1. Introduction. This thread has been made to store all the tips, tricks, and how-to's on the Legacy Twin Turbo, to single turbo conversion. The following content is based on my conversion, with some research from the ClubSUB forums, and other people who have done the conversion before me. This conversion applies only to the B and C revisions of the BG5/BD5 legacy, that have the EJ20R motor. It is not applicable to BH/BE's, or BG5/BD5 That have EJ20H's. Nor does it apply to the AUTO B's and C's