A similar ratio, only we are dealing with half the voltage. So if there is a 2.6 volt drop for example thru the coil with 12 volts, there will be a 1.3 volt drop with 6 volts. In theory. A person needs to prove that to themselves by measuring the voltage in three places.. 1) before the ballast resistor, 2) After the ballast resistor and 3) at the negative side of the coil which is the same as measuring at the points.
You know me by now Tim. 100 words or less isn't my specialty. The coil is a transformer and has something called a turn ratio. The number of turns in the primary determines its ohm value. Both coils (if you insist on thinking there are two) measure the same ohm value.
A good exercise just so you understand yourself how it works is to make these measurements and also measure the ohms of the ballast resistor with it out of the circuit and the coil with it out of the circuit. Then plug in the numbers.
I was surprised to learn the 6 volt coil ran the HEI system perfectly as well. Not as hot a spark as the high performance one, but kept up just fine.
