You're right Fank. When I wrote my post I was thinking the whole time about the 'barn door' style MAF that I have. Once the door is wide open under high load that's it, additional air flow will not effect the signal to the ECU and so the mixture would lean out. Since it's NA this won't happen, but if I stuck a SC or turbo on there with >7-9psi of boost that could happen. However, a hot wire style MAF (is that what the stealth engine has?) may operate differently, but won't it will still have a limit in the amount of air flow it can measure?

The other issue is the Miata engine is a turbo engine made NA. It has strong internals and oil cooled pistons. May be the Stealth engine is the same, I don't know. In any case and air/fuel ratio gauge and/or a knock sensor may save the engine if this is going to be an experimental project. I've been thinking about a Megasquirt unit (looks like fun) and I think you're right that a 'piggback' unit to retard timing under boost won't be too difficult to tune. I have heard that the stand alone units are much more involved but quite doable. Having said that an MSD timing retarder unit would probably work well too.

Like I said I'm no expert on this, but we have probably all heard about DIY FI projects resulting in a blown engine. May be a 3000GT/Stealth forum would be helpful in determining what the engine can handle, unless you all already know that <img src="/forums/images/graemlins/pfft.gif" alt="" /> and I just talking out of my...