Re: TFI and HEI what\'s the difference?
"""""MSD delivers around 1,000% more duration of spark, the actual time the spark lasts in the gap of the plug.
Since the HEI's spark duration is 2.25 MS - then 1000% longer would mean 2250 MS, or 2.25 seconds long. Hopefully the engine turns faster than that.
MSD has it's advantages yes, but not that much.
The "multiple" spark stops being "multiple" at about 2000 RPM. It "runs out of breath" at about 6000 RPM, about the same as an HEI. Use a distributor machine to compare.
Even the MSD website admits it.