When we say "race against time," we are usually under some sort of deadline. A synonym for this phrase is "against the clock," which implies that time is ticking away and the task must be completed quickly. Another synonym is "time crunch," which also implies a sense of urgency and a limited amount of time. "Deadline dash" is another option, which emphasizes the need for speed to meet a deadline. "Time pressure" is a variation on the theme that conveys a sense of stress and tension. Finally, "time squeeze" also denotes a sense of being pressed for time, needing to get things done quickly, and making the most of the limited time available.