We’ve just fitted KW Suspension’s latest V3 kit for impact bumper 911s to this 1979 Porsche 911 SC. The conversion from standard Bilstein struts and rear dampers to the adjustable KW kit was very straightforward. We also took the opportunity to change the rear spring plates complete with suspension bushes and covers as the originals were in a pretty bad state.

Our photos show just how much wear the spring plate bushes had endured since 1979: almost forty years ago! Such wear is common on an old Porsche and causes big changes in suspension geometry under acceleration and braking. Sudden geo changes are the root cause of the dangerous rear-steer characteristics found in many older 911s. Suspension bushes deserve careful inspection every service and replacement when worn.

KW’s latest suspension kit is one of two full kits suitable for the impact bumper 911s. The kit fitted to this Porsche 911 SC uses the original torsion bar setup, while the track-friendly Clubsport kit does away with the torsion bars and goes to full coilover suspension. This would be overkill for purely road-use 911s. The V3 kit with its galvanised steel body and adjustable rebound and compression certainly impressed our very own tame racing driver on road test, following a full 4-wheel alignment once the new dampers had been fitted.

“The new KW suspension feels great on this classic 911,” said JZM Technical Director, Steve McHale. “Not too stiff but solid on the road. By replacing the old parts with modern KW dampers, the car feels planted and confident. This kit is the perfect upgrade for cars with older, worn-out dampers, especially when the suspension bushes may also be in need of replacement.”

Email JZM Parts to discuss fitting details and prices for the V3 kit for impact-bumper 911s including the Porsche 911 SC, Carrera 3.2 and 930 Turbo models.