I have been spending the last few months learning and reading and learning and reading and now trial and error on tuning my own 426ci Whipple 2.9 2006 Chrysler 300C SRT8 with a NGC3 CAN PCM. I want to share the basics I learned and picked up along the way. This is a thread I want folks to post to with their own procedures and questions, but if it is a very SPECIFIC question to a unique situation, appreciate if you can start a new thread and leave this clean.
First of all, HP tuners has already posted up a description and walk through of the GM E78 PCM, which is the near identical logic the NGC PCMs use, which is torque based closed loop. Basically, the computer tries to calculate what torque your right foot wants, and then calculates what the engine is putting out based on its current state, and makes adjustments via timing and throttle body adjustments. Its a royal PITA, but take the time to read this link, then read it again.
https://www.hptuners.com/help/vcm_ed...vanced_e78.htm
I will go in order of the tabs in HPTuners for how to build a baseline tune. These procedures were how I got my aggressively cammed and overspun Whipple to idle and drive nicely. If you have a mild cam and aren't spinning the crap out of your blower, you can dial back my adjustments I recommend or make them the same knowing you may have to dial them back in later tunes. USE AT YOUR OWN RISK, these are my own guesses and experience on getting things right, suggest better ways and I will update these...
General
Set your Engine Type - this is your factory engine size
Set your Engine Size and Displacement - make these both whatever your CURRENT motor is, if factory make the same as Engine Type
Idle>General
Stopped VSS - this is the vehicle speed under which idle condition is declared. I raised this to 5mph, as I noticed in parking lot crawls the car would lurch all over the place as it would switch from idle to run mode, you can leave stock to start but if you experience the low crawl lurching right around 2-3mph, I would raise this
Idle>RPM
Base Idle RPM - set these 4 tables identical to start, for a big cam car have the bottom two cells be 850rpms, from top to bottom 1100, 1000, 950, 850,850. If you don't have a huge cam, you can start at 800 in the bottom two cells.
Minimum Reverse - set to 25rpms ABOVE your bottom two cells above, mine is 875. Reverse has a higher load and often needs a bump.
Idle RPM Limits
Set all your minimum tables so that your top row is your current bottom two cells of the Base Idle RPM tables, then next one down 50rpms. So mine is 850, 800, 750, 750, 750. straight across. You want your bottom 3 rows to be about 100rpms behind your Base Idle RPM bottom two cells, adjust accordingly.
Set Max Drive to 1800, Max P/N to be 1,500. These you can adjust, they should be slightly higher than your Base RPM Limits + adders (see below)
Idle Runtime Based
P/N Adder - I added 175rpms to the first three columns and from 67.4* and hotter cells. This will make your car idle a little higher each time you restart and then fade back to your base idle. Rest of these adders I left stock.
Idle Misc
Power Steering Adder - I put 25rpms in this table. I run a 17% OD lower crank pulley which spins the crap out of my power steering pulley, which puts an undo load on the motor and makes it idle down whenever I turn the wheel. This table will add whatever rpms your put here whenever it senses load on the power steering system.
Idle>Airflow
This takes the most time, but in this tab open each and every proportional, derivative, integral drive table (both torque spark and torque throttle) multiply the entire table x 50% or 0.50 as a starting point. Set every single max and min to match your NEW calculated max in min from each table (the top and bottom cells). Pay close attention to the positive and negatives in each max and min and keep them consistent, they don't always make logical sense. This includes cutting in half the Idle Torque Spark Deriv and Max lb/ft fields. Set your Enable RPM Error RPM to 500rpms, this desensitizes when the idle spark corrections can kick in, you're telling the pcm if the rpms are 200 above the base idle, don't do anything, if its 600 rpm above, go ahead and use timing to adjust it.