911 vacuum line question

[Tall02]

Dear Fellow Porschers

I am helping a freind with his 1988 930. He purchased the 1988 930 body that was slightly converted to a track vehicle which came with no engine. We are in the process on converting it back to a street car. Not able to find a 1988 turbo my friend purchased a 76 930 3.0 turbo engine that has been updated with a 1986 3.2 regular aspirated manifold, throttle body and fuel injection. We are also incorporating a TEC3 engine management system.

I have found that there are two optional vacuum line circuits on a 1988 Carrera. Why is option A simple and option B have more components. I understand that one port on item #13 is to the brake booster but what is connected to the second port on item #13?

Any advise, photos or assistance would be appreciated on our 930 project.

Thanks
Keith

[avt007]

On my 86 non Turbo, I threw away all those fittings, and I just run a single vacuum line from the manifold to the brake booster. No venturi, no hose to the intake boot above the throttle, nothing. Works great!
I would not hesitate to do it again.

[Tall02]

Does anyone who rebuilds Porsche 911 engines know why there are two style vacuum lines offered? And if the brake booster is hooked up to the #13 fitting what is the second port hooked up to?

Help

Keith

[avt007]

The second line off of p/n 13 goes to the rubber intake boot between the AFM and the throttle body. If I recall correctly, it was some sort of vacuum booster rig. To what end, I don't know. I do know I tossed it all out over 2 years ago, with no regrets.