Electronic Distrubuter Tricks

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highwaystar

highwaystar

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I was thinking of posting this on the racers forum, but it looks like they have bigger fish to fry. From a little over stock motor with a larger cam 262/268-475/494 lift. Anyone have suggestions with a stock mopar Performance dist. Years ago I could remember stretching the heavy spring or trading it out for a lighter one all together and pluggin the vacumn advance for it to come in quicker. Any better ideas out there. Gas mileage is not a big concern. looking for performance.
 
I have always had good results trashing the heavy spring and putting a light spring (mp or mr gasket I thing it is) and unhooking the vac advance. With a small block I set the timing at 35* total and big block at 38* total at about 2200 rpm. Usually my initial works ok but depending on your dist you may have to open or close the advance slots for your needs.
 
Don't unhook your vacuum advance, unless you like sluggish part throttle responce and losy fuel mileage.
 
You mentioned you have a "stock Mopar Perfromance distributor", if it was manufactured after 2002 it will have Mallory guts that includes an adjustable mechanical advance as well as the adjustable vacuum advance. There is also a kit which includes several sets of springs and a set of spacers for setting the mechanical advance it's available from Summit or Jegs and is Mallory part number 29014.

Also, if it is a MP distributor it will already have light springs in it so there is not need to to muck with them unless you start limiting the amount of mechanical advance so you can run more initial then you will likely need to go heavier on the springs to keep the all in point in the 2500 rpm range.
 
Here's a good article on timing: http://www.jefframin.org/library/distributorRecurving.doc

Here's an excerpt from "Tuning to Win" written by Don at FBO (Ignition):

We believe that most Full Race Engines do not need a vacuum advance type distributor or what we refer to as a Stage 1 distributor.
The vacuum canister reads constant manifold vacuum and as the vacuum
increases it gives more timing to the motor. This is all fine until you slap the
throttle down, in most performance engines the piston can increase speed
dramatically almost instantaneously, the vacuum diaphragm can’t release the
timing quick enough and you’ll get instantaneous detonation...not good. You
may not hear it over your exhaust but it's there and it will damage the engine
eventually. Any medium or hot street performance engine will see great
improvements in Idle quality and drivability from using a vacuum controlled
advance unit. Non-Vacuum distributors are for RACE Cars not Muscle Cars and
have a very specific application and in most cases are wrong for any street
driven car.
 
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