Altering variocam activation for additional power

[Steve W]

Does anyone know anything about altering the activation of the Variocam system to increase the low/midrange power? A Cup car tech had tried to explain to me some of the different power tricks they were using on the GT3 motors, and was trying to describe about how to alter a vacuum line by the intake manifold which alters the intake cam timing on street cars which is initially set for emissions. Without a factory manual of the workings of the motor, none of this was clear to me.

[george996]

for whatever it's worth, the 2002-2004 normaly aspirated 996's with 7.8dme do not have intake manifold vacuum sensors, therefore cam timing and valve lift are actuated from other inputs (i.e. rpm, load, etc.). I have the dme manuals and will look for info on the gt3's.