joedrum":3007xa8g said:
this is a good thread cm85 and the speaker cable spark wire has me ...need to get cm to tell me exactly what i want ....tory ..dave ... and the cm85 coils setups ..have got me also ...there all looking rather good...and there sure is a need here ...im running out of coils that work
I don't want to derail the thread from it's primary topic, the CBR coils, right?
But, I'll start with a begining from my point of view. I'll be as open as I can be right now.
It's only partially about the coils.
Let us take a module from the GL1000 Dyna "S" triggering set-up and look at it, for it is more than just a switching device.
IF we know what the circuit actually is inside the module, and then we know the individual components and their values, then we can start a baseline for modification.
What do we want to modify and why?
Imaging for a moment the evolution of Dyna to the "S" model ignition for our 1000's (or any other bike). If we go from the model "III" ignition set-up to the "S" set-up, we see that Dyna simply took the external "III" model driver and placed it within the casing of each individual "S" model module. The difference in the physical structures of the switching devices (modules, "III" vs. "S") may be a clue to this. Whereas the "III" model had its heat dissapating qualities embedded in the external, frame-mounted aluminum-housed driver, the "S" model relies on dissapating heat, as a heatsink, through the pick-ups baseplate. Not ideal in my opinion, and possibly a good reason we here of x-number of failures of the "S" model modules (3/4 module in my case, and from what I've been reading on the 'net). This is a side-point really, bt it's Dyna's way of reducing costs, re-packaging a basically unchanged "III" ignition to market something new and "improved?" to keep their wheel turning (just my opinion of course).
If we know the design limitations of a key individual part, its power transistor, and can then either exploit its maximum potential or change the part itself to give us what we want, then a higher level of performance might be found. Many variables happen here. I won't go into them now.
IF our usual supply voltage to these drivers (Dyna internal module "S" or the external module of the "III") is found through either system voltage or direct battery voltage, then we are not pushing these components to their electrical maximums. Again, many variables exist on how to do this reliably, day-in and day-out.
IF, for example, we do what the car stereo crowd does with their amplifiers, or what the CB crowd does with their amplifiers, then why can we not do the same? ...that is: "overdrive" the circuit (overdrive is incorrect, but the word has its place in 13.6vdc terms) to achieve higher performance from the components and still remain within maximum design limits. Now keep in mind, many in the stereo and cb realms run their equipment up to 20vdc input.
So, what is the design limit of input voltage to a Dyna driver. Well, that is the key. The coils are only part of the 22Kv equation.
Heat dissapation is the ultimate concern with any of it.
I'll be putting-up a datasheet on the exact transistor supplied in the Dyna "S" models' module with various techniques on manipulating voltages and alternatives to transistor replacement. I've many notes to sort through. An example is a mil-spec power resistor replacing our standard ballast resistor choices using not only a finned aluminum heat-sink, but fan-controlled "water" cooling to keep it at a maximum temperature and no higher much in the same way that your computer is using for it's motherboard processor, assuming you're running a water-cooled processor. I've a lot of stuff to sort just in the ignition area.
I'm certain I've forgot something in my typing-to-thinking process...
I will say that my ignition sees a minimum of no less than 15.4vdc at any RPM, no matter what. It has a input celing of 19vdc and no higher.
