Nick,
http://homepage.ntlworld.com/captainslarty/r****d.exe
here is a little vb prog I have just compiled.. it will caclulate the delay needed to hold off the coil -ve lift in microseconds.
Just put the rpm required and the r****d in degrees, the end result is the delay time in microseconds.
thats how your unit is working the r****d function.
Joe..