Re: Answer to making 745i run with chip. (archive)

The way the hose to the waste gate works is it is taking boost (positive manifold pressure) from the compressor side of the turbo and blowing it in the waste gate valve "lifting" it up the waste gate causing boost to be bled off as boost increases. This is done through the solenoid that hangs off your air cleaner. The solenoid serves 2 purposes. 1, it is controlled by the motronic to open at 6 psi swithcing the positive pressure to "hold open" the waste gate at that point. 2, if the knock sensors detect a knock, it will switch and blow open at any level even below 6 psi. If the hose is unpluged, you no longer have the positive pressure blowing open your valve limiting your boost, but only the actual force of the total boost pressure (which is about 12 psi limited by the spring pressure in the waste gate)

Hey Matt,

Where is this "actual force" of the total boost pressure coming from????? Is there another way the WG gets boost to it, some internal passage though the ehaust manifold? I dont think so. If you where to unplug the hose between the selenoid and the WG and connect it between the manifold and the WG then I understand. If you have no hoses (possitive psi) connected to the WG it won't open. Please explain to me where this "actual force" is comming from.

Alex

Follow Ups:

[ Follow Ups ] [ 7-series (E23) Message Board ] [ Msg. Board FAQ ]

Questions, comments, or problems, please visit the Roadfly help desk.