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Mike Lawless
09-10-2003, 12:09 AM
I have a 1950 lb aircooled VW running mid 11s using a digital 6 with a MSD billet distributor. Shift points are at 8200 and it goes thru the traps at 8400 rpm. My concern is that I may be past the boxes limit as I seem to get some "flutter" just before the shift points. The car is equipped with electronic fuel injection which gets its trigger from the tach output on the MSD. Secondary wiring is new (MSD 8.5) and routed nice and the trigger wire from the distributor is routed well clear of the secondary wiring.

msdtech1
09-10-2003, 11:42 PM
The Digital 6 should be ok for what you are running, but I need to know a few more things before I answer your question. Is the engine missing (futtering) as you are going through the traps at 8400 rpm? What is the compression ratio of the engine? Which coil are you using?

MSD Tech 1

Mike Lawless
09-11-2003, 12:20 PM
The "flutter seems to come in as the motor passes 8000 rpm, both as I'm approaching the shift point and approaching the traps. The compression is just under 14-1 and I'm using the MSD Blaster SS coil. Sometimes the tach needle will jump and the shift light will come on at the same time as flutter, well before the shift light is set to come on. Again, the secondary wiring is new, MSD Heli-core 8.5mm, and the pick-up wires are routed well clear of the secondary wiring. Spark plug gap is .040. I also have an RPM activated switch to trigger the retard to back the timing down from 32 degrees total to 30 as the motor goes past 7800 rpm. It does NOT like that at all, so I don't use it. The selector dial for that is simply set to ZERO at this time.

msdtech1
09-12-2003, 12:02 AM
If the tach is jumping around when the flutter is occuring, that means that you either are having a secondary, ie cap, rotor, coil, coil wire, spark plug wire or spark plug breaking down, or you are not able to jump the gap across the spark plug with the current voltage available at the plug. As a test, reduce the gap down to about .020-.025 and make a run to see what occurs. If the problem is reduced or is elliminated then if you want to continue to run a large plug gap then you will need more ignition. You did not mention what type of fuel you are running - gas or alcohol? If you are running alcohol I would definately step up to a hotter ignition at this time.

MSD Tech1