Ballast resistor or not?
- Thread starter Seca900r
- Start date
-
1wild&crazyguy
Banned
one ohm with mopar ignition, on no resistor with msd box, it internally controls that part.
dgc333
Well-Known Member
I believe the MSD recomended ballast resistor is 0.8 ohm.
dgc333
Well-Known Member
FYI, its not so much as controlling it as the MSD works completely differently and its not applicable.
In a point or basic electronic inductive ignition the dwell (or time that current is flowing through the coil) is approx 30 degrees. On an 8 cylinder engine for each rotation of the distributor current is flowing 240 degrees of the 360 degrees of rotation or 66% of the time. Current flowing that much of the time will over heat the coil and cause it to fail. The ballast resistor limits the current flow to protect the coil.
An MSD box charges a capacitor and discharges it across the coil. The discharge happens in milli seconds but at a very high voltage (400 +). Becuase it happens so fast the coil never has a chance to heat up enough to cause problems. Because it happens so fast that there is enough time to do it three times per ignition event below 3000 rpm.
brkooduh66
Well-Known Member
read your wire schematic: ballast resistor. when the ingition switch is in the start position the resistor is byepasted to give the coil 12V for start-up. when the ingition switch is in run position the resistor is put in the curcuit to reduce the voltage to 6V. (or to whatever voltage the system is designed for). put a volt meter on some things to verify
bremereric
Well-Known Member
My MSD ignition runs with the ballast resitor just fine...however I believe the installation instructions said no external ballast resistor is required
blmopar1
Well-Known Member
Sorry not to but in, but suppose you are running a msd dist.,blaster 2 and a6al box do still need to run a ballest. Thanks
demon seed
The Original Demon Seed
Usually no. If you're running a Blaster 2 coil, or anyones coil for that matter, on a Mopar system (eg. orange box) then yes.
-
