When I wired the AEM Wideband I was reading the instructions and saw that it has a cool feature I wasn't aware of- a built-in in data logger. It also has a 5v output to connect to an external data logger, which I knew about. I'm still researching how to hook that up to the input to the ECM that is currently being used by the EGR which will be deleted when I install the Whipple, so I can data log through my Autocal and incorporate the AFR / boost data into a log file I can send to BBP in order to tune. But back to the internal logger: it records 2 1/2 hours of data and loops so the latest 2 1/2 hours are available for download to my PC through the USB cable. Oh yeah, I bought a great little Dell laptop with Windows 7 for $65 shipped the other day. So when I was wiring the AEM I decided to hook up the optional wire to the tach so RPMs would be included in the log and I could see boost and AFR in relation to RPM. I looked through my wiring diagrams and saw there was a white tach wire going to the instrument cluster so I decided to give it a try. The instructions said it needed to be a square wave signal but I could only hope since I no longer own an oscilloscope. First it didn't work, and AEM was no help. Then I was messing around with the configuration in the laptop and set the pulse per revolution to 2 and boom! It works. That might be helpful to someone, who knows. Anyway, now I'll have some real useful data that I can analyze if I ever get this done lol.