We study event-triggered control for stabilization of unstable linear plants over rate-limited communication channels subject to unknown, bounded delay. Event triggering carries implicit information, revealing the state of the plant. However, the delay in the communication channel causes information loss, as it makes the state information out of date. Combining these two effects, we show a phase transition behavior in the transmission rate required for stabilization using a given event-triggering strategy. We consider both scalar and vector linear systems with and without disturbances.