Max Oil Temp stayed flat at 262.4F (128C)

[OldRanger]

This data is from last weekend at VIR. Air Temps were in the upper 80s. Black line depicts oil temp maxing at 262.4F (128C) on lap 4-5. The blue line is water temp maxing at 200.7F on the bridge straight in lap 4 and 5.

What are you thoughts on why the Oil Temp would climb gradually for 4 laps...then taper...and the flatten out at 262.4? Why wouldn't it just keep creeping up on Lap 5?

Is that a magic number?

?

I have a new OEM Oil Cooler, 2 year old OEM Radiator. The A/C Condenser and Aux fan are removed.

[heinzboehmer]

Where did this data come from? 128 =2^7, so could be that whatever is storing/reporting your oil temps is only allocating 8 bits for the value (7 data bits, 1 sign bit and I guess for some reason offsetting it by 1?).

[OldRanger]

The data is coming from the CAN, captured in an Aim MxM, and displayed in Race Studio RS3

[bigjae46]

If I'm consistently shifting at 7.5k RPMs then that's about what I get to and won't go above for oil temps.

Where are you shifting at? I need to get lower oil temps when running to redline.

[OldRanger]

This is from my son's session. Looks like he shifts between 7,500 and 8,000 rather consistently. Some split second blips above 8k when shifting 3-to-4 and 4-5 a result of bad timing on the clutch pedal. Wwe have an Epic tune with 8,200 rev limit.

[Obioban]

I don't think it's a magical number, but...
-the greater the delta between air temp and engine oil temp, the more efficient the cooler is at cooling
-the higher the temp of the oil, the thinner it is, the less friction there is, the less heat is generated

Assuming your cooling system is sufficient, it makes sense for it to level out at some value.

[heinzboehmer]

The data is coming from the CAN, captured in an Aim MxM, and displayed in Race Studio RS3

Oh I actually didn't know this value was on CAN (gotta go update my data logging strategy now). Looked it up and it looks like it's a uint8 with an offset: https://www.ms4x.net/index.php?title...Bus#DME4_0x545

So yeah, no magic number. +1 to the "system is reaching equilibrium" theory.

[karter16]

Oh I actually didn't know this value was on CAN (gotta go update my data logging strategy now). Looked it up and it looks like it's a uint8 with an offset: https://www.ms4x.net/index.php?title...Bus#DME4_0x545

So yeah, no magic number. +1 to the "system is reaching equilibrium" theory.

Yup think you're on the money there - you can see in lap 4 that it's really flattened out and only just pushes to 128, think it's just an interesting co-incidence that it's maxing out at that value.

[heinzboehmer]

think it's just an interesting co-incidence that it's maxing out at that value.

Hard to switch out of work mode sometimes. Saw a power of 2 and immediately started coming up with potential causes for the "bug"

[karter16]

Hard to switch out of work mode sometimes. Saw a power of 2 and immediately started coming up with potential causes for the "bug"

Ha not just you - as soon as I saw it I double checked the disassembly


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