This is pulled in from another thread, where we were wandering off the topic
I have followed Dave's thread about the regulated IC setup. I find it very interesting, but I don't think it will work. Not because of anything you did, but because of the way IC engines behave. I don't think they can change rpms fast enough to get the timing right, unlike electrics which can change rpms immediately.
Nothing can change RPM immediately. The electrics may be able to change RPM faster than engines set up the way we're used to, but they're still taking a finite amount of time to change RPM. The question is whether engines do, or can be made to, change speed quickly enough.
I don't have a lot of good data on engine response, but here's what I do have. If you squint at the plots, you can see that the engine acceleration and deceleration starts with a sharp, quick speed change, followed by a more lazy increase or decrease in speed. I suspect that the slow engine response you perceive when you goose the throttle on a plane is that latter part, while the initial burst may be all you need.
I also suspect that there's room for improvement on throttle response, either purely with how the throttle is treated by the control system, or with changes to the engine and/or carburetor. It's pretty well known in full-scale automobile performance circles that when you go for all-out horsepower in an engine you pretty much throw quick throttle response at anything but a narrow band of engine speeds into the toilet. Engines built for racing classes that involve going around corners a lot often get built with smaller passages in the manifolds, smaller carburetor bores, and specific cam timings for exactly this reason. I'm not nearly as up on 2-stroke engines, but I'm sure the same principles apply there.
So I haven't written off the notion of controlling an engine with this stuff, but I'm not going to bet money that it'll pan out, either.