Any progress on your project?
I've been following Speeduino along since 2014 with similar goals but haven't done anything with it yet. Personally, I was inspired by Robert Haines work and thought a Speeduino fork might be a better starting point than rolling my own: http://www.hainesengineering.com/rhaines/
Let me know if you need any help; I've been doing open source tuning since 2008 and aviation stuff even longer. Just don't have the time to work in the hangar these days.