ok here is the thing. according to ndswngs you can run it without a tach adapter but in order to get a clean signal to datalog you will need one. its 50 50 in my opinion. they said the same thing about the avc-r. i ran it for the longest without one then finally bought one and it ran about the same, maybe slightly better. its really on you though. oh and here is the link:
Zeitronix Install Notes for SRT-4
