If you have the old school fmf gold series, its going to be identical with the T5 power wise, it just may have slightly more midrange power. Your going in the wrong direction to find the right pipe for what your explaining you do. low-mid pipes are the fmf gnarly, pro circuits, pt mids, etc.... Not cpi, shearer, T5, fmf gold series, fmf fatty, fmf sst, etc...... All this info is available on the search, and again, I would not base anything on how a pipe sounds.