If I may, I would like to point some cool things out. Adding a coil to any secondary in series will only act as if you added more windings to the secondary in effect, increasing the voltage. The way a VIC is drawn in most cases, the core the chokes need to be wound on is not shown, although, an important detail not to be missed. The Chokes do not have to be coupled to the primary/secondary core to work. They do, however, need to be coupled to their own core if not to the primary/secondary.
You will need to find the resonant frequencies of this choke coil. We can do this easily with just a 12-24v incandescent light bulb or 90v neon, the choke coils and a variable frequency generator. Play around with the circuit a bit and you will find the coils, at certain frequencies, will have a difference in brightnesses. The brighter the bulb, the more current is passing through the circuit. Find frequencies where the bulb goes out or very dim and you should be able to measure higher voltages with the right equipment. Try anything you have to measure just in case. Take note of these frequencies and next, set out to modify your driving signal from the alternator. This is a bit of a backwards way of doing it, but, it's cheap and easy. You can repeat the test with just the alternator and coil/light bulb too for further tuning, since, the alternator will change the parameters of the over all circuit also changing the resonant frequencies of the coil.
One last tidbit... When dealing with resonant frequencies in a circuit such as the VIC. We must realize the circuit as a whole is affecting the resonant frequencies of the coils for the fact of parasitic and distributed inductance and capacitance. When you connect a transformer to a choke, the choke will add the transformers inductance and capacitance to the circuit. Some times just putting your hand close to the device will also change the resonant frequency. For these same reasons, it is good practice to keep leads short as possible with components in your electrical experiments.
God bless!
Bubz
