Mazda RX-8 2004 Service Highlights page 290

Without PPF
— In order to suppress vibration to the vehicle body, rubber mounts are used to connect the differential to the
frame. When accelerating rapidly, the front part of the differential lifts upward which causes a time lag in the
actual engine torque being transmitted to the tires and direct drive feeling is lost.
With PPF
— With PPF, the transmission and differential are joined in a single unit which, even though the differential can be
separated from the body, time lag is lessened due to the near elimination of lift, creating a feeling of direct drive.
Furthermore, shock and vibration during acceleration and deceleration is greatly reduced.
WITHOUT PPF
WITH PPF
End Of Sie
MANUAL TRANSMISSION [Y16M-D]
POWER PLANT FRAME (PPF)
LIFT
RUBBER MOUNT
05–11–13
05–11
CHU0511S014