You sir, are a gentleman and a scholar. Thank you for imparting your perspective for the group.
Car wow pitted the Model 3 dual motor vs a Model 3 performance and although the performance was walking it up to the 1/4 the dual motor caught it and passed it at some point consistently. This reeks of the same thing but obviously worse.
FYI this was fixed in an update late winter 2021. The heat pump 2021 Model 3 was scavenging heat from the battery pack, lowering power output. They used an older Model 3 with the PTC heaters. Another race would show different results.
Yeah, I just caught that - one’s red, one’s blue. Still, if this car is biased for 0-60, it isn’t even hitting Ford’s claim. There is either something weird going on in settings, or Ford has a massive problem going forward. A long range Y will do about as well to 60 and keep pulling.
Back in the day, they called the “open days” “Grudge Nights.” Run what you brung, if it passes tech. I have only run at NHRA sanctioned tracks, so part of the tech was to make sure sub-14 second cars had roll bars and sub-13 second cars had cages, in addition to making sure you had a puke can, no leaks, and nothing obviously broken.
With more GTPE now ending up in owners hands there will be more data to go on so it probably wont take that long to see what the actual performance is and if this is just a one off.
The problem with this postulation is the GT has a 9-point-something to 1 gear and the other AWDs have a 10-point-something to 1 gear in the front motor. It would be spinning more RPM at the same speed so there would be more power drop-off for the AWD front motor.
This is really cool - thanks for doing this and for sharing the numbers!
I actually have one of the early REMY HVH250 motors, but have never had an inverter tune to run it. Some PM motors do have this much fall-off in power at higher speeds, but most do not. There is usually some fall off in power as top motor speed is approached, but a constant power approximation above base speed is usually pretty good. Look up CPSR (constant power speed ratio). This data does show how important battery supply voltage is for motor base speed and transition from constant torque to constant power.¡Viva México, hermanos! I learned a lot about power electronics from a good man from Puebla, so here are some more thoughts on power and voltage.
I think that the graphs you show are probably pretty close in scale and shape to the motors in the MachE. The absolute values are certainly off some, but you are looking at a graph for the same design of motor from the same manufacturer in a similar iDM, so the "shape" is probably representative.
From this, we can tell that power is roughly proportional to voltage (over the constant torque range), and that power at 12kRPM is about 65% of the peak power. Pushing out a bit further to 13.8k RPM you're probably looking at about 55% of peak power.
This makes the voltage point well - I took some measurements on my Premium AWD ER (more detail here: https://www.macheforum.com/site/threads/driving-dynamics-and-charging-data-files.8473/page-2) and it looks like the resting battery voltage is about 387V at 100% SOC, and about 360V at 72% SOC. I also measured an internal resistance of 35.5 mOhms, which you can use to calculate voltage drop at different powers.
So by charging to 100% you'd have about 8% more power to work with, compared to 72%, or about 36hp peak. That isn't enough to explain the trap speed, but it would certainly help. Voltage drop under sustained high power will bleed more off too. At full power the car should be pulling close to 1000A, which would see a voltage drop of about 35 volts, or almost 10%.
I'm looking forward to seeing some more runs with voltage and current data recorded, it should give us a better idea of when things are limiting and why.
