I've done many GM cars, but never stepped outside of that. Have a friend that has a scat pack challenger with a cam and procharger that he would like me to tune. I'd like to be able to figure this thing out as well... I've opened other files that I've found around the internet including hellcat files off the repository as well as a procharger base tune. I just can't get this thing to start consistently and idle.
Last night I went over there with a tune I compiled and unhooked the battery after flashing it for 20 minutes or so. I thought I was off to a good start because it fired right up! Looked a little rich so I went back to the VE table and pulled some numbers out to lean it out. Try starting again and it kinda fires, but never starts. Make a bunch of changes and keep trying, but nothing works. Go back to the original file that fired right up and it does the same thing as any of the rest of my tries last night. So I unhooked the battery again and go out to start it and it starts. Wasn't the easiest to get started, but it started, ran, idled great for 15-20 seconds before it shut off. Started it right back up and it idled for 15-20 seconds again. When it starts it revs great like there's nothing wrong, but to get it to that point is like pulling teeth and it won't stay running. There must be something simple I'm missing here, but I have no idea what I'm doing with the dodge ecu. lol
No start means needs more startup fuel and maybe more air. I usually force it into open loop until I can get a good read on how rich or lean it is and stop the fuel trims from having a heart attack.
It has ID1000's in it. I input the data (I believe it is all correct). In the file I tried yesterday with a bunch of changes I found a post of yours that was a reply to a thread with a guy asking similar questions so I tried some more startup airflow (I think it was 10%) and the other things your post mentioned. The car started with a little hesitation, but ran great. Surge at idle was minimum. Fuel trims were in the -25 to -35 area so I knew it was rich. I shut it off and pulled 25% out of the entire VE table. After that it never wanted to start again. It would kind of fire, but wouldn't take off and run. I tried going back to the tune that started right up and it still wouldn't start. Just seems inconsistent I guess. I know it has something to do with my settings, but I'm at a loss of what it could be.
To start I'd set your idle at 950. That's a decent sized cam with low compression so idle it high and then back it down once you get things dialed in better. You will probably need a lot more airflow under engine>airflow>electronic throttle>throttle body model>airflow. from .0 to .20 volts I would add at least 50% and you can smooth it out up to .75. .2 volts should have about 15-16 grams a sec.
Looking at a tune I have with for a car with same injectors, blower, and similar cam size the VE numbers are much smaller in the low load region. I didn't verify your injector scaling so that needs to be correct obviously. Also you may have to reduce the whole startup inj pw table by about 50%. Just giving you some rough ideas to help you get it started and stay running long enough to get data. Hope this helps a little VE B1.png
Thanks for the tips. I'll give them a shot! Is there any downside to using NN method of tuning vs speed density? I see some people suggesting PW scaling and others suggesting to use VE tables.
Well... ID has two different spreadsheets of injector data for Dodge so I guess when you use one instead of the other it doesn't work? Or more likely I just input the data wrong, but now it runs excellent. Fired right up when cold, needed some throttle warmed up. I added some more startup airflow to it and that helped a bit, but not perfect yet. On to the next learning curve I guess. lol
Last edited by Slow94Formula; 08-17-2018 at 06:43 PM.
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