[ltusler]

Well.....
I have Raby rebuilt 2002 3.8 X51 VCAM+ in a 99 996 chassis.
There should be 2 solenoids one on each side of your engine the trigger the switchover.
Mine uses a MSD 8969 RPM window switch to turn on and off the VCAM.
Its triggered by the RPM lead at the ECU, on at 3200 off at 6500.
When triggered, it grounds a relay connected to the VCAM solenoids.
It does not use the full infinite adjustment ability in the + system, but I don't care. Its a track car that spends most of its time at RPM from 5 to 7.5k.
The conversion was done in in 2004. It ran over 9k miles before the crank became a 2 piece.
It now has over 3k on the rebuild and is running fantastic.