The timing 'could' be out if it feels slow compared to other RS Clios !? Is it completely standard ? When were the belts last done ? How many miles and how old's the car ?
These things do have more of a kick between 5 and 7k. Max power should be around 6.6k...
My old one felt awful from 1-3k, 3-5 was alright, 5-7 pulled hard. Had matched inlets fitted and it pulled hard from 1500RPM !