Sean, what you are trying to do won't work. The problem is the injectors. First of all, you must understand that the 160# Ford Racing injectors are low impedence. This means they are peak and hold. While the factory high impedence injectors get a nice even 12v from the ECU, they initially flow more than the rated amount of fuel. Then, pretty quickly (at the breakpoint), they return to the normal rated fuel flow. Imagine a garden hose that you've got your thumb over. You release your thumb, and the water shoots 10 feet, then pretty quickly settles back down to only shooting 5 feet once that initial pressure bled off. This is how factory injectors work. You already probably found the factory Ford specs for the injector...
http://www.fordracingparts.com/parts/ics/m-9593-e303.pdf
Normally, the high slope is # of fuel per second. So if you multiply this times 3600 (60 seconds x 60 minutes = 1 hour), you would get the fuel injector size in lbs/hr. Take a 19# injector for example. With a high slope of .005445, times 3600, you get 19.6 #/hr. That makes sense.
Now Ford still rates their 160# injector the same ways and all. But how they are actually applied in a car is different, because it's a low impedence injector. Ford basically nails the injector up front with a bunch of voltage, to open the injector up quickly, then immediately backs off the voltage bigtime, keeping just enough voltage to hold the injector open at the desired flow rate. Thus the peak and hold terminology. Now watch what happens when you try to use this injector as if it were a high impedence injector: Take the hi slope of .035086 and multiply it times 3600 = 126.3#/hr. Sounds lower right? But remember there's not nearly as much lag time, so that injector would start flowing faster. In the end, it's going to flow 160#/hr at 39.15 psi like Ford said. But how it got there is a different story.
Your REAL big concern here is injector drivers. If you run the stock ECU with these injectors, you WILL burn up the ECU's injector drivers, because they are not designed for the extra power that peak and hold injectors require. You need to look into an aftermarket injector driver box.
Next, you need to understand what Don was talking about with lambda and stoich values. Think of Lambda as the percentage of oxygen that's being used. For example, .8 lambda on gasoline (a 14.7 stoich) would = 11.76 air/fuel ratio. But a .8 lambda running E85 (a 9.85 stoich) would = 7.88 air/fuel ratio. Tune in lambda and don't worry about air/fuel ratios! The O2 sensor sees lambda, and then multiplies that lambda number times the preprogrammed stoich value to come up with an air/fuel number anyway. You should shoot for around a .8 lambda on a turbo car (maybe .78 at the richest), and about a .85 lambda on a n/a car. Regardless of fuel. Shoot for 1.00 lambda at idle, unless you have a lumpy cam. Then you might need to throw some extra fuel at it, like .96 lambda or something like that.
You can change the stoich value in most Ford PCMs from the 14.64 gas setting to whatever you want. In the case of E85, 9.85. The fuel tables are already listed in lambda, so that alone will effectively retune your car for a different fuel, assuming you want to keep all the same lambda settings in the base fuel tables. You would still need to retune spark tables. Since E85 is higher octane, you could and should move the borderline spark tables closer to the MBT tables, to take advantage of the higher octane gas. Some dyno testing would be advised here, to know exactly how far.
When you try to scale stuff, it should probably only be for one reason: you hit the maximum lbs/hour of air that ECU can allow. Otherwise, scaling is a bad idea. Certain things are scaled together also, but not all things. Like the lo and hi injector slopes, cubic inches (to keep load right), and maf xfer function. But not the other injector values! The flow is changing here, but not the time the injectors take to open or close, or the battery voltage effects on the injector.
Adding a MAFia to the airflow meter will just cut down on the size of the voltage coming out of the meter, making the ECU see less air. It may be a way of working around a pegged MAF by scaling it, but it also would lower load. Lower load = higher spark table values. Higher load = lower spark values. So as you increase airflow (increasing load), you would be increasing spark values because the ECU sees the lower mafia values, and assumes that lower airflow and load. On a turbo car, this is not a real good idea! Same thing goes for calibrated airflow meters. Fox bodies don't use load for the spark tables, so a calibrated airflow meter can work out "ok" on them, but SN95 5.0 cars and all mod motor cars do!
Unless you exceed the ECU's airflow limit of 63.9#/minute, leave calibrating, scaling, and mafia'ing out of the picture. Also realize that each injector has a minimum "on" time, as stated in their specs. If you have a 160# injector, at it's minimum on time is 1.642 ms, then that's the minimum squirt of fuel you can get at idle. If that's more than your motor requires or can handle, then it's gonna get rich quick. This is the problem with big injectors, especially on small cubic inch motors. They may be able to handle that fuel up high with a turbo setup or something, but at idle they might not want as much fuel as that injector forces upon them.
If you decrease the slopes of the injectors, you're telling the computer that the injector it's controlling is smaller than it really is. That will make the computer possibly command a higher pulsewidth value to get the same amount of fuel. So don't scale that unless you're scaling maf xfer and cubic inches as well.
In short, you need to model the fuel injector very accurately. Then you can model airflow correctly using the wideband. If the ECU knows the right amount of air, it will calculate the fuel right for you... assuming you told it the right injector values.
You might also want to read this article on injector specs...
http://calibratedsuccess.com/Assets/Documentation/Fuel Injector Article.pdf
It may help you understand injector modeling better. If you learned nothing else, learn this: Your stock ECU will burn up running 160# low impedence injectors. You need an injector driver box for sure. If you can do the math on how big your injectors need to be for your power level, and find that you can get away with 80# injectors on E85, then switch down to them. It will make everything a lot easier for you. Also, Don is right about stoich values changing depending on how much alcohol the fuel has in it. Bear that in mind, and consider running the worst lean stoich scenario, and that goes for timing values too.
