OK I have tested the latest version on my engine sim an dusing a timing light the curve that is supplied with the code is no good. at 200 rpm the curve is below tdc and max advance is never reached. To me the curve should be at 5 degrees from 200 rpm upto 1300 or so. Then advance the timing with rpm upto 4000. from 4K and up max advance should be obtained. I know I will have to play with the spreadsheet.