ignition output voltage vs. spark energy

[virgostang94]

What aspect of aftermarket ignition's should you be more concerned with the ignitions output voltage or the spark energy measured in millijoules when coupled with the coil???

 

[virgostang94]

msd vs. crane ignition

The MSD digital-6 ignition claims 535V power and 135 millijoules of spark out-put. Crane Cams Hi-6R claims 450v power and 1,200 millijoules of spark out-put. What is more important spark voltage or current so to speak.

-Steve-

 

[tmoss]

millijoules is the better measure - it relates to the total heat released in the spark.

 

[virgostang94]

I'm convinced that current is more important than voltage because you can have 10 million volts at the tip of the spark plug but it isn't going to jump across that spark gap with out current. Therefore I would rather buy the ignition that has more millijoule output than voltage.

 

[stang_gt_1994]

After high voltage is created in the coil your not going to have many amps anyway, like 0.00175A with a 8000 ohm secondary reading.

 

[tmoss]

In a spark gap system like a car ignition and spark plug, the voltage developed is self limiting. The voltage rises when the coil fires to the point where the air between the electrode and the ground strap on the plug is overstressed and the air/fuel ionizes until the voltage jumps the gap. At that point the voltage (like water pressure) has been building up, but once the plug fires, the voltage "potential" (pressure) is turned into current and the voltage drops as current rises.

 

[virgostang94]

You got your milliamps wrong...

175 milliamps equals .175amps.

 

[virgostang94]

ohms laws says: current is proportional to voltage. I=current, E=voltage, R=resistence. If "E" is equal to "I" times "R" Then if voltage increases then current either current or resistence had to have increases. Resistence is set. it doesn't change whatsoever. SO THE BIG QUESTION IS "WHAT IS BETTER HAVING MORE VOLTAGE OR MILLIJOULES OUT OF THE IGNITION???

 

[virgostang94]

Electronics Technician in the house... What about you.

 

[squall9393]

millijoules is the better measure - it relates to the total heat released in the spark.

I second that. You want a hotter spark to burn the mixture. Voltage is "electromotive force" that causes the current to overcome the sparkplug gap. the voltage is gonna be stepped-up by the ignition coil anyhow so when your in the 5 digit range of voltage I would think one is as good as the other. If I take a rock and throw it over a gap in the road and then take one and throw it with harder force- yes, it will get there faster. Same with increased force (voltage)- it will overcome the restistance of air in the gap of the sparkplug electrode more efficiently. All this can be compensated as well by shortening the spark gap if you want a smaller gap to overcome and a hotter spark. My 2 pennies.

 

[virgostang94]

I work around high voltage and also high current electronics. I've seen idiots get shocked way more doing stupid things around high current electronics.

 

[virgostang94]

Hard facts finally.

After a little while searching the web I came across this site with dyno proven numbers. and It's just what I expected.

http://www.4wheeloffroad.com/techarticles/53778/index2.html

 

[virgostang94]

millijoules per spark in each 20 degree crank rotation.

So If crane cams says their hi-6r ignition puts our 1200 millijoules and msd's digital-6 say's their ignition puts out 135 millijoules per spark. is crane cams advertising the total millijoules added together in their total spark duration??? Meaning crane cams hi-6r ignition puts out a max or 12 sparks in one 20 degree crank rotation for spark up to 3000rpm's equaling 100millijoules per spark???

 

[virgostang94]

vote in the poll for the better ignition module.

CRANE VS. MSD

HI-6R VS. DIGITAL-6

 

[virgostang94]

-test signature-

 

[squall9393]

Holy cow virgostang94. That was like 5 posts back-to-back. So what's up yo come to conclusion yet? If you want, start a poll thread MSD vs. Crane. BTW you stole wytstang's avatar. He has the same one. Got confused there for a sec on who's who.

JJ

 

[JJ95GTID]

Mallory HyFireVI series is a good choice too from what I have read.