sportage4x4 wrote:The LT1 ecu does not use the 360 slots for anything critical. It is used to calculate engine speed at and just above idle speed so that the idle speed stabilization routine can react quicker than simply waiting for the long slots. It does not compare the edges of the 360 slots with those of the 8 slot track. It does, however, use both edges of the 8 slot windows and can sync sequentially within 180 crank degrees.
That does tally up with the fact that the "broken" MSD optis will work with it, but also seems rather perverse. What's the source of your information? How authoritative is it? The LT1/Opti information that I've read makes big of the high-resolution of the CAS that can reduce spark scatter which _suggested_ that the hi-res track was being used.
As found earlier in this topic my code does seem to work ok with OEM Optis, but not with the MSD ones. It seems a shame to through away the hi-res information although from what I've seen all(?) other aftermarket ECUs ignore the hi-res slot.