You can record up to 9 hrs of data. Not sure what Marc may have been refering too. But the ZT-2 box is a datalogger and they have the guage for real time or the LCD (which I got with it) that you can recall highest reading and look at while you are driving.
Its awesome! The problem with the LM1 which is a very good box has always been ground issues and the rpm being accurate. Not to mention it costs a boat load to get all the sensors you may want.
I am recording fuel pressure, Wideband O2, boost, rpm, intake temp (used for water/meth spray)
I can email you the directions if you want. Shows you how to datalog