VE and Inj PW effect on timing tables?

[LDMoore87]

Recently had to change the cam in my truck (11 5.7) and installed a BTR truck norris cam. Ive done a lot of reading on here and have the truck to where its drivable but its kind of a turd. Anyways i changed some things in my VE tables and Inj pw and fuel mass tables and it causes erratic timing at idle. It does it in both P and D. so i flashed my previous tune and it idles good. Verified the only changes were to the fueling and it does the same thing. Is there an adder or some table somewhere that would cause this? I did notice to that the off idle throttle response was a lot better but the idle quality suffered.Btr rev3 ve and inj pw.hpl btr cam rev 3 ve and inpw.hpt

[james1595]

Do not touch your injector data unless you've changed injectors. Fueling is done by your ve table. There are quite a few tables for spark and cam timing that can be adjusted to help it perform better

[Stoopalini]

Just for clarification, VE = Volumetric Efficiency, which is part of the air flow model. The number entered into a particular VE table's cell informs the PCM the efficiency of the air filling the cylinder. 100% means the cylinder is being filled with a volume of air equal to the maximum theoretical efficiency of the motor. Your VE tables exceed 100 in some cells, not sure why that is if you're not boosted?

That said, fueling is affected by VE since the PCM is going to try and keep the Fuel Air Ratio in check ... So increasing a VE cell number to be higher, is telling the PCM the cylinder fill is closer to the theoretical maximum (ie: closer to 100%), and will cause it to use more fuel to keep the ratio the same .... but VE is airflow not fueling.

Swapping a cam definitely impacts the air flow model, as you're changing the way the air enters the cylinder .... so adjustments to the VE tables are warranted after a cam swap if the neural network has been disabled (which it is in your tune). If Neural Network was still enabled, then you'd want to train the ANN for the change in the airflow model.

Like James said though, if you didn't change injectors, then don't mess with the injector data; as that data is meant to provide the PCM with the performance characteristics of the specific injectors. Some people will change this data to adjust for specific things ... but it's really only compensating for an issue somewhere else in the tune if the initial characteristic data is accurate for the performance of the particular injectors being used.

Who updated the VVT cam tables to account for the new cam specs? The values there do not look like stock 5.7 values, so I'm assuming someone either changed them with the cam swap, or prior to it.

[LilSick]

if you want help hmu

[LDMoore87]

All of the changes were made by me from reading through forums and watching different videos over the course of about 3 years and kind of just clobbered together TBH. Just about everything in that tune is from a comp cam I had in it before. It drove fine but wasn't ever very impressive. Probably less power than stock honestly. The main thing I'm really after is low end for towing but it should definitely be better on top also if I can get it right. My sons Sierra with a 5.3 has a good bit more low end 1500 to 3000 and tows better than my truck and his has much bigger tires on it. I may just start completely fresh on this tune since so many things have been changed over the past few years and this cam is completely different. VE tables need to be the first thing I adjust after the basic stuff to make it run? Then spark and cam timing and re-adjust VE accordingly? Should I disable some of the spark modifiers so its not using so many different tables? Have any of you ever noticed timing changes resulting from inj pw and VE table changes? Also would it be better or even feasible to try to tune it with NN enabled?

[LilSick]

I may just start completely fresh on this tune since so many things have been changed over the past few years and this cam is completely different.

VE tables need to be the first thing I adjust after the basic stuff to make it run?

Then spark and cam timing and re-adjust VE accordingly?

Should I disable some of the spark modifiers so its not using so many different tables?

Have any of you ever noticed timing changes resulting from inj pw and VE table changes?

Also would it be better or even feasible to try to tune it with NN enabled?

[james1595]

It's best to set your cam timing first, then adjust your fueling. Then when you are good, you can find tune your timing and fuel. What all is done to it. When I get home I'll check out your tune, if I remember, and give some tips

[james1595]

i looked at your tune and log, nothing screams that anything is wrong in the tune, but without a wideband, its hard to tell if the knock is from fuel or a mechanical issue. im leaning toward both, based on your log, you were adding 30% fuel at 1300rpm with 2 degrees of knock. i made a few changes to your tune to see if it helps. i added some fuel, removed some spark adjustment tables (temp based), and have a log file you could use to help log

btr cam rev 3 ve and inpw jw.hpt
engine tune.Channels.xml

[LDMoore87]

Uploaded the tune James adjusted and the idle quality has definitely improved. no more surging and jerking in Drive or P. I'm having another issue now but I know its not tune related. My bank 1 O2 bottomed out and had steady misfire on cyl 5. It only does this under 50-60% throttle and eventually the O2 will start oscillating again and the misfire goes away. Im gonna swap the #5 injector around and see if the problem follows the injector and change O2 sensors. The plugs are only a couple months old so i doubt they are the problem although they could be I guess. I did swap #2 and #5 coils this morning and made no difference. The truck has a BTR Truck norris cam Non MDS oem lifters, LT headers Efan and 4.56 gears. Ill attach the log with the misfires and report back when I get this issue fixed. As far as the KR goes I currently have the factory muffler on this truck so I can listen for any "Pinging". I had a tune previously that I for sure could hear Knock going on but it isnt the case with this tune. I know that isnt the most scientific way to do it lol but if you can hear it youve got problems or will have in short order. And ive also heard it on various other things Dirt bikes, fourwheelers etc. mainly under low rpm high load scenarios so I know the sound. Thanks for your time and adjustments. Its definitely more drivable than before. Btr rev4 w JW fuel and spark.hpl

