Variation of the plasma position relative to the centre of the helicalcoil winding is a very effective means of controlling the MHD stabilityand the trapped particle confinement in heliotron/torsatronsystems, but improving one of these two characteristics with this parameter simultaneouslyhas a detrimental effect on the other. The inward shifted configuration is favourable fordrift orbit optimization but is predicted to be unstable according to theMercier criterion. Various physics problems, such as electric fieldstructure, plasma rotation and MHD phenomena, have been studied in the Compact Helical System (CHS)with a compromise intermediate position. With this standardconfiguration, CHS has yielded experimental results that contribute to the understandingof general toroidal confinement physics and low aspect ratio helicalsystems. In the recent experiments, it was found that a wide rangeof inward shifted configurations give stable plasma dischargeswithout any restriction to the special pressure profile. Such an enhancedrange of operation made it possible to study experimentally thedrift orbit optimized configuration in heliotron/torsatronsystems. The effect of configuration improvement was studied withplasmas in a low collisionality regime.