Tesla has announced that it is starting the rollout of Track Mode, a feature of the Model 3 Performance that allows the car to perform better on a racecourse, today. In light of the feature’s release, Tesla has published a blog post outlining the science behind Track Mode, as well as the feature’s specifics.
While Tesla’s other performance-oriented upgrades like Ludicrous Mode for the Model S and X help a vehicle with straight-line acceleration, Track Mode helps the company’s electric cars handle corners better. Tesla’s blog post notes that Track Mode was designed specifically to be used on closed autocross circuits and racetracks. The company also pointed out that its goal behind the development of Track Mode was simple — they wanted to use the power of the vehicle’s electric motor and instant torque to “make cornering on the track feel just as natural as forward acceleration.”
Track Mode enables vehicles to precisely control whether torque goes to the front or the rear wheels. This allows the Model 3 Performance to instantly increase or decrease the car’s rotation in a corner. With such a system in place, racing enthusiasts would find that highly technical driving sessions on a closed circuit would be a lot easier.
Unlike the usual Sport Modes of legacy carmakers, which usually involve the disabling of stability control, the Model 3 Performance’s Track Mode adds features to the vehicle. Tesla accomplished this by replacing the electric car’s stability control system with its own Vehicle Dynamics Controller — a software specifically developed for the company’s electric vehicles that acts as both a stability control system and a performance enhancement on the track. Tesla also provided a summary of the features that are employed by Track Mode when it is activated.
Motor Torque for Rotation
Our Vehicle Dynamics Controller continually monitors the state of the vehicle and all of the inputs from the driver to determine the driver’s intention and affect the rotation of the car in a matter of milliseconds. Track Mode relies heavily on the front and rear motors to control the car’s rotation, and we have the ability to command a 100% torque bias. When cornering, if rotation is insufficient to the driver’s request, the system controls a rear biased torque. Conversely, when rotation is excessive, we command a front biased torque.
Increased Regenerative Braking
Heavy regenerative braking may not be comfortable for day-to-day driving, but on a track, it has several key advantages. It gives the driver more authority with a single pedal, improves the endurance of the braking system, and sends more energy back into the battery, maximizing the battery’s ability to deliver large amounts of power. It also gives the Vehicle Dynamics Controller more authority to create or arrest rotation with the motors when your foot is lifted off of the accelerator pedal.
Track Focused Powertrain Cooling
The high output power required for track driving generates a lot of heat, so endurance on the track requires more aggressive cooling of the powertrain. We proactively drop the temperatures of the battery and the drive units in preparation for the track and continue to cool them down in between drive sessions. We can also allow operation of the powertrain beyond typical thermal limits and increase our refrigerant system capacity by overclocking the AC compressor into higher speed ranges.
Enhanced Cornering Power
We typically think of using brakes to slow down a car, but you can actually use them to make the car faster out of a corner. All Model 3s are equipped with open differentials, which send an equal amount of torque from the motors to both the left and right wheels. When cornering, the wheels on the inside of the corner have less load on them, which means they can provide less tractive force than the outside wheels. To prevent excess slip on this inside tire, we have to limit the torque for both wheels, leaving power on the table. In Track Mode, we simultaneously apply brake and motor torque to produce a net increase in tractive force while cornering. This is similar to how a limited slip differential works, except when using the brakes, the differential can be optimized for various driving conditions.
What is particularly exciting about the release of Track Mode is the fact that it is just the first version of the system. On its blog post, Tesla noted that Track Mode is set to improve further in the future through over-the-air updates.
When Elon Musk announced the Model 3 Performance on Twitter, he noted that the vehicle would be around 15% faster than a BMW M3 on the track. Considering the pedigree of the German-made performance sedan as well as the tendency of Tesla’s previous vehicles to throttle their performance on a track, Musk’s claims were met with a notable degree of skepticism from both avid car enthusiasts and critics alike. That said, initial reviews of the feature were notably positive.
Tesla conquered the drag strip with Ludicrous Mode. It remains to be seen if the company can do the same on the closed circuit with Track Mode. Considering the deliberate design of the feature, though, there is a pretty good chance that the Model 3 Performance would soon be just as formidable on the track as the Model S P100D is on the drag strip.