NoCar340:
Sorry, but the experience I have just had with a FAST EZ-EFI doesn't jive with what you wrote. In this case, it was a Chevy crate 350. System got installed (not my car), and it started out really rough. Smoothed out some after about 10 minutes. It was driveable, but running rich. Owner continued to drive it, and it has gotten better and better. It does self learn. I would not even suggest that it is anywhere near a factory port fuel injection system, but mileage and driveability have improved greatly vs. previous, "expertly tuned" Edelbrock 1406 carb setup. It is showing improvements still, 3 weeks after the installation and initial fire up, but they are smaller and smaller.
The FAST EZ-EFI doesn't have a 2 GHz/8GB of RAM, that is for sure. But guess what, neither do the factory units. Reason for that is that they don't need it Most of them are microcontrollers (like what is built into your laser printer) and most have 32MB of RAM or less. Now, the argument will be made that the factory computers don't need a lot of RAM because they are optimized for their specific application, and there is some truth to that. But the flip side of that is that the "fuel injection computers" in today's cars not only run the fuel injection, but the ignition, and in the case of my Dodge Grand Caravan, the transmission and a few other things. . In today's world, with the types of CPU power that is available, it is certainly possible for any competent after market parts manufacturer to come up with a processor/RAM combination that easily exceeds the capabilities of what the factory has put out. Putting in a higher end microcontroller (ie faster and more capable, and remember, these fuel injection computers only handle fuel injection) and 256 MB of RAM (an almost trivial amount, these days) will allow a lot of flexibility. It is not only possible, but highly probable that the third party fuel injection computers are much more capable than the factory fuel injection computers, because they have to accommodate being installed into so many different situations, so are required to be more flexible.
As to the limited parameters the third party fuel injection computers have to deal with, that is somewhat of a non-issue. The EZ-EFI system that I helped with has an O2 sensor, a coolant temperature sensor, a MAP sensor, an Air Temperature sensor, throttle position sensor, and an RPM input. For a system that only controls fuel, you don't need anything else. There is certainly no need for cam position sensors or crank position sensors, as they don't control the ignition, or road speed sensors, or gear position sensors, or anything like that.
The process starts with you entering engine size and number of cylinders, idle RPM, and then you leaving the throttle alone, but with the engine on, but not started, and hit a button. This is the position of the throttle at idle. It then asks you to fully depress the gas pedal, and push a button. This established full throttle position. Engine operating temperature is set when you start the engine up, and it asks you to wait until the engine has reached operating temperature and hit a button, I would guess that it reads the coolant temperature sensor for a value. It then asks you wait for a while until it is finishes. It starts cycling back and forth for a while, and then settles down. From there, you have a basic tune. It self adjusts from that point onward. At any point, you can go in and change a lot of parameters, from A/F ratio to idle speed, to a whole whack of other things, like throttle curves and quite a few others. Things like cylinder filling and accommodation of timing parameters is picked up by the O2 sensor, I would think
There is no doubt that a finely tuned carb can come close, or equal these type of fuel injection systems for power. There is also no doubt in my mind that carb parts are getting harder to find every day, and that no matter how well a carb is tuned, the driveability of these third party fuel injection systems will still be better, and so will mileage, most likely. In addition, the expertise in tuning carbs properly is dwindling rapidly. There is nobody locally that can tune the TQs in my 2 four barrel J bodies, and nobody that I can learn from. The local hot rod shops have no issue tuning up Holleys and Edelbrocks, but they won't touch my TQs, and I want to use my TQs. I will have to send them out to a carb rebuilder as I don't want to do them myself. I have tried to find metering rod kits for my carbs, for a few months, but nothing yet.
The other thing to keep in mind is that FAST does have full port injected systems that are far more capable of producing high horsepower numbers, much higher than anything the factories have come up with, so they knowledge, experience and background are there. Question is, how much do you want to pay to get that Nth degree of perfection? . This isn't the first kick at the can for them, nor are they an new unknown quantity. Most people don't have the knowledge or expertise to program a fuel injection system from the ground up, whether it be a modified factory system or a third party system, so they just modify the fuel maps.
Kostas