How can I design a spark ignition system with a wider energy delivery range?

[mfig]

Hello,

I would like to design a spark ignition system with a wider range of energy delivery than a typical MSD system. On the MSD systems I have looked at, they are limited to about a 10 mJ range, but I need to go from, say 5 mJ to 1 J if possible. Does anyone know of a packaged system like that or how to modify an MSD system to deliver a wider range?

Thanks

 

[jim hardy]

here's an interesting project, a meter to measure spark energy.
If you're "hopping up" factory systems you'll need a way to quantify results.
http://worldphaco.net/uploads/THE_SPARK_ENERGY_TEST_MACHINE.pdf

1 joule per spark X how many sparks per second ?

How do you plan to power it ?
8 cylinders @ 8000 RPM X 1 joule/spark = 32000/60 joule/sec = 533 watts = 44 amps@12 volts

 

[Averagesupernova]

When I worked in the aftermarket automotive electronics industry I recall reading that the typical HEI ignition system that GM used for many years was about as much spark as anything typically needed. Any more energy beyond that showed no gain in performance. Now this is of course up for debate and I am just repeating what I have heard. I will say that how 'performance' is defined is also up for debate. I have an MSD system on a car and I suspect that the multiple discharges improves starting and in my opinion this is an improvement in performance. I didn't do the math that Jim Hardy did but if you draw 44 amps from your electrical system do you think maybe the power it takes to supply this spark will load the alternator to the point that you are in fact losing performance?