I looked it up last night. In the AVS, its called air valve (the name AVS is Air Valve Secondaries). D^2 Quoting Brian Collinsworth <67imperial@xxxxxxxxxxxx>: > I am pretty sure it is simply called an air door. > Brian > > > > > > Correct, the actual butterfly is mechanically controlled by the > throttle > > position and the top flap (is there a real name for that part?) is > > controlled by a few factors. > >