The virtual reality (VR) industry has tried to enhance VR immersion, a perception of being physically present in a non-physical environment. Sound, simulators, and surrounding environments can be synergistically augmented together to enhance immersion in VR. In this paper, we first integrate an immersive virtual platform that builds on a moving vehicle simulator in an immersive virtual environment. The simulator is integrated to have efficient localization with inexpensive sensors and to produce the loosely synchronous motion according to dynamically changing VR simulations and contents. The virtual environment called an immersive room is designed to provide 360-degree videos experience and deliver VR contents without a head-mounted display (HMD). In addition, we investigate the quality of experience (QoE) via a comparative survey study between the proposed immersive virtual platform and the conventional VR using an HMD in terms of immersion and motion sickness. Through the human-subject study with the newly designed questionnaire, we confirm that the general QoE is improved in terms of immersion and motion sickness by using the proposed immersive virtual platform. To verify which factors in the loosely synchronous motion are effective in improving QoE, the components of the motion control are ablated to show their individual effects. We provide the statistical analysis to support our hypotheses that for the proposed VR platform, participants with the loosely synchronous motion are more immersed and less likely to feel motion sickness than those without the synchronous motion in both the immersive room and VR with HMD.