Spearing Britney
In JAR 25, performance is based on engine failing at Vef speed with a lag time accounted for reject actions to be started by V1. Initiating reject actions at a speed greater than V1 will greatly enhance the chances of a runway excursion.
KeithL - sorry I did not read the bit about 15kts below V1 for a fire bell, I read the bit about 15 kts for an overheat. Just out of interest on your abort did the warning occur 2 kts below V1 or was that when you started your actions?