BSKZ650 wrote:
allright stupid question time, why would you want less power to the coils at lower speeds?
when I was in the gas compressor industry we wanted the most output from the coils to the plugs, some of those ignition systems could jump a HOT SPARK over 1 1/2 inches.
it seems to me that you would want the hottest spark at all speeds to burn the fuel as efficant as possible no matter what rpm
A coil's primary current increases gradually when voltage is applied to them. The current is proportional to the energy stored in the coil. It takes time to build up. Once it reaches its maximum current, any more time will not increase the coil's current. This means the available spark energy is maximized, and the coil cannot store any more energy. Any more time spent at maximum current will only go into heating the coil. This extra energy is simply wasted as heat.
The Dyna S has the coil's current at maximum-current for about twice as long as the stock points setup, and 3 times as long as the stock electronic ignition setup. This is in order to ensure maximum spark energy at higher RPMs (where there is much less time available to build up current). So you suffer power-waste at low RPMs but get higher spark energy at higher RPMs (where older engines have trouble).
An ideal system would apply the voltage to the coil for the same amount of time regardless of RPM. The amount of time would be exactly how long it takes to charge the coil to maximize spark energy, and no longer. This requires a much more intelligent system than the Dyna S.
Actually, the early KZ electronic ignition does this to a very small extent. At idle the dwell is around 100 deg, while at higher RPMs it's around 120 deg.
...and yes, I should have said "selectable pre-programmed curves" instead of "programmable" curves.
Thanks for clarifying. I'd imagine there are some small switches or something on the box.
Post edited by: loudhvx, at: 2007/04/05 02:46