MSD Coil replacement
My boss once did a test on a GM coil vs an MSD coil and in that particular case, the results were a bit different. We monitored both the coil current draw and the secondary voltage. This test was done with a variable dwell angle HEI module, so you would get a different curve with a Mopar system, but I'd expect the same trend.
The MSD coil drew more current across the board. So this coil would give you more spark energy at idle and at the top end. However, this engine didn't really like to rev out very well, didn't make a lot of cylinder pressure, and so it didn't really have any need for a hotter ignition system. I don't expect any problems with the coil upgrade here, but whether you will benefit depends on what mods you have.
The voltage is definitely one of the key reasons the boxes use a different coil. However, it's the box, not the coil, that underperforms at low RPM. A CDI box's spark does not burn as long as a stock ignition, so it compensates by adding more of them.
Good point, oil filled MSD coils should never be installed sideways. I've seen one self destruct when installed upside down and the oil leaked out.
My boss once did a test on a GM coil vs an MSD coil and in that particular case, the results were a bit different. We monitored both the coil current draw and the secondary voltage. This test was done with a variable dwell angle HEI module, so you would get a different curve with a Mopar system, but I'd expect the same trend.
The MSD coil drew more current across the board. So this coil would give you more spark energy at idle and at the top end. However, this engine didn't really like to rev out very well, didn't make a lot of cylinder pressure, and so it didn't really have any need for a hotter ignition system. I don't expect any problems with the coil upgrade here, but whether you will benefit depends on what mods you have.
The voltage is definitely one of the key reasons the boxes use a different coil. However, it's the box, not the coil, that underperforms at low RPM. A CDI box's spark does not burn as long as a stock ignition, so it compensates by adding more of them.
Good point, oil filled MSD coils should never be installed sideways. I've seen one self destruct when installed upside down and the oil leaked out.