Pope thanks for the input and comments. You see very knowledgeable with this... did you pick all of this up from tuning your Stang?
VE tables are extremely difficult (I think) to construct. Having to create that table alone is enough to steer me away from attempting to switch to a MAP system.
somewhat.
I started learning by researching the various options for my Mustang as I constructed it. The DIY and Open-Source nature of the Megasquirt system coupled with the various code variants that make it capable of handling most of the features available in other standalone systems, but for half to quarter the cost. I am no expert and there is much that I have not yet committed to memory, but I like to think that I have the general concepts down.
Even if you do not use a Megasquirt system, the MegaManual (
http://www.megamanual.com/) is a wonderful resource for reading and developing an understanding of how ECM's function. Some of the material is obviously specific to the MS unit (primarily settings and tuning specifics), but the concepts in play can be generalized to probably all fuel injection systems.
Additional resources that I have found of value are tech books issued by various manufacturers for the instruction of their employees or for use in trade schools to train new techs/mechanics. These can be found in a number of ways: eBay, Amazon, trade schools that may have old versions to unload (check and the end of each school year), and from techs/mechanics that may have old editions lying around. I have read the Ford, GM, and one of the import's (Honda I think) instruction manuals from a couple years ago, for the most part these resources are light on the background of how and why the systems are implemented the way they are, and heavy on diagnostic procedures, but understanding how to diagnose failures and the effects that component failures have on the ECM will aid in understanding the system functions.
Automotive Computer Controlled Systems: Diagnostic tools and techniques by Allan W. M. Bonnick is another decent reference that approaches the ECM from a generic perspective explaining how various systems function, the physical manner in which sensors and controls operate and how to determine if there are problems in the components.
Understanding Automotive Electronics by William B. Ribbers, on the other hand, is a more technical reference book with more emphasis on the hows, whys, and mathematics behind the control functions.
Although slightly outdated, and having nothing directly to do with the ECM functions, I must recommend that anyone looking at Forced Induction (most specifically turbos) read Maximum Boost by Corky Bell. Despite being written for the purpose of understanding turbo systems, a centrifugal supercharger is effectively a turbo compressor being driven by a belt, so much of the compressor tech is applicable, the book also covers intercooling which is obviously applicable, intake design, fuel system alterations (FI and Carb), and how increased pressure impacts the engine, so it is all good information to take in.
I could go on and on, but I will stop here, as this should give an idea of the types of resources available. The information is widely available and not hard to find. I leave the topic of references with two parting thoughts: For what it is worth, one can find various levels of ECM tech on Wikipedia depending on the topic, which makes is a good entry level information source, and that the MegaSquirt community is a great resource for learning the how and why ECM's function as they do; as previously detailed the MegaManual (
http://www.megamanual.com/) is a great place to gain an idea of why computer controls work as they do, but if you really want to understand how controls function, buried in the discussions at the
http://www.msefi.com/ (the MS Forum) if one should care to look, one will find development information that goes so far as to discuss the algorithms used to drive system functions and what industry papers the functions are derived from (serious engineering material), additionally, if inclined, the C++ source code the for entire MegaSquirt system is freely available so that could be reviewed to understand how it functions.
In my opinion VE tables are not difficult, time consuming, but not difficult. However, I have to venture a guess that the factory ECM is not going to support speed density over mass air since the control algorithms would be wrong. If you did decide to move toward a stand-alone, the tuning softwares that accompany the units will usually generate base tables from the input of a variety of factors and estimations. Fine tuning is then performed to refine the tables to the engine, most easily performed on a dyno where operating conditions remain controllable and adjustable to suit the section of the table under refinement. I do not know off hand what stand-alone ECM's support MAF sensors and which ones MAP, but the Megasquirt can use either or both according to user defined settings.