At what RPM is the alternator on a 1986 911 Turbo generating maximum output? I'm curious to know, as I have a freind who experienced a lean situation when he was breaking in his newly rebuilt engine. According to the logs captured from his TEC3-R during the dyno process, the current flow dropped dramatically when his car got to 4K, which he believes led to low enough voltage that failed to provide a long enough pulse for the electronic injectors. Any ideas as to how to track down the source of this problem? One person suggested that it might be due to a slipping alternator belt. The theory is that the newly powdercoated surface on the pulley half is causing one side of the belt to lack equal adhesion as the bear side, causing it to tilt sideways, and leading to slippage. There was no audible noise from the belt while the engine was running and no one noticed the fan turning at a slower speed as the RPM's went up. FYI, the alternator and battery are brand new.

Thanks,
David