If you doubt Tesla's engineering then you need to watch this
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Because the radial force is proportional to the square of the velocity, there is giant difference between the force on materials at 12K and 18K spin speed. Any casting or machined metal in the Tesla would have to be flawless internally.
As for turbochargers, gas vehicles have oil pumps to supply lubricant to everything needing it, an electric car doesn't. At 18K, ball bearings would need forced lubrication, as the centrifugal force would strip them of lube very soon. At Garrett Airesearch we had to run a high speed rotor in a vacuum with magnetic bearings because a metal one could not last at these high speeds. That is why I'm impressed with the Tesla motor design.
Model S Plaid motor: https://www.youtube.com/watch?v=Ci4qiHJvMEw
Only rotor. And that is not that hard.
Or you should use sealed ball bearings. Also, centrifugal force for bearing much less that for the rotor, since diameter of rotating parts is much smaller. Vaccum cleaner turbines runs at 20-30K RPM, and ball bearings perfecly OK without forced lubrication for many years. SKF gives limiting speed for randomly taken W628/8-2Z bearing at 45K RPM f.e.
I had the wrong model. I was envisioning the rotor running in a planetary outer bearing race but with the hub connected to the wheel. But that's wrong because it couldn't be direct drive, the wheel does not turn at 18K rpm of course. I'm going to have to go research the per-wheel drive train.
It's a bad idea to put huge mass of motor into the wheel. You should keep unsprung mass as low as possible. AFAIK, Teslas have usual wheels with CV joint ended semiaxles connected to differential - reduction gear - motor assembly. That assembly looks like letter T, where top bar ends is a motor and reductor and vertical bas is differential. Nice and simple design, but everything is totally ruined by unsing highly ineffective and insane expensive chemical battery with ridiculously low energy density as power source for that nice drivetrain, making all thing senseless. Electric passenger cars have no future unless normal power source will be invented.
Yes. I had just researched the motor-to-wheel connection, which looks a bit weird but now I see there is a simple fixed gear reduction in the housings. Instead of the complex mechanism in a gas vehicle transmission, the speed reduction from the electric motor is handled by simple fixed gears and computer control of the motor speed.
Now as for the power, we are still waiting for Doc Brown to release the Mr Fusion powerplant to use instead of batteries.