Has anyone any idea how to wire a electronic tacho up to a coil pack? Basicly im running a 406 turbo engine in my 205 i have no rev counter im going to do a few track days and im worried about the noise test how can i prove what rpm im doing etc?

3 Zener diodes one from each coil firing wire, outer wires of the 3 pin plug joined to 1 diode that feeds the Tacho.
a diagram and diode specifications is shown on the megajolt site Autosportslabs.
It works, I have used it.

Spot on cheers mate