Avi- I recently installed a 300 amp alt on my boat. I too used a smaller pulley to get higher alternator revs at idle. I need the power to feed a 4000 watt inverter. Unfortunately, the tach signal comes from the alternator so now i have to compute engine revs. Where does the Tach signal originate on the Audi? Frank Santoro 1990 V8 (for sale) 1998 A8