I've just realized there's a sample 300C file to take a look at. I've been trying to get my head around the basics of Load, Fueling and Spark on the NGC system but it seems like a whole different ball game compared to Ford and GM. If anyones got some pointers or tips, please let us know so once the software FINALLY gets released, so we have some background information.
What I've written is completely my own theory about tuning Dodges and could be completely wrong. Can't get to bed so wanted something to tire me out.
Load:
The load I've seen the NGCs use is Pressure Ratio. From what I understand this would be (Barometric Pressure + Manifold Pressure) / Barometric Pressure = Pressure Ratio.
An example of a good breathing engine at sea level would be:
14.6psi + 98kPa [14.2psi - 14.6psi = -0.4psi] / 14.6psi = 0.973 Pressure Ratio
Please note to get Psi from Map (kPa) is 1 psi = 6.8948 KPa, or use the HPTuners unit conversion tool. Boost PSI is measure anything over Barometric PSI just to clear things up.
I only hope HPTuners will support the Barometric Pressure PID in order for us to tune these PCMs properly and get our calculations spot on. Good thing at my side of the world is we're pretty much at sea level all over the country so Barometric Pressure should be a good 14.2-14.6psi and tuning should be straight forward.
Fueling:
I didn't manage to find a simple OL EQ Ratio/Lambda table for us to command fueling with, so I've created my own theory. (THIS IS COMPLETELY MY OWN THEORY AND IT COULD BE WRONG AS HELL, I'M WRITING TO BE CORRECTED AND LEARN THE NGC OS SYSTEM)
You've got FA Stoich:
The only way I could understand this was to logically try turning the values into something readable like GMs EQ ratio. This is what I came up with:
If I try change FA stoich into an EQ ratio of 1, the formula I did was:
FA Stoich: 14.7 * 0.0694 = 1.02 EQ
EQ Ratio: 14.7/1.02 = 14.41 AFR (Stoich is 14.7 but there could be another adder that sets the FA Stoich to EQ 1 actual that I haven't found yet.)
Now the FA Power Enrich has a table set up with Pressure Ratio vs RPM.
FA Stoich + FA Power Enrich: 14.4 * [0.0694(FA Stoich) + 0.0186(FA Power Enrichment)] = 1.293
EQ Ratio: 14.4/1.293 = 11.14 AFR
By getting those AFR values at the end of the equation, it does seem like the results are believable and this method could work. I guess the only way would be to actually tune the car and change the FA Power Enrich to give me a 12.5 AFR.
To do this I would reverse the equation:
14.4 / 12.5 = 1.152
1.152 / 14.4 = 0.08
= 0.08 - 0.0694(FA Stoich) = 0.0106(FA Power Enrich)
So in my "theory" in order to get a AFR of 12.5, I'd change the FA PE to 0.0106.
Once I get my commanded fueling out of the way, I'd work on the VE tables. They are set up as Load (PR vs RPM). Since I know how to work out what PR the engine at hand will be running at, and getting my commanded PE set, the VE tuning should be as straight forward as tuning a GM vehicle.
Spark:
Once you get your head around learning how to figure out the load of the NGC platform, tuning spark should be straight forward. The WOT spark tables show higher values then the MBT Spark tables, but once we get the software released on HPTuners, a dyno will come in very handy changing out the MBT of the vehicle and help us to dial in WOT Spark.
Please I again need to state, I have never tuned a Dodge vehicle with a custom operating system. I have tuned them using handhelds, and what I wrote above is what I could understand from the tune file itself. If its nonsense go ahead and let me know, I'll be more then glad to change anything written!