[james1595]

Try getting gas, it's possible you just got some really bad stuff. Also I would invest in a wide band they would really help a tuner with your fueling

[Stoopalini]

See if your 2011 PCM has table ECM 2023. If it does, you can change it from "Global" to "Per-Cyl". Then add the 8 individual Knock Retard Cylinder channels to you scanner listing, and do a repoll next time you connect.

This will change the PCM to report knock activity per cylinder, based on the knock window for each cylinder, and it'll be available in scanner to track and chart out.

So when you get KR happening, you can equate it to a particular cylinder.

Agree with James, a wideband is necessary

In terms of the narrow band O2's, have you tried swapping them with each other? If the sensor itself has an issue, the "bottoming out" will move to the other bank. If it's an upstream fueling issue like you suspect, then it'll stay on that bank.

[LilSick]

you cannot log knock per cylinder with a new gen controller

cant even log it with a GPEC 2A

with 2A you can use engine position [2112] and do the math

that is all you are doing with your GPEC2A-18 anyways tom as the engine only has 2 knock sensors

[Stoopalini]

Of course you can on a GPEC2A-18, as I am doing it. Yes, there is only 2 knock sensors, but there is a knock window for each cylinder on each bank.

If you log the individual cylinder channels when ECM 2023 is set to Global, then all 8 channels in VCM Scanner will report the same activity. After you change ECM 2023 to Per-Cyl, each channel reports distinctly unique data based on the knock sensor activity for that bank and which cylinder window is open for knock to register when the noise occurs.

This is how I know cylinder #6 is my noisy cylinder. Prior to this, I only knew bank 2 was creating more noise than bank 1. I can hear what I think is a noisy lifter. So I enabled per-cyl, and sure enough, cylinder 6 has more noise than the other 7, and it correlates with bank 2 noise happening.

Ind_Cyl_KR.JPG

I wasn't sure if the other PCM's supported this, which is why I said "If your 2011 has ECM 2023 ...."

[LilSick]

Of course you can on a GPEC2A-18, as I am doing it. Yes, there is only 2 knock sensors, but there is a knock window for each cylinder on each bank.

my point was yer only looking at the crank position sensor and the 2 knock sensors

and iirc ECM [2112] will not populate when scanning a 2011 LX or LC with a NGC

[Stoopalini]

my point was yer only looking at the crank position sensor and the 2 knock sensors

and iirc ECM [2112] will not populate when scanning a 2011 LX or LC with a NGC

Gotcha, so I think what you're saying is the calculation the GPEC2A-18 is doing internally through ECM 2023, you can essentially do manually with other PCM's by time aligning the data from ECM 2112 with the knock sensor and KR activity data, so long as ECM 2112 is a supported channel?

[HaasExp]

my point was yer only looking at the crank position sensor and the 2 knock sensors

Virtually all modern PCMs only utilize only 1 or 2 knock sensors and then use a crank angle windowing function through their DSPs to monitor individual cylinder knock.

All the GPEC2A's I've come across have a per-cyl knock control option and you can monitor individual cylinder knock PIDs in the scanner.

I honestly don't know how you would go with using the engine position [2112] and doing the math because that channel logs far too slow to extract say a 40* crank window of knock data.

[LilSick]

right? you cant really. its only accurate once every 10 ms right?

even at only 3000 rpm the crank is already spinning 50 revs per second

ea cyl is firing 25 times per second (every 40ms)

being this is v8 at 3000 rpm there is a cyl firing every 5ms

wouldn't leaving [2023] on global provide additional protection

[Stoopalini]

wouldn't leaving [2023] on global provide additional protection

No, that’s not how it works. The PCM is tracking each cylinder independently already, hence the knock threshold tables per cylinder, by RPM by air charge.

These threshold tables are not simple thresholds though. They are a sensitivity control inout for the PCM. Hence why you can get KR even with RPM and air charge below the values, and can also not get KR when the values are exceeded. The PCM must be using a pattern recognition algorithm where these “threshold” tables are an inout to the sensitivity.

Setting ECM 2023 to Per-Cyl just enables the PID reporting to be per cylinder instead of global. I doubt it is changing the way the pcm handles the data for KR being triggered.

[LilSick]

which chrysler engineer told you all that?

[Stoopalini]

which chrysler engineer told you all that?

I think his name was Harry Bolz ? smart guy!