Lloyd and Pete...
I'm confused. Points, dwell, etc., are new to me.
Dwell is the time during which the coils are charged. With the stock points, that is controlled by the cam that the points ride upon, assuming the gap is set correctly when riding on the highest crown of the points cam.
Does the Pamco unit charge the coils for the same duration as the stock points setup?
No, the Pamco charges the coils for 120 degrees of crankshaft rotation, rather than the stock 195 degrees.
If not, what is the significance of the difference?
The stock points and it's cam will allow the stock coils to receive full charge at higher RPMs than the Pamco can.
Is it possible that while the Pamco unit could perform better than stock with high-performance coils, it could perform worse than stock points with the stock coils?
Yes, depending on how high an RPM you wish to operate. (And, what parameters you specify for "perform" and "better". What is "better" going to buy you?)
Here is my analysis:
A coil takes 5 Time constants to achieve full charge, and they charge on an exponential curve. See 1st chart below:
According to Mark Paris (Hondaman), It takes 1.5 ms to charge the stock coils to 96%, which is at or very near the 3T point on the graph. See second chart below:
Note the charge rate slows as it gets nearer to 100%, as the charge curve is non-linear.
Divide 1.5 by 3 and you get .5ms as 1 Time constant, making 5T = 2.5 ms to reach 100% charge.
A 10,000 RPM, the stock points allow 3.25 msec. for charging the coils, while the Pamco charges the coils for 2 msec. At this RPM, the Pamco will not fully saturate the stock coils.
I would assume the Pamco was optimized for a lower RPM engine, as 120 degrees would certainly be acceptable if high RPM operation is never expected while using the stock SOHC4 coils. With some more number crunching, I could find the max RPM the Pamco will support with the stock coils. Perhaps Pete will even share this, as surely he should know the limits of his device.
It is also possible that your engine can still "work" without charging the coils to 100% at some high RPM point. It is a matter of parameter trade offs to select what works for the environment/envelope you wish to operate within. Also remember that operational assumptions assume 100% function of the spark plugs, wires, connectors, plug caps, etc. Degradation of these parts can expose less than 100% charge of the coils. (Still need to assume the stock cylinder compression parameters, too.)
If I understand the Pamco ignition history, it was developed for the XS650, which has a red line of 7500 RPM and it's routine operation is below that. It's not hard to believe 120 degrees of dwell/coil charge time was a good trade off between power usage and still fully saturating the coils. Perhaps the coils he prefers, charge faster than the stock coils? Certainly not all coil designs will charge at the same rate as stock coils. Yes, it will "work" with the stock coils. But, there are RPM limitations because of the parameters that were chosen. Further, there are additional factors I can't calculate without knowing what's "inside the box" (or a test sample). For example, I don't know what electrical switch was used to gate the power to the coils. It may have slow on time/ rapid off time, or it may have some internal resistance which would also effect charging the coils fully (or not). I can't determine this, because the salesman was more interested in collecting money than fully describing how the unit operated, besides "good", and a "buy-it-you'll-like-it" promise.
In contrast, points contacts closing and opening is fairly easy to characterize electrically. Electronic devices are often sold similarly to "magic", and the actual electrical performance limits/function are hidden from the user, as they don't "need to know" much like oil companies will sell oil based on "better" without actually explaining in technical terms, why. Many consumers just glaze over at such details besides consumer cost, does it look pretty, and simply expect the device purchased to work based on faith. I've been disappointed too often, and where I have the capability, I can often determine pre-purchase, if the device is what it seems, provided I have sufficient data. I'm not much of a gambler, and I don't wish to replace something on my bike that is known to function well, with something that may or may not be well suited for it. But, then Las Vegas gets lots of visitors, so it is clear I am in the minority.
Anyway, you are asking for what is "better" without ever stating what performance envelope you require. It is really an unfair question. Only the angels deal in absolutes. We live in a world with shades of gray. I expect you aren't standing on the edge of a cliff blindfolded and asking for directions.
If you want to keep the stock coils, and still have the Honda specified coil charging characteristics, the only "known" unit that maintains the relationship is the Hondaman ignition, which uses the stock points and cam. The Dyna-s won't do it, the Pamco won't do it in their current forms. There are other points eliminators out there, that I have no data for characterized operation; Prestolite and Boyer Brandson come to mind. But, like many, functional data is not distributed freely by them either. You have to buy into their "faith" and pay them for the opportunity to "test" it. Hondaman made all the data available for his unit upon introduction. Which made it "easy" to determine it's value and function before purchase.
Hopefully, you now have the information you seek.
For the rest... let the flaming and ridicule begin!
