Interesting info. on GT3 Sport Chrono function
"The basic functions are the same as the current 911 generation,
allowing increased sportiness and even more direct responsiveness to
be achieved for the purpose of enhancing vehicle agility.
However, pressing the "Sport" button not only selects a sportier
performance, but also activates an engine map with enhanced torque and
power output.
When the "Sport" button is pressed, this increases the engine torque
by up to 18 ft lbs (25 Nm) in the mid-rpm range and selects a sporty
tuning for traction control (TC).
In the sports setting, the exhaust backpressure in the variable
exhaust system is reduced, the gas cycle improved and the torque
noticeably increased in the rpm range between approx. 3,000 and 4,200
rpm. This leads to an increase in the torque values of between 15 and
18 lbs (20 and 25 Nm) and an increase in the power output of 13 bhp."