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Raven (non-performance) Maximum Power Output vs 100D
- Thread starter DavidO
- Start date
A modern electric motor typically has a torque limit and a power limit - normally it puts out a fairly constant torque until it hits the power limit, and a slowly declining nearly constant power above that limit.
Most Teslas hit the power limits in the 50 mph neighborhood...
I do not have a Dragy unit but PowerTools provides speed directly from the vehicle together with a time stamp. I need to repeat my 0-60 run when I get a chance to get an accurate new 0-60 time but suffice to say my car was barely faster than a dual motor long range Model 3 carrying about 250 lbs more in a side-by-side drag race over the weekend. PowerTools did not work for that run. My SOC was slightly higher 83 vs 80. I sensed three stages to the run. There was some front wheel spin from the Raven initially, then I caught up and then the Model 3 accelerated just as fast while I was pulling away steadily at an estimated (from the video) 2 mph.
Agreed, but my understanding is that the majority of the power during hard acceleration is coming from the rear unit so the overall efficiency gains would be reduced by a certain amount. Does anyone know the new torque ratio with the latest software update? If we knew that, I could more accurately compare Raven and Non-Raven power values to determine any differences.
I'm not sure there's an assigned ratio at maximum acceleration - I'm thinking it's "everything the motors can put out" or perhaps "everything the tires can take."
Here you can see that a Ludicrous Raven S peaks at 360 kW rear and 177.5 front:
Here's a pre-Raven P100DL for comparison:
The rear motor hits the same 360 kW peak, and the front eventually hits 173 - but during the 0-60 phase where the 575 kW peak power hits it's down around 150kW instead.
The Raven is only showing a couple more peak battery kW, but the combined motor numbers in the 40-70 mph range are a good 20 kW higher, all in the front motor. Not sure what to make of that - less loss going to the motors, maybe?
My goal in this quest was to compare the motor outputs, and for Ludicrous cars the peak on the rear is exactly the same, while the new front motor puts out a few percent more than the old one. I would expect the Long Range will be similar...
SucreTease
Teslarian
As @Saghost has pointed out, I was mistaken in what I said.
Power put out by the vehicle produces two effects: (1) acceleration of the vehicle, and (2) overcoming friction (primarily drag, which increases with the square of the speed). I was only discussing the portion which goes into (2) and forgetting the portion which goes into (1). The some of these two is the total vehicle power produced, which reaches its maximum, as @Saghost pointed out, around 50 mph.
It's a little embarrassing for me to have temporarily overlooked this, considering that I wrote some theory on the torque and power relationship for acceleration profiles (where drag is less significant and I intentionally ignored (2)) in the Tesla Physics thread.
Powetools is measuring kw directly off the battery. If you display power, it simply multiplies it by 1.341.
I was able to record a 0-60 hard acceleration run this morning after installing 2019.32.1 last night.
Below is the graph generated from this morning's PowerTools file followed by the 100D result. Exact same section of road. Peak power today was 489HP @ 54 MPH vs 533 HP @ 60% from the 100D. What's noticeable to me are the high 10 and 19 mph data points, indicating tire slippage, since PowerTools draws it's speed data from the rotational speed of the wheels as opposed to GPS - slippage that I did not see in my 100D. Could this be due to new, better rolling resistance tires, hence Tesla's attempt at improving "driving dynamics during hard acceleration" in their latest software update? Has anyone else noticed this? Do Performance Ravens see this? Acceleration between 40 and 60 mph for my non-Raven looks and indeed felt faster.
Below is the graph generated from this morning's PowerTools file followed by the 100D result. Exact same section of road. Peak power today was 489HP @ 54 MPH vs 533 HP @ 60% from the 100D. What's noticeable to me are the high 10 and 19 mph data points, indicating tire slippage, since PowerTools draws it's speed data from the rotational speed of the wheels as opposed to GPS - slippage that I did not see in my 100D. Could this be due to new, better rolling resistance tires, hence Tesla's attempt at improving "driving dynamics during hard acceleration" in their latest software update? Has anyone else noticed this? Do Performance Ravens see this? Acceleration between 40 and 60 mph for my non-Raven looks and indeed felt faster.
SucreTease
Teslarian
Do you have something to substantiate this claim? It does not fit with what I think that I know.
Lhshockey24
Member
I think I mentioned earlier in this thread that I’m noticing tires slipping at 0-5mph and again later on (Raven Long Range). I don’t feel like spending the money on new tires, but when I ran Pilot Sport A/S3s on my P3D I never noticed a slip.
Here are the 100D and Raven PowerTools graphs overlaid. The tire slip is quite evident from the graph at low speeds. Without it I believe that the car now could accelerate faster than the 2018 100D. Perhaps the new tires are compromising grip for range. Could a front/rear torque ratio fix this. Also, the suspension was not set to low. Blue is 100D and red is Raven. 100D was at a lower SOC and lower ambient temperature but on exactly the same section of road (see earlier posts).
Attachments
Service Center acknowledges there is a problem with my car (could this be a Raven-wide issue?) and has escalated the case to Engineering. I'll update everyone when I learn more if it's resolved through updates. I'm really curious to know if any others are experiencing severe loss of traction immediately upon hard acceleration.
Lhshockey24
Member
Lhshockey24
Member
That’s great news! 32.2.1 hasn’t been pushed to my car yet. Can’t wait to try. I’m traveling so won’t be able to confirm it works for me too before the end of the week.
He just means the speed is what the car reports through the REST API rather than using the GPS of the iOS device which wifi ipads don't even have.
Yes, indeed. I think this data is, according to the following thread, most likely from rotation sensors with GPS-based correction over time to adjust for tire wear etc: Speedometer accuracy | Tesla
On the other hand, my son’s Model 3 was consistently disagreeing with GPS after 6 months of ownership whereas my S was always spot on.
I’m seeing momentary increases in indicated speed from PowerTools data during initial acceleration which apparently is related to tire slip. My 100D, which didn’t experience this traction problem, never showed these high “speed” data points. I don’t think it would be as pronounced if the data was from GPS.
Installed 2019.32.2.2 and the tire slip has apparently vanished but acceleration 0-60 has not improved. The graph generated in Excel from PowerTools data appears to show a 0-60 time between 3.85 and 3.9 seconds (slower than my 100D). I tested on a different section of road. Not sure exactly how flat it is. Max power occurs at 384 kW @ 44 mph.
