The High-Speed-S-Truder (HSST) with floating screw sleeve is an alternative extrusion concept with solid-melt-separation. A 35 mm screw with a length of 21 D, which is accelerated by a 75 kW gearless, water cooled synchronous drive, conveys the resin into a 60 mm screw sleeve. Inside the sleeve the material is plasticizied and emerging melt is discharged into the outer screw channel of the sleeve through radial bores. Therefore, a special screw geometry with three barrier elements is designed, which improves the melt removal in contrast to the HSST presented at the PPS-30. Thus, only the solid bed remains inside the screw channel. The development of a melt pool and a decrease of the plasticizing capacity is reduced. The sleeve is rotated by drag forces only and rotates with 10 % of the screw speed, approximately. Due to the lower speed of the screw sleeve molten material is conveyed to a Dynamic Mixing Ring (DMR) in a gentle manner. The granules in the screw channel are stopped by a barrier on the screw in front of this mixing device. So nearly no unmelted material can pass the system. The DMRs geometry is also optimized. Analytical investigations as well as CFD simulations were executed to find possible solutions to reduce shear stresses and dissipation inside the mixing device to fit the requirements of high screw speeds. For temperature management in the plastification and mixing zone a 3-zone heating/air-cooling system is used. Numerical simulations of the plastification processes in the HSST with and without improved geometries of screw and DMR were performed and compared. Theoretical background will be described in this paper. The efficiency and functionality of the enhancements are proved.