Altering Ignition Timing via CAS signal manipulation

[GARY]

Well, the title should explain what I'd like to accomplish.  I would
like to manipulate the electrical signal coming off of my crankshaft
angle sensor to affect a change in my ignition timing from what the ECU
would normally have it offer.

My 98 Subaru Legacy 2.2 Liter has a magnetic crank angle sensor.  This
is called a Hall Effect Sensor, right?  Anyway, it reads one or more
rotating protrusions of metal on the crank shaft pulley.

I am assuming that all four spark plugs fire each time a given cylinder
charge ignites.  So I am assuming that if I delay the signal by, for
example, 99 percent of the time between pulses that I would be
effectively advancing timing by 3.6 degrees since it would be firing .99
x 360 degrees late.  Right?

If so, how can I build such a device and make it adjustable.  

In the archives I saw there was a guy in Australia trying to do
something like this to a Commodore (sp?) and he was refereed to using
some piece of equipment out of a 77 Toronado or a 198x chev. truck.  Is
he listening, did he get it accomplished.

Has anyone done this sort of thing and am I out of my mind?

Thanks all! 
-- 
GARY       mailto:hobiegary at earthlink.net