tandem oil pump
 

so, the 9x7 cars have a vacuum/oil tandem pump. apparently provides better vacuum for brake booster, resonance flapper, etc. from what i can see, 9x6 and 9x7 oil pumps are interchangeable (parts catalogs actually carry a 997 part number for 986 oil pumps).

so, question is - anyone swapped in a later pump on their car for better vacuum?

.....hmmm i still haven't even done the little 997 pressure plunger!

And I thought on the 986/987 cars the intake supplied vacuum to those users and also vacuum to the crankcase through the AOS.

Edit; After a search I see this as a requirement for a turbo since intake may be pressurized and not under vacuum.

for brakes, resonance flapper, secondary air injection, 9x6 cars got vacuum from intake; 9x7 cars got vacuum from the pump. aos gets vacuum from the intake on both.