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LIRS6 · LIRS6's Garage

Saw this pic on an 83 SC sold on BaT yesterdy - can anyone tell me what that is on the airbox? Seller seemed not to know.

Edit : Having difficulty getting photo uploaded...

Jason

LIRS6 · LIRS6's Garage

75 911s · 75 911s's Garage

It's not a Porsche part. Some one has added what looks like flex fuel line to an attachment on the airbox strap. My next question is "Where do the other ends of those lines go? and is the airbox location just a convenient location or does the line penetrate the box at that area?

SiliconSurfer · 12-23-2025, 01:22 PM

It looks to me like some sort of pressure regulator plumbed into fuel or vacuum lines. Maybe someone was trying to get their CIS running right and this was the hack they came up with?

Tom_in_NH · 12-23-2025, 02:16 PM

My guess is that its a pressure regulator plumbed into the control pressure to tune a non-stock engine.

ant7 · ant7's Garage

I wonder if it was an additional power operated valve plumbed into the breather system, maybe to over-ride the thermo switch on the inlet manifold[not sure the SC had this system] ? Or connected to the Vacuum advance on the distributor to alter the timing ?
Worth a guess ?
Ant.

pmax · pmax's Garage

Quote:

Originally Posted by Tom_in_NH

My guess is that its a pressure regulator plumbed into the control pressure to tune a non-stock engine.

That would be my guess too.

The "securing" on the plastic airbox lid part though, there's probably a better place to attach the unit.