In this work we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. Three-dimensional (3D) spectra and maps of Mrk 231 clearly show that the BAL systems I and II are extended (reaching 1.2--1.3 kpc, from the nucleus) and elongated at the position angle (PA) close to the radio jet PA. For the nuclear region of Mrk 231, the QSO and host-galaxy components were modelled, using a new technique of decoupling 3D spectra. From this study, the following main result were found: in the pure host galaxy spectrum an extreme blue nuclear starburst component was clearly observed. 3D GMOS individual spectra (specially in the near IR Ca II triplet) and maps confirm the presence of an extreme and young nuclear starburst (8 < age < 15 Myr), which was detected mainly in a ring/toroid (r = 0.3" = 200 pc). The physical properties of the 4 expanding nuclear bubbles (in Mrk 231) and the NLR were analysed. Finally, the composite hyper-wind scenario is suggested for the origin of BALs and giant Ly-alpha blobs. The importance of study the end phase of BAL+IR QSOs, and ellipticals (i.e. galaxy remnants) is discussed.