3rd gear running you can see elevated temp warnings with corresponding power reductions, After some lighter load corners the temps do recover pretty rapidly. What configuration is you car? Cooling mods? Oil cooler?
 
23
4
Exp. Type
HPDE
Exp. Level
Under 3 Years
Lubbock
Temperatures for Coyote based engines are directly related to RPM and duration. The S550 calculates oil temp based on the CHT sensor, RPM, duration of RPM, fuel flow, load and other parameters. It does a good job but is very conservative. I run an actual Autometer Gauge for oil temps and see typically a 20 degree delta from the cars' inferred temp. For example the car will register "warm" oil temp after about 20 minutes of running using 7800 as a max RPM with typical 7500-7700 shift points, this correlates to 283 DegF, my Autometer will be at 265 DegF at this time. So yes after a long WOT straight above 6000 rpm and alot of 3rd gear running you can see elevated temp warnings with corresponding power reductions, After some lighter load corners the temps do recover pretty rapidly. What configuration is you car? Cooling mods? Oil cooler?

I added my plans to my profile but if you have suggestions for coolers I’m all ears. All that I have done is suspension/chassis upgrades and a Lund tune.

I also plan on data logging my event next time because I’m assuming there was lag on the screen too. I’ve seen stuff like AFR lock up for a second on the gauges screen, but never in my software.
 

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