Give you different torque, speed and acceleration....
6T greater torque, slower speed; 9T less torque, higher speed......
with the 43/ 44T Ball diff gear......
When the gear ratio is low , eg:9T=3.44
The TOP SPEED will be high , but the torque and the accelaration will be slow
vice versa ,
While you use the high gear ratio like 6T=5.17
The TOP SPEED will be slow , but good in torque and accelaration
For different tracks and road condition ,
you have to choose the best combination of gear ratio !