This thesis investigates high-speed trajectory tracking and longitudinal speed optimization for an autonomous racing vehicle following a predefined racing line. To address the strong coupling between lateral and longitudinal vehicle dynamics during corner entry braking, trail braking, mid-corner tracking, and corner exit acceleration, a control framework combining offline speed profile generation, online speed profile adaptation, and model predictive control is developed. First, an aggressive offline speed profile is generated along the reference path based on track curvature, tire friction limits, longitudinal acceleration and braking constraints, and vehicle performance limits. Since the offline profile does not account for the real-time vehicle state, an online speed profile generator is further introduced.