[Olphart]

the model 3 drive unit has enormous cooling capacity, what with a head exchanger and an oil pump that spins faster as the motor gets hotter

the model S' large rear motor, by comparison, just has a gear driven oil pump that's dictated by wheel speed and no proper heat exchanger, which is why the model s famously couldn't do more than a few laps on a track before going into limp mode.

has anyone tried to fix this though? possibly adding an external oil pump with heat exchanger inline with the rest of the system. It doesn't need MUCH extra cooling, just some extra cooling

You have me curious so I will comment to follow your thread and maybe learn how wrong I am.



My impression is that the gear housing is the only oil in the drive assembly. While supplemental oil cooling that may help, I'm guessing it doesn't directly pull heat from the motor windings??



Perhaps a larger radiator combined with a storage tank to increase coolant capacity would do it?

 

[brian_]

Cooling and lubrication of the Model S/X drive units has been discussed previously in this forum... I suggest doing some searching. Without rehashing those discussions, I'll just note the that the "small" drive units (front, and rear of the non-Performance AWD variants) are substantially different from the "large" drive units (rear of 2WD and Performance AWD variants) in cooling design. It's important to understand which one you are considering.

 

[joekitch]

Cooling and lubrication of the Model S/X drive units has been discussed previously in this forum... I suggest doing some searching. Without rehashing those discussions, I'll just note the that the "small" drive units (front, and rear of the non-Performance AWD variants) are substantially different from the "large" drive units (rear of 2WD and Performance AWD variants) in cooling design. It's important to understand which one you are considering.

it's been discussed somewhat but almost all within one thread for the cobra race car
https://www.diyelectriccar.com/forums/showpost.php?p=990721&postcount=25
the mod by the skyline guy which splits the inverter and motor cooling apart is very interesting though