A diffuser system for a centrifugal compressor is provided. The diffuser system includes a nozzle base plate (206) that defines a diffuser gap (212), support blocks (216, 246), and a drive ring (220) rotatable relative to the support blocks. The drive ring includes cam tracks (224, 242) and bearing assemblies (226, 234) positioned proximate an outer circumference of the drive ring. The diffuser system further includes drive pins (214) extending through the support blocks and the nozzle base plate. The first end of each drive pin includes a cam follower (218) mounted into a cam track on the drive ring. The second end of each drive pin is coupled to a diffuser ring (208). Rotation of the drive ring causes axial movement of the drive pins by movement of the cam followers in the cam tracks. This results in movement of the diffuser ring to control fluid flow through the diffuser gap.