NGC3 CAN Low speed cruise issues.

[briglicon]

I have a weird issue when cruising at low speeds (30 to 40 mph) and light throttle. I get this slight cyclical surge that I feel in the car and hear in the exhaust. I've been working on my idle tuning using 06300SRT8's write up with OK results, and my VE tables are in decent shape. I have a feeling that there is some table or torque setting that I'm overlooking or not finding the info on how to adjust it that may be the cause. I also have a sneaking suspicion that the little bit of occasional idle surge I have left may be related. I have noticed that while cruising in this problem area that my timing will jump up a couple degrees each time i get the surge. If I crowd the throttle just a little bit or get more of a load on the engine it will smooth out... but as soon as I am just maintaining low speed it starts again. My passengers look like they are softly jamming out to a slow song in their heads. Not good. Otherwise, the car makes power and runs good. My setup: 2005 Chrysler 300C, 5.7L bored .75mm over with KB piston, Comp HRT stage 1 cam (216/222, .500/.495 lift, 113 LSA), long tube headers, Flowmaster 3" cat back system, no cats. Base PT and WOT timing is stock with 2 degrees added, 1 more in the hwy cruising area, but they still need a little work. I've attached my current file and a log I took on my drive home from work. Any help or ideas would be greatly appreciated. BTW, I tune lots of LS, this is my first Mopar.idleTrial07.hplCamIdleTune09.hpt

[AVMPerformance]

Your fuel trims look way off to me, if you watch them, they jump around too much and rather large amounts. Personally, I would work on smoothing out fueling within 5% on each bank then see if your issue gets fixed or better. I also noticed on your tune you don't have a parameter for 02 sensor delay. From what I have learned and had other tuners adjust in the past, the 02-sensor delay helps smooth out the fueling since you moved the 02 sensors further from their original location. When I added to the delay it helped smooth out my surge issues at low speeds, this may help you. Another professional tuner may jump in and correct me on this is im wrong, but I fairly certain you want the fuel trims to be as smooth and straight as possible.

[briglicon]

I saw a little info on that. I will see if I can find out how to do it. It's at least a place to look. Thanks for the tip!

[rays04gtx]

Couple things,
1) Start logging Throttle Voltage ,
2) most of your issue is in Engine>Torque Model>Loss>table 12882.

See post https://forum.hptuners.com/showthrea...l=1#post691784

there's few other tricks to make it go away , but 1st start at table 12882.

[briglicon]

Ah. I read that thread but missed the part about adjusting friction loss for the area I'm having trouble in while driving. I have been tinkering with that for the idle. Still not perfect, but getting close. I have problems when I crank the car after it sits. It'll die while I'm backing out of my spot. Once it's been running a bit, I have almost no issues. Maybe an ect adder... hey thanks for the advice!

[briglicon]

Yeah, no way to adjust o2 delay on this pcm that I can find.

[PurpleRam]

Yeah, no way to adjust o2 delay on this pcm that I can find.

There is but it’s not the same as Gpec