Mopar Stage 2 + 6.4L Injectors: Help

[moparmajba]

I recently built a 5.7L Hemi with a Mopar Stage 2 camshaft and 6.4L injectors. The car is a "2009" running the NGC4. The Stage 2 sits between a Comp 266 and 274 and does have a limiter installed. I built this engine to confirm to rules for a racing class, hence why some of the decisions were made. I found out after the fact that 6.4L injectors may (keyword "may") have been overkill, but I still think I should be able to make them work.

I've gotten the car to start fine and have heat cycled it a few times, but the engine really starts to struggle after a few minutes. I currently have idle set at 800, which it will sit at happily for that time, but then it will start to dip and struggle. It doesn't seem to be ECT related as I have restarted it after it dies and it will run again for a few minutes happy and then do the same thing.

1) Could the idle issue be caused by flashing the vehicle? i.e. When I flash it, it seems fine for a while, then struggles, almost like some adaptives kicked in and made it unhappy?
2) Are there any additional pointers for helping idle? I've changed RPM and timing and the torque model (to save lift-off instability). I had been running with the Evap circuit removed and forgot to plug the tiny hole on the manifold...could this have caused the issue (seems unlikely to me)?
3) Does anyone have the Inj PWM HP tuner info for the 6.4L injectors? I tried adjusting by a percentage as a starting point, but it starts super rich and the fuel trims are still high (20+%)

Any ideas what could be happening or additional info to help a stable idle, let me know. Based on how it works, I don't think it's mechanical at this point, just in the tune somewhere.

Thanks.

[white1]

1. Yes as adaptives are built it can change how it starts/idles/runs
2. there are several things in addition to idle rpm that need to be adjusted in order to have a good reliable idle/start up
3. I know there are some differences between the NGC4 and GPEC2/2A injector scaling.

Here is a stock file for a 6.4 car you should be able to copy/paste some of the injector parameters to get going
This tune worked with a 274 cam, so you can use it as reference, but will likely need to make some fueling adjustments for the slightly smaller cam. Should get you started though

2012 charger 6.4 comp 274.hpt

[moparmajba]

Thanks, I'll give this a shot this evening.

[james1595]

So ive got a question, ive got a 5.7 with 6.4 injectors. I didnt know how to scale them, so i did all my tuning through the ve tables and it runs pretty good(+/-5%) for my fueling. So is it needed to scale the injectors, because i didnt

[f.creek-ranch]

set injector data from 6.4 .
Search for injector scaling in the forum.
Now log the stft and ltft and correct the values.
Thats it.

[white1]

set injector data from 6.4 .
Search for injector scaling in the forum.
Now log the stft and ltft and correct the values.
Thats it.

That tune I posted has the stock 6.4 injector data in it