Ignition Controls, MSD 6A

[Ron61]

I use the Jacobs Pro Street now as it is a great unit I think. I can just wire around it in a minute if the unit goes bad and not have to make any changes. Also set the rev limiter in 100 RPM increments with a small screwdriver. Two adjustments, one for 1,000 RPMs and one for 100 RPMs I have never used the new MSD unit, but did use older ones and I prefer the Jacobs because of ease of changing in case it goes bad, plus it has a variable resistance coil which lets it put exactly the amount of juice to each cylinder that is needed to make them all fire the same. It measures the resistance to each plug and may put 80K volts to one and 75K volts to another if the resistance is less, hence you get the same combustion from each cylinder. I have disconnected it and ran it just off the coil and distributor. I use an inductive MSD distributor in one car and an Inductive Mallory distributor in the other. When I ran them just off the coil and distributor, I could really feel the power loss and also they loaded up really bad at idle. But I am sure the newer MSDs are just as good with the exception of ease of running if the box goes bad. I used to carry a spare MSD box with me whan I was using them and if one went bad I just disconnected it and put the new one in place.

Ron