bon, j'avais tout faux

, mais j'ai eu la VRAI et BONNE réponse
donc ça s'appelle le "compressor surge"
Compressor surge is a phenomenon experienced when boost pressure inside
the intake tract builds up and has no convenient relief method. This is
usually caused from the throttle plate closing quickly. Changing load
conditions (off throttle) resulting in varying amounts of exhaust gas can
also simulate such conditions. In such a case, the pressure takes the
only way out through the turbocharger compressor housing. The unique
sound is caused by the pressure charge encountering the spinning
compressor wheel on its escape from the engine. Compressor surge goes by
many other names such as compressor stall, turbo dose or dosing, pigeon,
turbo flutter/chatter and sometimes mistakenly wastegate chatter. The car
was thoroughly warmed up before filming. The boost controller has been
disabled allowing the car to run directly off wastegate pressure.
http://www.youtube.com/watch?v=LZUbo_mNDZM&eurl=http%3A%2F%2Fvideo%2Egoogle%2Efr%2Fvideosearch%3Fq%3Dcompressor%2Bsurge%26hl%3Dfr%26emb%3D0%26aq%3Df&feature=player_embedded