Programming Issues with Crab Drive System

[bls0620]

So...... we finally got to test our new crab drive system today(actually last night )). However, we experienced some electrical/programming issues.

So this is how our programming works.
Our crab drive has two drive modules on left and right. (each module controls direction of each side, since two wheels are chained together)\

Each side has absolute magnetic encoder attached to it. We use those encoders to measure the current value(angle) and get reference from a joystick to calculate the error for PID.

These are the issues we found so far:
1. Unsynchronized drive modules
2. Drive modules not turning fast enough (PID issues)
3. Overshoots (PID issues again...)

Is there some ways to improve our PID for fast and accurate control? Other than PID control, is there a way to synchronize both modules so they will turn at the same rate(in an efficient way)?

BTW, We are using LabVIEW