Because there are so many different engine ignition systems, we have developed several methods to measure engine RPM. DTM-IPU Inductive Pickup. This method involves tie wrapping a wire from our harness to a plug wire or secondary wire from the ignition coil. We have also had good luck placing this wire near the coil on a “coil on plug” type engine. BB2-IPULV Low Voltage Inductive Pickup This sensor clips to a low voltage wire, like the coil primary wire or fuel injector wire. DT2-RPMR Reflective Optical RPM Sensor This sensor “watches” a piece of reflective tape you will place on something spinning at engine RPM, like the crank pulley or dampener. This method is VERY reliable and universal, but requires with you coming up with a bracket. The sensor has a red “pointer” beam which greatly aids the setup process. Calculate Engine RPM from Dyno RPM The software allows you to CALCULATE engine RPM from dyno wheel RPM from simple vehicle measurements or from a simple calibration test (Pro ver