Probably something like THIS. Busy only starts to describe my life lately. The program I'm working on for my day job is seriously in "crunch time" for fuel economy and emissions certification. That doesn't leave me with a lot of time to police the forums.Originally Posted by Sam88gta1
More to the point here, the data provided in the DVD is the mathematical derivation of Ford and Continental's published injector characterizations. I only translated the existing data within the OEM constraints. The minimum pulsewidth is a great example here. Ford and Conti have pretty stringent standard for shot to shot variability, so the statistical variation at short pulses with these giant injectors drives an OEM requirement that one doesn't let it get down there too far. Obviously, this large minimum pulsewidth means a large minimum fuel mass which makes it difficult to get the desired mix at idle and light cruise on smaller engines. If you had an 8.0+ liter engine that swallowed huge amounts of air even at idle, a large minimum fuel mass wouldn't really be a big deal. On a 5.7l idling under 800rpm, it can be a different story altogether.
So what does this really mean? In short, you're going to need to be a little creative if you want to effectively use a very large injector on a relatively small engine. Most likely, the first thing you're going to violate is Ford/Conti's definition of "consistent" for minimum shot size. Sure, you'll get more variation than the typical emissions calibrator wants. But in the racing arena, chances are that you'll get by with a little more variation that is accompanied by big power up top.
Reducing rail pressure reduces the linear flow rate (IFR table), but also has an effect upon opening delay and nonlinearity (short pulse adjust). The trick is not to go too far with pressure changes. The data provided is based on a nominal 58psi (4 bar) and remember that GM defines the offset MUCH differently than Ford in units of time. Rather than just globally dropping the rail pressure, why not use a 1:1 regulator? It does everything we want; less pressure/flow at idle and more under boost. This goes a long way toward making the calibration process more simple and successful, regardless of the injector chosen. I do this on my personal twin turbo LS3 corvette with 60's.
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) and let them setup your base tune... unless you already know the shop that you're going to have tune your truck? If you know who you're going to, perhaps they can hook you up with a base tune given your mod list?