The Bilstein B8 Performance Plus DampTronic is a rear monotube gas-pressure damper for the Porsche 911 997 chassis cars equipped with PASM, the factory electronically adjustable damping system. It is built for owners who have fitted lowering springs and want the factory PASM controls to keep working. Owners on user forums describe it as a shorter, firmer option than an OE-height replacement, and say it keeps the factory PASM switching intact.
A stock-length damper on a lowered car can run out of travel, and owners on user forums report that stock PASM shocks can bottom out once lowering springs are installed. The B8 is valved for that setup, which gives a more controlled, sportier feel than a basic OE-style replacement without giving up the electronic damping. Because feel is subjective, owners also report that the ride is noticeably firmer, so it is best suited to drivers who want a sharper car rather than a plush one.
Fitment is where buyers should slow down. Sources disagree on model years (2005–2012 versus 2005–2013) and on whether the damper covers only 4WD cars or both AWD and RWD cars, so confirm against your VIN and PASM equipment before ordering. Two rear dampers are needed per car, and the front dampers use separate Bilstein B8 DampTronic part numbers. This is a fit for a lowered 997 PASM rear shock, a Carrera 4S damper upgrade, or a Bilstein B8 DampTronic 26-118284 rebuild of worn factory units.
This part number is the PASM-compatible DampTronic unit. Owners on user forums note that Bilstein also builds B8 versions for cars without PASM, so confirm your car's suspension equipment before ordering.
Owners on user forums say the B8 is designed to pair with lowering springs such as H&R or Eibach. Sources differ on whether it suits standard ride height, so confirm with the manufacturer before fitting it to stock springs.
Per the manufacturer's directions as quoted by owners on user forums, the bump stop should not be reinstalled because the damper has an internal bump stop built in.
The rear is the easier axle on a 997 and is a realistic driveway job for an experienced DIY mechanic with a socket set, a torque wrench, and jack stands. Support the car on stands before removing any shock hardware. Owners on user forums advise checking drop link length before assembly, since one owner found the factory links too long for aftermarket shocks. Keep the PASM harness and controls connected so the electronic damping keeps working. Confirm orientation on both sides before final tightening, and use the manufacturer's torque values, which were not confirmed in this research.
