What is Surging?
Compressor surge is where the air backs up in the compressor and oscillates violently within the compressor wheel. This happens when the engine’s swallowing capacity is exceded by the compressor’s output. The technical definition is when the pressure after the compressor exceeds the radial velocity component of the compressor wheel’s output which causes the air to back up. The sensation is somewhat akin to getting on the pedal and simultaneously then getting off it, many times, the car feels like its bucking, acceleration, deceleration, acceleration, etc.
