4 Attachment(s)
Guidance on injector tuning for 2015 Hellcat.
Total noob here but trying to learn. I want to add larger injectors for future plans: pulley and boost a pump. I am ordering ID-1050-XDS (1050.48.14.14.8) and plan to install them myself (easy day) and do fueling for P/T on the street and then WOT testing on a dyno (the hard part). To begin tackling this task I pulled down the injector data from their website (http://help.injectordynamics.com/hel...nts/4042718026). After looking at the data I went and loaded a read of the current tune in the PCM and adjusted the following tables:
[ECM] 34050 - Injector Pulse Width vs. Fuel Mass
[ECM] 34052 - Fuel Mass vs. Injector Pulse Width
[ECM] 44436 - Startup Injector Pulse Wdith Scalar
[ECM] 44439 - Inj PW Min
[ECM] 34070 - Injector Pulsewidth Offset
[ECM] 34086 - Fuel Mass Mult vs. Fuel Temp
I noticed that while inserting the data into the UI I could not get exact values to be placed into cells. I placed a ticket in with support as I thought this was a bug and they explained that there are only certain values that can be placed in fields that the original programmer of the PCM/TUNE will allow. I thought this peculiar because what is the difference between 2000.00 and 2004.00. Apparently Binary Coded Decimals on smaller memory footprint systems is a thing, but I'm challenging this assumption so lets see where that goes. I digress. So I tried my best to make sure that the values lined up closely but I learned there is a lot of interpolation that happens on the backend in VCM editor on its own. Don't know if I am a fan of this but I guess I can get used to it as long as I get the results I want and nothing turns into a grenade.
I've attached a screen shot of what I am talking about
Attachment 104100
How I scaled the Inj. Pw. vs. Fuel Mass and the inverse table is another story. I noticed that in the stock tune the line is linear so I thougth that if I could get my new data to match that line via linear interpolation I'd be in a good spot to start off with till the pulley comes in. In the same spreadsheet from ID I made a new table and added a linear intepolation function using (0,0) and (443.741, 30000) as the known lines on a 2D graph. From there applied standard linear interpolation and came up with the following values:
Attachment 104101
I did a comparison of the graphs and they both look very linear and the slope is almost the same.
Attachment 104102
Attached is the tune as well.
Attachment 104103
So I have the following questions:
1.) Am I doing this right or is there another method that I'm not aware of?
2.) Did I miss anything that anyone would like to share?
The math makes sense in my head because the ID 1050 injectors are on a ratio of 10:21 bigger than stock so I'm okay with the values I created. What I can't get over is that I can't type in exact values into the UI. Is anyone else experiencing this? Is this by design or have I once again found a fringe test case.
