A turbo compressor assembly, comprising: - an air intake channel, - a compressor wheel, - an insert unit, and - an actuator unit, the air intake channel being configured to draw air to the compressor wheel, the compressor wheel being configured to rotate for compressing the drawn air, the insert unit being arranged between the air intake channel and the compressor wheel and configured to control an airflow to the compressor wheel, the actuator unit being connected to the insert unit and configured to move the insert unit at least partially along the air intake channel parallel to a rotation axis of the compressor wheel, the turbo compressor assembly further comprising a transition element between the compressor wheel and the air intake channel, the insert unit being movable along an inner surface of the transition element, and the transition element comprising a first end portion and a second end portion, the first end portion facing the compressor wheel and the second end portion facing the air intake channel, an inner diameter of the first end portion being smaller than an inner diameter of the second end portion of the transition element, the insert unit comprising a guiding means facing the compressor wheel, the guiding means being configured to induce pre-swirl of the airflow ahead of the compressor wheel, the guiding means comprising several tab elements, the tab elements being arranged around the rotation axis of the compressor wheel and substantially parallel to the rotation axis of the compressor wheel, and the tab elements being arranged inclined in a rotation direction of the compressor wheel. - an air intake channel, - a compressor wheel, - an insert unit, and - an actuator unit, the air intake channel being configured to draw air to the compressor wheel, the compressor wheel being configured to rotate for compressing the drawn air, the insert unit being arranged between the air intake channel and the compressor wheel and configured to control an airflow to the compressor wheel, the actuator unit being connected to the insert unit and configured to move the insert unit at least partially along the air intake channel parallel to a rotation axis of the compressor wheel, the turbo compressor assembly further comprising a transition element between the compressor wheel and the air intake channel, the insert unit being movable along an inner surface of the transition element, and the transition element comprising a first end portion and a second end portion, the first end portion facing the compressor wheel and the second end portion facing the air intake channel, an inner diameter of the first end portion being smaller than an inner diameter of the second end portion of the transition element, the insert unit comprising a guiding means facing the compressor wheel, the guiding means being configured to induce pre-swirl of the airflow ahead of the compressor wheel, the guiding means comprising several tab elements, the tab elements being arranged around the rotation axis of the compressor wheel and substantially parallel to the rotation axis of the compressor wheel, and the tab elements being arranged inclined in a rotation direction of the compressor wheel.