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Re: 60-80 times and electronic ignitions

As to 60-80 times:

I floor it at 55 and run the stopwatch from 60-80, as per Jim Rowe's method
at MM.  My times are very consistent with the graphs he shows for various
motor/car setups.

For us older-car owners, electronic ignitions in all their various guises
(Allison/Crane, MSD, Pertronix) are very appealing.  However, I had a real
problem with one and would like to know if anyone else has a similar
experience...

I put an Allison unit (essentially a points replacement with perhaps "a
little bit more", but certainly not an MSD) on a '77 530i. The spark
quality was great - nice blue arcs jumping over 3/8".  I was impressed. I
didn't have any reliability problems, etc.  HOWEVER, after a lot of careful
tuning & testing I discovered that my motor's reluctance to rev at high rpm
at full throttle _WAS DIRECTLY TRACEABLE TO THE ALLISON UNIT BEING
"IN-CIRCUIT"_. Once I returned to conventional points the problem went away
_completely_.  I admit I didn't try another Allison unit, but I had no
reason to believe mine was defective.

This is my suspicion - that the Allison somehow messes up the 530i's
Jetronic brain and prevents it from delivering enough gas in the high-rpm
operating range. Recall that L-Jetronic drives all the injectors from a
signal derived from the points. Perhaps the Allison requires too much
juice, more than the Jetronic brain can supply to the distributor
terminals.  The tach does not misbehave, though, so I can't conclusively
say that this is the problem.  Any ideas?

Andrew