Electronic Ignition

[ericpritchard]

Just thought I would share recent experience with electronic ignition for my Ducati NC 250 race bike.
I’ve been racing Ducati singles for about 10 years and often thought about electronic ignitions (having had them on my Triumph road and comp bikes for many years before that). The stopping point for me was always accurate setup of the ignition timing on the bench without the motor running. Even if I waited to set the timing when the motor was running, I then would have to figure a way to strobe accurately (I now know that there are strobe devices that fit to the clutch side outer cover, however, that doesn’t solve my first point).
I came across a device that solves my problems in that it has a built in led that enables set up on the bench, plus the unit has a small dial switch that allows selection of 9 different timing advance curves and timing. It also has a built in rev limiter – selected on a two position switch – and a take-off for a tach.
The unit has been used for my last four races and I can report it has performed faultlessly. I also went on the dyno and ran through the 9 ignition settings to establish a range of power/torque settings that would suit different circuits.
Volker Sachse is the gentlemen who supplies the units and is very good to deal with.
You can see more details by visiting his web site http://www.elektronik-sachse.de
Best wishes
Eric Pritchard

[wcorey]

Looks to be pretty comprehensive in features, can't say I can think of anything else I'd want to add.
Would be interesting to play with all those advance curves.
Was there a noticeable difference in performance between different advance curves that start/end at the same points (like #'s 4 and 5 for instance)?
He doesn't specifically say what impedance the coils can go down to, I wonder if it would be ok at 1 ohm?
Does the sensor trigger it at hand turning speeds?


Bill

[DewCatTea-Bob]

____ All posts within this new thread are of course very much appreciated,
but I believe this topic has already been brought-up within other similarly titled threads, (not to say that this particular subject-mater had already been covered!).


" I also went on the dyno and ran through the 9 ignition settings to establish a range of power/torque settings that would suit different circuits. "

____ All this would certainly be of utmost interest, if our Duke-engines could make any beneficial use of automatic ign.advance curve-adjustments between getting started & top/max.RPM !
However since any of these varying adv.curves are likely all-done, (please correct me if I'm wrong), by 3k-RPM,, then any of their possible differences (either between each other, or the stock-curve), ought to be pretty-much of very little use !
__ It would be fairly interesting to see all the dyno.testing-results for comparing all the slight power-output variances between those 9 varied ignition-settings ! _ But I much suspect that all that wouldn't really be worth bothering with, as (I figure) the max.difference (between which-ever two adv.curves that happen to provide the greatest difference between them), would likely amount to less than 1/2-HP, (from a 250, anywhere under 3k-RPM) !
__ Also, once the particular adv.curve-setting with the very-best results has been determined,, that same setting ought to remain the best, no matter what the type of race-circuit !
So for any others who choose to employ that same ign.device,, it would then be NICE, if that best-setting were to be shared here, for others to then avoid the related dyno.test-work !
And since the small difference in power-output within that limited RPM-range is certainly no big-advantage,, there's thus really no racing-advantage to be retained, by keeping that helpful info to one's self !
Besides, any good Duke-rider/racer ought prefer to win his races against same, by his rider-style/racer-abilities, rather than a power-advantage, (right?).


Hopeful-Cheers,
-Bob

[wcorey]

Bob, I assume you didn't look at the graphs on the site? Some of the curves (8 and 9) have a 2 or 3 degree difference up around 5000 rpm, and some differ in start/end points by as much as 6 degrees. But yeah, for racing in mostly the upper rpms, it would seem not as important as on the street.



Bill

[DewCatTea-Bob]

" Bob, I assume you didn't look at the graphs on the site? "

____ True... I had clicked on the supplied link but, it didn't take me to that more relevant page, and I didn't care to spend any time looking-around in hopes of possibly finding such.
__ How about including a link to that interesting & more relevant page ?


" Some of the curves (8 and 9) have a 2 or 3 degree difference up around 5000 rpm, and some differ in start/end points by as much as 6 degrees. "

____ Wow, now that's more impressive !
However, (even though I've still not seen any dyno.results), I'd bet that there's still less than 1-HP difference between any of those fancy adv.curve/settings and that of the stock set-up !


" for racing in mostly the upper rpms, it would seem not as important as on the street. "

____ True but, I suppose for any race-circuits which require a fair number of 1st-gear turns, such diverse ign.timing settings might supply a particular setting that's able to offer/provide some kind of slight advantage (from each of the others, or stock). _ But of course since there's still no trade-off advantages between that which is best for the lower RPM-range & that for the higher RPM-range,, once the best adv.curve/range-setting has been discovered, the type of race-course/circuit shouldn't make-case for any other/different setting.


Dukaddy-DUKEs,
-Bob

[wcorey]

__ How about including a link to that interesting & more relevant page ?

Hmm, the link won't go directly to the applicable page, you need to click Digital ignition on the upper right, then Technical under that.

http://www.elektronik-sachse.de/index_en.htm



Bill

[DewCatTea-Bob]

" the link won't go directly to the applicable page, "

____ Thanks for your helpful directions Bill !

____ I'm copying those graphs to be posted here.
They used three graphs to show their 9 adv.curves, and on their graph which had the least plots, I've added 2 additional plots of my own...
__ Since it seems they offer customized-adv.curves, I thought it could be helpful to also show the adv.curve-plots which ought to be best for the 250 & 450 Duke-engines. _ (I didn't bother with an extra plot for the 350, as the average between the two [added plots], ought be suitable for it.)
__ For the recommended adv.curve-plot for a 250 - it begins at 4-degrees BTDC @ 800-RPM, then climbs to 35-degrees BTDC @ 3000-RPM -(pretty-much the same as a stock Mach-I), and continues-forth to 38-degrees BTDC @ 3200-RPM -(which is a fair compromise onward-towards the 41-degrees BTDC max.advance of the 250Mk3).
__ For the recommended adv.curve-plot for a 450 - it begins at TDC @ 1000-RPM, then climbs to 28-degrees BTDC @ (just after) 2900-RPM -(pretty-much same as stock), and continues-forth to 32-degrees BTDC @ 3200-RPM -(for improved max.power over stock).
__ I would expect that even steeper rates (up-to max.advance) would be better than any of the 9 adv.curves offered as presets. _ But if ya prefer to trust the (expected to be) experts, then which-ever of their adv.curves comes closest to that which I've plotted, (once properly adjusted for stock static-timing), ought be the best choice of their 9 offered presets.


Mod-Cheers,
-Bob