I was reading actual dead-tree format books on installing and calibrating a stand-alone EFI system. Now I’m bummed out. It is starting to look like my best bet is getting a scan tool and figuring out how to bypass the error codes that will pop up when the factory controller finds out it is no longer sitting in a 1996 Chrysler Town and Country minivan but something a lot less in terms of mass and systems. There is already one minor system down that’s causing the Check Engine light to come on, what is going to happen when almost everything in the car is disconnected? I mean seriously my car will have no climate control, no doors or windows to check to see if they are closed and locked, no alarms on the seatbelts, and pretty much no anything else that doesn’t directly contribute to making the car go or stop, and on the stop side none of the hardware used in controlling the antilock brakes either. I might have to use the factory dash to get working instruments on this thing (but I still want to use the fake AM radio for starting the engine).
Now why would I be all bent out of shape on this after reading some books? Because the books pointed out I’m going to be going into this with no baseline fuel or spark maps to load into my standalone engine controller and no information about the injector flow. They do say how to create those maps the way the OEMs do, there is just one stumbling block: I would need to rent a chassis dyno for as long as it would take to create those maps, which could easily cost as much as the rest of the car, one place advertises $179/hr, another $100/hr, and a third place advertises $150/hr. The place with the $179 rate has a flat rate $700 tune for a speed-density system (like the Megasquirt) and I don’t know if any of them could program a flex-fuel map that would let me refuel with 93 octane if E85 wasn’t available.
There are piggyback controllers that would let me remap the fuel and spark for E85 and also leave the original maps in place for fallback when E85 was not available. But I would still need to use a dyno to tune it accurately. I could just multiply by the difference in Stoichiometric ratios to get a ballpark figure for E85 and get pretty good performance, but that would still be leaving horsepower and fuel economy in the engine.
Well, it is late and I may have things to do in the morning. so bye! Opus the Unkillable