logging differential voltages

[vprtech]

Hello, I'm working on putting together a logging setup for older race cars using first generation Bosch Motorsport ecus. My goal is to physically tap into the Bosch sensor voltages and digital channels: such as map, baro, tps, cts, ait, map switch, mixture switch, injector pulse, tach output, as well as some stand alone channels: fuel pressure, baro, oil pressure, map pressure, multiple K type egts, etc.

To get decent data, I image I will need to measure the voltage differential of each channel, and I don't see how this can be done with a ADL or CDL directly. Also, I am aware of the VIM module, with lists eight differential voltage channels, however I am looking to go with the simplest(and most cost effective) solution possible, and this would exclude the VIM.

Any ideas, or suggestions are appreciated.

- Chris

[David Ferguson]

Why can't you use the common ground with the Bosch ECU?