The simplest explanation is that the model 3 has a new(ish) type of motor, and they felt in order to avoid torque ripple they needed to modulate the launch. This is all speculation, but I like narrowing things down to changed variables. If the model 3 RWD has a similarly languid launch, then there's more evidence that the switched reluctance permanent magnet motor needs to be launched less aggressively, and the induction motor in front does most of the heavy lifitng. I'll let the internet engineers chime in.
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P3D+ Acceleration
- Thread starter kbecks13
- Start date
You may be on to something, but the other way around. The PMSR is phase locked to the drive signals/ commutation. Whereas the AC Induction has the rotor slip factor to contend with. As a result, the control of the AC type is less precise in term of torque control (torque ties to speed in the AC motor, whereas they are directly separately measurable/ controllable in the PMSR). Thus the launch control waveform may be super aggressive on the S/X.
So the new behavior may be intentional from a passenger/ driver comfort point of view.
Ripple would exist at any high torque operating point albeit at a different frequency.
It needs that front motor to pull it. IMO. Part of it is that you don't feel the weight transfer as much as a RWD.
It is physics. From rest, much of a car's power is consumed in getting the car moving to overcome static friction. Once this static friction has been overcome more energy is available to accelerate the car.
See Friction - Wikipedia - checkout diagram in static friction section
See Friction - Wikipedia - checkout diagram in static friction section
What are you referring to?
The hubs and gears all have ball or needle bearing, so I don't know of any static friction locations.
Are you thinking of inertia?
Daniel in SD
(supervised)
Uhm. I can push a car with my bare hands on a flat surface. Unless you've got the brakes on there isn't a whole lot of static friction.
Daniel in SD
(supervised)
Weight transfer is independent of the drive wheels. That's why RWD cars can accelerate faster than FWD cars, the weight transfers to the drive wheels instead of off of them.
I think @Nocturnal may have meant chassis dynamics (though they said weight transfer) The more the front motor is doing, the less rear wheel torque to lift the front end. To the extreme that you can't pop a (normal) wheelie in a front wheel drive car.
Daniel in SD
(supervised)
You can't pop a wheelie on a front wheel drive car because you'll lose traction. Equal weight distribution, suspension stiffness, and acceleration the weight transfer to the rear of the car will be identical.
Weight transfer - Wikipedia
forkee
Member
i tested brake hold and slip start and it made no noticeable (at least advantageous) difference.
from my other thread...
Yes, I get that. I'm saying the feel of a rear wheel launch is partly due to the front of the car rising. Weight transfer requires acceleration, rotating the chassis can be done at a standstill (depending on tire stickyness). Rear wheel torque reaction, not mass versus CG height.
Sure you can.
Thanks, now I feel justified adding the clause to my statement
I beg do differ. I own both.
The quote I responded to was comparing M3P and MSP85 (see above). That's what I was disagreeing with.
Regarding P85D...
"How": Drive them back to back.
Oh, you probably mean what is my evaluation.
M3P feels somewhere between* P85D (Insane) and P85D (Ludicrous) in a straight line. Our P100D is a whole different level.
As for performance "with turning involved" and "with stamina involved", the M3P is much better than any S offering I've driven.
* Point of clarification: My gut reaction (literally) was identical in this regard to my co-pilot. She (physically) hates what the P100D [Illyria] does to her breathing, was "ok" with P85D (Insane) [Mercury @ delivery] and "uncomfortable" with P85D (Ludicrous) [Mercury @ post-op]. She loves riding and driving the M3P [Beatrice] -- with no required "human governing" of throttle use. In fact, it's the first time she's giggled in a Tesla since the P85 [TesS]. Happier household.
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If you think about it, the P3 might feel slow off the line because it's the smoothest power band ever. According to some Dragy data out there, It takes .5s to go 0-10, 1s to go 0-20, 1.5s to go 0-30, 2.1s to go 0-40, 2.7s to go 0-50, 3.5s to go 0-60. 30-50 time is 1.3s. If those numbers are accurate, then I think it's just the way we're perceiving the power.
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