My Megasquirt adventures over the years

So now that my car has become my primary daily driver, I've been spending a lot more time working on the tune and digging into the little details of things to try to get it running as nicely as I can. For a little history and backstory, my car started life with me as a carbed 318 with a 4 speed. That eventually changed to a carbed 2006 5.7 Hemi with the 4 speed, then I converted it back to fuel injection and put in a 6 speed. I bought my engine with no electronics, so that was one reason I went carb at the start. My Megasquirt adventure began when the guy I sold the stock 5.7 intake to told me he knew a guy taking a system off a 340 if I was interested. I was, and it seemed like too good of a deal to pass up, even if I wasn't going to put it on my car right away. The guy was basically selling a "fuel inject a small block Mopar in a box" kit. I got everything from an intake manifold, throttle body, fuel rails, injectors, fuel pump, wideband O2 sensor and controller, computer, power distribution panel, wiring, etc. I sold off everything I didn't need for the Hemi an ended up with a nice Megasquirt 2 v3.57 system and components for about $200.

Some quick background on the engine as well:
2006 5.7 Hemi
Truck timing cover
Indy ModMan intake
TTI headers
Inertia Motorsports SRT Max Plus cam (with 6.1 exhaust springs on all the valves)
Otherwise stock bottom end and heads, just freshened up with new gaskets/seals/rings/etc.

So this is where the saga begins. I had already bought an Indy ModMan intake for my carb swap (limited other carb options at the time), which I knew could be set up for injectors. I had the MSD Hemi 6 running my ignition for the setup as well. I inquired with Indy about drilling the manifold, but it was going to be more expensive than I wanted. I found an injector drill bit and had a friend at work with a mill, so I bought some blank fuel rail lengths and took them both over to his place and we drilled everything out so I could get the injectors installed. My MS was set up to run a distributor and coil style ignition system (only one spark output basically), so it wasn't going to run the Hemi coils without upgrading. I opted to run the MS as a fuel only setup and leave the MSD box to control the spark. I set up the system as batch fire with two banks of injectors, so 4 injectors would fire at a time. It was fairly simple to set up the MS to run fuel only as I didn't have to worry about any cam or crank triggers or anything like that. I just took the tach output from the MSD box and fed that to the MS to run things. I couldn't tell you where my initial tune came from. I think it might have been the VE table generator in the program (using published hp/tq numbers and rpms), or maybe it was the base 350 Chevy map, who knows. It was 10+ years ago and I know at one point I started that whole tune over from scratch. This initial setup was fairly basic. I wasn't using many of the features/capabilities of the MS, largely because a lot of them control spark to do things (like traction control), and I didn't have that. I had my idle control set up open loop to just modulate my IAC with coolant temp. It ran fine, though I never would stop tinkering with it. Every time I'd get it to the point that it was running pretty good (I thought), I'd tell myself I just needed to leave it alone and enjoy it for a while, but then I'd start looking at things and figuring out the next thing to mess with. The first big overhaul to the system was rewiring everything. The power distribution module that I got with everything liked to melt the fuel pump fuse housing, though never blew the fuse. It was a screw terminal setup and just kind of hokey, so I moved a lot of that stuff into a little enclosure in the engine bay and wired sensors directly into the main MS plug. I drove the car on and off over the years with this setup, but ultimately speaking it really didn't get all that much road time. I would take it to work here and there, but without A/C it was definitely a "fair weather" kind of car. The cover probably only came off once or twice a month if that and it kind of just languished in the driveway.

I did some pretty dumb stuff with the tune on the setup over the years. Probably one of the first "head slap" moments I had was when I set up my original AFR targets to gradually richen the mixture going from cruise to power. I thought it made sense at the time because it made for a nice smooth looking table that went from ~15:1 at light load cruising and gradually worked its way up to 12.5:1 or so on the top end, but that also meant that I could be cruising at 14:1 or something depending on where I was in the table. That's not really how modern engines work, as they generally operate at 14.7:1 almost everywhere but the top end, so I retuned it so the majority of the table was 14.7 and only the top end of load and rpm dropped that for power.