coil pack pin out?

[Evans]

each coilpack has a connector with 3 wires. (+) (-) (E)
i know what the pos and neg are but what is the (E)?
asking because i want to convert the stock coil system to a spark plug wire with blasters system. and since a typical coil pack requires only 2 wires what one would be left out and what would i do with it?

[DarkCaporaL]

The E goes to earth and it stands for Engine Ground.

I can't really help with your other question regarding blaster systems...