as a 2-step trigger, use the transbrake circuit.

As a retard, you can use a button/switch, the N2O arming circuit, or a pressure switch (boost).

The retards dont start 'retarding' until 3000 RPM so you can leave them on all the time if you want (that's how I set up my car).

Bob

 

im going to be mounting a 2 bar map sensor to my engine just to control the retard in that aspect and use your ignition box...