Originally Posted By: A_Harman
Originally Posted By: Cujet
As for 1/4 mile runs, the Model S can do plenty of them at the local strip. It's track days that cause the higher temperatures which result in current limiting. And, it's absolutely not a track-day car. It's a hard-accelerating, electric, heavy, family car.
Again, it's not designed or engineered for track days. The temptation is to compare the Tesla to some of the worlds best sports cars, because of it's acceleration. That's a foolish comparison. You would not take a Chevy Impala on the track and then complain about it's lack of prowess. Yet, it's in the same category of family car, price notwithstanding.
When Tesla comes out with a "Track-Pack" version, then the comparison is valid.
You talk about the hypothetical "Track-Pack" Tesla as if it's just a matter of bolting on a few coolers, then it'll be good to go for 2-3 hours a day like the hydrocarbon fueled cars. It isn't that easy. The battery pack would have to be completely redesigned to effectively cool the hundreds of cells to keep them in an efficient range of operating temperature. Making more room in the battery pack for coolant passages will reduce the number of cells that can be put into the available volume. This will reduce the energy storage capacity of the battery pack, so what used to be 85 or 90 kW*hr becomes more like 55 or 60. Then it also becomes important to add water cooling to the motor core and the power control electronics, which adds more to the weight of the car. Plus the radiator must be sized very large to keep the regulated coolant temperature to about 140F, because above that, the internal resistances of all electrical components becomes so high that the powerplant efficiency drops.
That's exactly right, the engineering involved in making electric cars track capable is daunting. The Model S is a 5-7 passenger car, not designed for track days. Expecting it to perform on the track is improper. At the moment electric propulsion is exceedingly expensive, and of limited capability.
Even so, Tesla has achieved remarkable acceleration performance from a 5000 pound family car.