[DonRotolo]

I'm not a programmer, so I can't really help much there. However I do know mechanical pretty well, and a curving drivetrain means that there's something mechanically wrong with your drivetrain.

Get the mechanical guys to fix the problem. Otherwise you will be always reducing power to one side to compensate for the drivetrain problem. With the drive motors disconnected, you will find that one side of the drivetrain requires more effort to move than the other.

That being said, encoders on your drive motors are generally a good idea, especially when you're trying to move a specific distance in autonomous.