I have a Lexus IS300 for which I'm engineering a Supercharger system to boost output of the 2JZ-GE inline 6-cylinder 3.0L engine. Arduino Mega is serving as the engine control unit to retard ignition timing, scale fuel injector pulses, and modify the oxygen sensor output providing for proper closed-loop fuel management from the stock ECU.
Much thanks to the community here for helping me get to this point.
I've started building a blog with details that I think now has enough content to be interesting to others. I'll be posting more info relatively quickly, including more source-code.
Interested readers can find more information here...
http://thedeltaecho.wordpress.com/2jzduino/
Comments, questions, and discussion wanted

Just hoping to share some information that others might find useful.
-MDH