Tri Motor Cybertruck HP?

ajdelange

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Pretty simple to say all these numbers people are giving out on Horsepower of the CT are educated guesses.
Let's try to take some of the guesses out. Sixty mph is 26.82 m/s. If the CT accelerates uniformly from 0 to 60 in 2.9 seconds that 26.82/2.9 = 9.25 m/s/s (0.94g). Now we have to guess at the weight. Using 5500 lbs that means mass of 2500 kg. The power required to accelerate 2500 kg at 0.94g from 60 mph is P = m*v*a = 2500*26.82*9.25 =620212 joules/sec (watts). One horsepower is 735.5 watts. Dividing by that gives 843 horsepower. Now that's the power required to accelerate the mass. At 60 mph there is, of course, substantial drag and also rolling resistance, drive train and slip loss to overcome so the motors will have to deliver somewhat more than 843 hp. So now we are back to some guesswork. Assuming the frontal area to be 4 m^2, Cd = 0.4 and air density to be 1.225 kg/m^2 the drag power load would be 1.225*26.82^3*0.4*4/2 = 18906 Watts equivalent to another 25.7 hp. Drag would be the major load after the inertial one and so allocating 32 hp to all of them is probably reasonable. This brings the estimate to 843 + 32 = 875 hp distributed over the three motors. If equally apportioned that would be 292 hp each.

This estimate is based on what it would take to meet the stated 0 - 60 requirement which is, I assume, the most stringent power requirement placed on the motors. The big assumption underlying it is that the motors' power limited regions start at 60 mph (given the huge significance attached to 0 - 60 times in the automotive industry). I don't think that's an unreasonable assumption and I'll stand by 875 or so until I hear differently from someone like Sandy Munroe. All the other numbers are, as the quote says, either guesses or marketing hype.
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Ehninger1212

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Tesla mayalso select one or more motors that are larger than the ones used in their smaller cars. Because the truck will expect to be under heavy load for longer, and it has more space tomadd bulk to cool.

Changing the coils in a motor gives it different capabilities.

I expect the design to be shared with the Plaid models, but the motors to actually not be the same exact ones.

-Crissa
Precisely! This method has been applied to vehicles for decades. For example, a 5.0 Mustang ICE is the same basic engine as the F-150 5.0 ICE. But ford changes aspects of those ICE's based on the intended use such as intake manifolds, cam shafts, exhaust manifolds injectors ect..
 

ldjessee

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It would be interesting if the Semi and the CyberTruck share motors... Since towing and performing under load is something they both will be expected to do.
 

ajdelange

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There is certainly powerful motivations for them to share parts if it is possible and if it is I expect they will. I'm not at all sure at this point that the rear and front motors will be the same in the CT nor am I sure that all the motors in the Semi will be the same. But I wouldn't be surprised if there were some parts commonality.
 

T3slaDad

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It would be interesting if the Semi and the CyberTruck share motors... Since towing and performing under load is something they both will be expected to do.
The semi just uses 4x M3 motors, so nothing special there (except the fact that the M3 motor truly is revolutionary in its design).

Fun Fact: do you know where the M3 motor came from originally? It was used as an actuator motor on SpaceX rockets, then they decided it would make good use as a vehicle motor and BAM! Here we are.
 

ajdelange

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The semi just uses 4x M3 motors, so nothing special there (except the fact that the M3 motor truly is revolutionary in its design).
There may be some clever twists unique to Tesla's implementation but it is hardly anything revolutionary. It's a permanent magnet assisted synchronous reluctance motor, or, if you prefer an interior permanent magnet motor.[/QUOTE]
 

ldjessee

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Look at the changes to the Model 3 motor to the Model Y. Improvements already... so I think that even if the original plan was to have Model 3 motors for the Semi, it does not mean they are there now.

Remember, Model Y and 3 were supposed to share a high percentage of parts, but turns out they do not...
 

Crissa

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Remember, Model Y and 3 were supposed to share a high percentage of parts, but turns out they do not...
Well, they still do. And the parts that are different just showed up in the Model 3 refresh.

It's always easier to put the newest parts in the model you just introduced. It makes for fewer documentation changes, lets you use up parts in production streams that are already functioning. And makes sure your delays are synergistic instead of antagonistic: If you're already waiting for part A might as well also order B and C so they'll arrive at the same time.

-Crissa
 

ajdelange

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I spent 12 minutes watching that to find out that the watt is a more sensible unit for power than the horsepower? I wonder if he has another one explaining that the meter is a more sensible unit of length than the distance from Henry's nose to his thumb.
 
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