13 As of mid-1999, the Z3's main crankcase pulley (at the right) is a single piece unit with the surrounding vibration dampener ring (the wide diameter section at the bottom). The dampener cannot be removed and installed on the Unorthodox pulley.
Alain then telephoned an engineer at Unorthodox Racing to relay our findings and determine if they had any solutions. It immediately became obvious that when the head driver of an SCCA race team telephones an aftermarket supplier, the level of cooperation is much higher than when I had called several weeks earlier. As best as I can determine, it seems that Unorthodox had some awareness that the pulley arrangement in the Z3 had changed in mid-1999. However, they had never received any real fitment complaints and had never formally tested their pulleys on a MY2000 vehicle, despite their prior assurances to me that the application worked. In fact, the Unorthodox engineer talking with Alain seemed surprised at first that the vibration dampener could not be separated from the factory crankcase pulley. The engineer then suggested to Alain that the Unorthodox crankcase pulley should be installed bare, with no vibration dampener.
After the phone conversation with Unorthodox, Alain and I spent several minutes going over the possibilities. He was extremely dubious about installing a main crank pulley with no vibration dampener in the front. Admittedly, I would still have the flywheel at the rear of the engine to absorb vibration. From experience, Alain told me that no matter how well balanced the engine and crankshaft may be, there would still be a noticeable loss in smoothness to the engine and there would be additional stress placed on a crankshaft that is not designed for flexibility. The bad news would be that my crankshaft might last 10-20K miles and then snap. The good news would be that BMW would probably buy me a new engine. Ultimately, the decision was up to me based on the facts.