Anyone who has created their own loom for these, did you use shielded wire to extend the standard loom from the ECU out to the coils themselves?

The loom I've built is quite short and keeps the signal wires well away from the HT leads and any other high current stuff, should i add some EMF shielding too?

 

They shouldn't need it, and I've personally never run shielded wire on IGNs when adapting to stock-ish setups or ground up race/dyno applications.

 

The OEM wiring diagram claims that the coil signal wires are shielded between the ECU and the ignitor. I haven't checked closely in the actual harness to confirm. I agree you will probably be fine either way; if I already had shielded wire available I would use it but I wouldn't delay a project waiting for an order of shielded wire to arrive. Try to keep the little rectangular 'condenser' (which is electrically the same as a capacitor) near the 12V supply and ground for the new coils, its purpose is to help the coils charge up quickly.

 

Good to know, thanks guys.

The wires running from the ECU to the Igniter are definitely not shielded. The signal wires that make up the coil short loom definitely are, the shielding all shares a common earth. I haven't pulled the main engine loom apart so not entirely sure if the shielding continues through that.