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Modified rear trailing arm pick up point to accomodate better camber adjustment

Having your classic 911 sit on its wheels in a well-balanced manner makes an incredible difference in its road behavior. Sounds like it makes perfect sense, right? You’d be surprised what we find has been done to guests at the TwinSpark Racing Lair!

To be able to fit short, RSR or Turbo trailing arms (no, they are not the same…), a modification to the non-RSR (who owns a real one these days?) non-Turbo tub needs to be performed. The pick up points for the rear trailing arms need to be raised and moved sideways. This allows the short trailing arms to provide a sturdier stance to your car.

Sounds easy, but to get this cut and weld job done accurately, a special rig is needed to simulate the set up of the rear suspension. A few year ago we found out that we couldn’t drop our 1973 RSR (originally a 1973 S) sufficiently without generating massive negative camber. Measuring things showed that the pickup points were welded in too low. A few millimeters off there means centimeters and many degrees off at the wheel. So, one Christmas holiday Lex dropped the engine and gearbox and got to work on the bodge job of the previous owner. This involved cutting windows in the rear seat bowls to be able to cut and weld the top of the pick up points on the torsion tube.

Woodstock’s ride height can now be set properly, for Road or Race purposes.

When we started to race The Hulk, we noticed that it suffered from the same problem as Woodstock, but we had different priorities and managed to win the Historic GT & TC championship in Holland, riding at rally height nonetheless….

Test fitting steel RSR Trailing Arms and Zuffenhaus RSR Brakes

Now the time had come to deal with the problem, as we needed to start using steel trailing arms as our final step in bringing the car in compliance with homologation. For years scrutineers had accepted Turbo arms as a solution, but those days are over. So last week the pick up points were modified and we were ready to mount the steel trailing arms and Zuffenhaus RSR brakes.

The trailing arms are exact copies of the 2.8 RSR trailing arms and now we face the challenge of mounting the right wheel bearings, flanges, disks and align the brakes. Everything is off by a few millimeters, so stay tuned to learn how we are resolving the mystery!