Originally Posted by 55 Tony
It's not what I saw. That goes in place of the vacuum advance, which I'm not using right now anyway..., also it's made for an HEI distributor but I suppose if it needed adapting I could make it fit? The one I saw turned the distributor.
Does anyone here street/strip race? What do I do if when it's advanced for the most HP (seat of pants anyway) it has a little ping at part throttle? I tried slowing the advance curve and that really took a toll on the seat of the pants dyno. I haven't had time, but I may try making that part throttle area a good deal richer and see what happens? Even on the street, I'd like to be able to punch it and really feel it like I know it has the ability to do.
If you've got a part throttle ping without any vacuum advance, then you are in dangerous timing territory. You can always read the ground strap on the spark plug for proper timing. Are spark plugs burning clean (hot enough to burn the carbon off the porcelain)?
You can always get a MSD or Daytona Sensors box, lock out the distributor, and do the centrifugal advance and timing adjustments electronically through a timing table. Planning to be able to adjust timing for weather conditions this way. I have Daytona Sensors ignition on a MSD small cap vacuum advance billet distributor. Note there is a limit to the amount of spark retard you can apply relative to your reference timing (where it is actually set). It's around 20°. You can even keep your vacuum advance if you so desire (while centrifugal is locked out). Daytona Sensors ignition box allows you some basic data logging as well.
So the way it works is you set your centrifugal locked distributor to say 38° without any spark retard. Then you build a timing table to take you from 18° at idle to maybe 36° at 3000 rpm, with any curve (linear or otherwise) in between. Best to leave a couple of degrees between reference and max timing, so box has time to respond accurately - remember first the reference signal happens, then the box calculates delay based on the program and fires the coil. If you use the vacuum advance, it adds to whatever timing curve you have programmed. I leave my vacuum advance unplugged because its a strip only vehicle. My plans are to simply electronically limit the max timing to different values (for example 34°, 35°, 36°) to account for different weather conditions by downloading a different timing program.