Hey guys something interesting for thought,

just for kicks cause i was bored i chucked the strobe light onto the old coil of my bike and had a look at what happened. it should seem that the BZM based coils retard the spark by up to maybe 10 degrees or so as RPM increases where as the stockers seem to be pretty well locked in place through the rpm range.

am thinking of toying about with a 5 degree timing key to bring up the low end power a ton and retain the top end. will have to search up on a bit more info on this IDM coils

you cannot change the timing of the spark, race rules

lol i guess we'll all have to be removing our bzm coils trying to work out how to get a damn video of the thing, but it doesnt seem to be working

AFAIK,

There was no issue adjusting the timing..... you just were not allowed to use digital ignition

There should be no problem using an offset woodruff key to advance/retard the spark.

nith's 2c

	Glen wrote:
	lol i guess we'll all have to be removing our bzm coils trying to work out how to get a damn video of the thing, but it doesnt seem to be working

Yor video will not work too well. It is similar to videoing your TV. The images 'flicker' at a minimum of 25-30fps (quick enough for the human eye to trick the brain to 'see' fluid motion) and the video camera is designed to be compatible. Your engine and strobe will be 'flickering' much faster than that. (even at 6000rpm you will have 50 sparks/s). Try a high ISO setting with a digital camera. Most new ones can do about ISO1000 equivalent I think (the highest for film is ISO400) and set it to continuous shooting at the highest frame rate available (this still may not be high enough). ISO is the (film) rating where the higher the number the quicker the film can absorb light from the camera aperture. Good for high speed or sport action to avoid blur. For digital cameras this is electronically mimicked and hence an ISO of 1000 is possible.
Maybe some photograph/video phile can add/correct this description.

john is there anything you dont know smart fella

	Nith wrote:
	AFAIK, There was no issue adjusting the timing..... you just were not allowed to use digital ignition There should be no problem using an offset woodruff key to advance/retard the spark. nith's 2c

i think from a meeting there was a rule for no changing of the timing

	barnsey22 wrote:
	john is there anything you dont know smart fella

Just a closet nerd matey

Glen wrote:

Hey guys something interesting for thought, just for kicks cause i was bored i chucked the strobe light onto the old coil of my bike and had a look at what happened. it should seem that the BZM based coils retard the spark by up to maybe 10 degrees or so as RPM increases where as the stockers seem to be pretty well locked in place through the rpm range. am thinking of toying about with a 5 degree timing key to bring up the low end power a ton and retain the top end. will have to search up on a bit more info on this IDM coils

You are correct Glen - the Polini/Ducati/BZM coils are 'electronic'. They have some electronic componets (inbuilt transistor/capacitors/resistor/diode) configured to alter the spark advance at high and low rpm. At low rpm there is plenty of advance and at higher rpm the timing is retarded (in order to optimise) cylinder filling. I know that some will say that advancing the timing at higher rpms is a way to gain power, but if you only fill half the cylinder before ignition (advanced), then you actually lose power and blow out fuel straight out the exhaust port.
The standard coils on Banshees and early model Blata's have a fixed spark interval. This is why you can also gain some power from your rep engine by changing the coil. However, some flywheels are not so compatible (the magnets' length and position) and keyway are located differently.

you can change & set your timing to what ever you want hardcore you just cant have an ignitionsystem that is a programable (i think)

mmmmmmm, programmable ignition.........how sweet would that be??????

actually now i think about it there is no programable ignitions allowed just the fixed type, but in saying that i he standard bzm, polini type coils are changing then are they legal ? that may meen a re think of that rule to open ignition's

	Bollins Racing wrote:
	actually now i think about it there is no programable ignitions allowed just the fixed type, but in saying that i he standard bzm, polini type coils are changing then are they legal ? that may meen a re think of that rule to open ignition's

again in english please i dont quite understand what your on about ..how do these progamble ones work and how much of a diffrence do they make

The coils are not programable, nor are they outside the rules. They are 'hard wired' i.e. with solid state electronics and are designed to do this. The spark advance/retard is determined by the revs and the selected electronic components. The cheaper copies are 'fixed' i.e. they only have a primary winding and a secondary winding (which delivers the high voltgage required to 'jump the gap') and no electronic components. I think Giannini has a system running which can alter the spark advance/retard. You can achieve this by having an external dial or similar which can alter the bias current required for the transistor base with a variable resistor? I haven't looked at the circuit in detail, but it is simple.
This is also why after a heavy crash, some engines may fail to run due to the coil being 'damaged' ie the electronic components have broken their electrical connections by the heavy shock. This happened to me a few years ago at Indy after a big crash (some may recall that crash with a new RR).

	GRCmoto_Australia wrote:
	This happened to me a few years ago at Indy after a big crash (some may recall that crash with a new RR).

any footage ?