Originally Posted by STODD

I installed summits version a few weeks back. I do notice a quicker start, but I also notice that it miss fires in midrange real bad. It is to the point where it makes the car jerky, even at 55 at 3500 rpm. When I go wide open it is fine, and it don't seem to skip a beat.
The main reason I bought it was the rev limiter, I have issues with 2nd gear and don't want to scatter this new motor. I am thinking gkull was right and I now have too much juice for my 8mm accel wires. Running it in the dark tonight I could see the plugs glowing some and a pretty bright light out of my HEI where the + and- wires connect to the coil.
It also makes a racket inside the distriburtor, I heard the MSD boxes were loud, my box is quiet, but the distributor sounds like it has a mini gear drive in it!! It is a new distributor and I took it back apart and found nothing obviosly wrong.
I was impressed that it was made in the USA, I wonder if the MSD unit is.
Any other opinions on the mid range misfire?
Motor is a S/B 406 with a com 306s-10-.306--.555 solid flat tappet and has a grumpy idle anyway, but this mid range thing is new since installing the box.

Originally Posted by MotorHead

And yet everyone has one

To the original poster NO

Originally Posted by gerry72

Is there an advantage? Notwithstanding other comments, yes, there can be. A piston engine will always suffer from cyclic variation. This means that conditions in the cylinder are not entirely consistent from combustion event to combustion event. One thing that does occur is sporadic and random misfire. This is usually due to a mixture vaporization anomaly. This isn't something you'd easily notice, like a consistent misfire. What a multi-sparker does is to keep hitting the plug in hopes of recovering a successful combustion event. It can give you a smoother idle.

But the 6AL is pretty dumb and the digital boxes are not much smarter. It hits the plug whether it has fired or not. And as noted above, it does this only below 3k rpm. There are other more sophisticated systems. Jacobs, before they went south of the border and started building less stellar products, did make a fairly expensive system that would send a follow up pulse to the plug to sense the ionization in the chamber and if it sensed combustion did not occur, would hit the plug again.

The other thing the 6AL (and other CD ignitions do) is instead of building the voltage rise in the coil through induction, the coil is just a transformer where the capacitor discharges into the coil where voltage is stepped up. This changes the ignition characteristics from the inductive's longer spark duration to the capactives higher rise and potential voltage. In most cases, this is really irrelevant. If you have a difficult to fire mixture, it can make a difference.

But if your engine seems to be running fine with what you have, there's not really anything to gain by going to MSD's or anyone elses box.

Originally Posted by snoopykissedlucy

I say put it in or give it to me!

Again, wives like easy to start and evenly idling cars. Us guys don't mind a rough idle, and actually prefer it....

The MSD will idle smoother than a stock..........based on my personal experience.

Originally Posted by STODD

Thanks gkull,
It seemed fine at the strip, but for a cruise it stunk. Not sure if it is getting worse or not. Hoping to hit the strip again this Friday night, so I need to order some wires or disconnect it, but like you, I need that rev limiter.