<VV> Aftermarket Coils Re: follow-up on bogging down, sputtering

[FrankCB]

Mike,
     Good point!  But I didn't say to ALWAYS bypass the stock ballast resistance used in the stock setup.  Instead, follow the mfrs instructions as to whether or not to use the ORIGINAL STOCK ballast OR to install a NEW one of a certain resistance.  The point I was trying to make was to consider the ENTIRE setup including all the wiring to and from the primary side of the coil.  This is especially true if you're using an electronic replacement of the stock ignition points.
     Frank Burkhard  

In a message dated 08/17/09 22:06:50 Eastern Daylight Time, vair65 at sisna.com writes:
frank-disagree. the allison coil which i'm replacing with a msd both use ballast resistors. msd uses a .8 one while the allison was more. both are 45,000 volt coils-mike mann


On Mon, Aug 17, 2009 at 6:13 PM, FrankCB <frankcb at aol.com> wrote:

Dennis,
    I agree that the stock coil should be good enough for the stock (unmodified) engine. Most of the aftermarket coils are lower resistance than the stock coil and therefore will TRY to flow higher-than-stock current but ONLY if they have a full 12 to 14 volts present at the positive terminal.  This higher current can cause significant voltage drop especially if the stock resistance wire is not eliminated.  Even if the resistance wire is bypassed, the higher current through the stock wire from the back of the car to the front, through the old ignition switch and returning back to the engine can cause significant voltage drop so that the voltage at the coil + terminal is much less than 12 volts.  The coil is really a transformer so it multiplies the voltage in the primary to make a much higher voltage in the secondary that ignites the combustion through the plugs.  But if the primary voltage at the coil + terminal is way below 12 volts (due to excessive drop) then it's possib
 le the sparking voltage may actually be BELOW the normal STOCK sparking voltage from the stock coil.  So it's important to make sure you have the correct voltage at the coil when the engine is running no matter what coil you are using..
    Frank "sparky" Burkhard



In a message dated 08/17/09 16:25:42 Eastern Daylight Time, dpleau at wavecable.com writes:
I went through three aftermarket coils in a short period of time.  One
Pertronics and two Accel before I went back to the original.  All had the
exact symptoms Ernie had.  That's why I suggested his problems was the coil.
All three had the right resistance both before and after they started
causing problems and they were hooked up properly.

Dennis