964 throttle body question

[Tbone425]

Anyone have an idea on what this arm is supposed to attach to? It a 964 3.6. It’s spring loaded arm that actuates a vacuum damper of some sort. Ther is nothing in line with the pull direction. Scratching my head over here…. Thanks!

[Tbone425]

Originally Posted by rsscotty

It is a vacuum actuator that controls the throttle plate in the tube below it. It is normally called resonance valve. Normally closed at lower rpm and open around 5300 via Motronic command.

Any idea where the arm is linked to? Thanks!

[Jim2]

That arm doesn’t connect to anything.

[winders]

Originally Posted by Jim2

That arm doesn’t connect to anything.

That would be completely incorrect!

Look here:

[Jim2]

Thats 993, not 964.

Originally Posted by winders

That would be completely incorrect!

Look here:

[540964]

The earliest 964 had 2 resonance flaps, later ones had only 1 flap but the vacuum actuator didn’t change. The photo is from Christophorus-May-1990. I have a pdf copy of the technical article that explains the resonance chamber, let me know if you’d like a copy.

[Jim2]

Perhaps you mean early had two butterflies, one resonance flap? I wasn't aware that there were two flaps.

Anyhow for OP Tbone, the extra arm on the resonance flap shaft wasn't connected to anything.

993 top (1995)
964 bottom (1989)

[Tbone425]

Originally Posted by Jim2

Perhaps you mean early had two butterflies, one resonance flap? I wasn't aware that there were two flaps.

Anyhow for OP Tbone, the extra arm on the resonance flap shaft wasn't connected to anything.

993 top (1995)
964 bottom (1989)

Thanks for saving me from going insane. 😆

[540964]

The earliest design had 2 resonance tube flaps. The linkage for the “slave” flap was connected to the lever the OP was concerned about. I’ve read about the original design when preparing to change all needle bearings and seals in my throttle body but I cannot find the documentation. Finally it does not matter because there is only 1 resonance flap in his throttle body and there is nothing connected to the lever. Same as mine.

[Jim2]

Thanks for the education 540964. Looking closer now at your Chritophorus article I see the second flap, I didn't see it at first.