Its a mix of the gear box and the intake, our e36 rally car whistles a bit as well this thing is just amonster

He said short left 6 minus over crest, this means there is a 6 minus (basically a very slight turn) that turns left over a crest (a small knoll or hill you cant see on the other side). the minus means its on the tighter end of the spectrum. there is a plus and a minus to every severity of turn.