I do not think anyone could answer those questions as you wrote them.

Way too general IMHO. I think you already pointed that out in your post.

T3/T4 can be many many diferent turbos. That is almost like saying my car has a 4 cylinder, so how much power am I making. Only you are talking flow rates and different psi levels/rpms. I really think this subject is better for a different topic.

All fuel/ignition control systems are piggy back in their nature. If they retain the stock ecu, then that is what you have.

There are quite a few engine management systems on the market, but nothing works as well as a stock ecu for driving when not boosting and vehicle functions.

I know I did not answer your question, but if you search in the archives, you will find numerous piggy back solutions using different fmu setups, fuel controllers and ignition devices.

Where we lack in our ecu is the ability to run large 440-500cc injectors with a 1:1 rising rate regulator. Factory turbo cars already have this built into their ecu and we do not. My guess is HRC has built a device that does this for us along with the unit controlling our crazy spark advance at part throttle. When under boost and part thorttle, our spark advance is waaaaaaaaay to high. We just want what the turbo guys have had for years. But we do not want a mas air sensor(if that is possible). I do have a feeling the device is going to use something to calculate the amount of air so it can match the right amount of fuel automatically. We are now adding the air and are guessing on how much fuel to add in the correct places to get the proper AFR. This is tough.

Sorry I did not answer your question. I am rebuilding my motor now and will most likely use what MR. Hahn is going to market. If the price is reasonable, then I will be headed in his direction. If it is too high for what it does for me, then I am going with an Electromotive Tec 2(used).

Cannot wait to hear how this develops.