Burst knock wont stop

[MrTurbo]

2010 Silverado 416CID, longtubes, muffler, and CAI - stock injectors, heads, cam etc.

I have not been able to get the burst knock under control, any abrupt tip in throttle and it goes nuts.

Tried increasing and decreasing the burst knock settings to no avail. It definitely seems to be real knock.

Feel like if I had a accel enrichment table it would be easy to solve with adding more fuel to tip in...

But im a novice so I expect there is a learning experience in this for me, lets see it

PS I was dialing in the tune for ethanol on this log, I have since reduced some of the timing and added a bit a fuel in the corresponding areas

6.0.hpl

6.0 VE Working Flex enable.hpt

[schpenxel]

It's going to be pretty tough to tell whether it's burst knock retard or not if you're not logging burst knock retard

The highest amount of actual true "knock retard" is that entire log is 2*. Not much.

The rest is coming from something else

Add burst knock retard to the list of channels you're logging. If it isn't showing up in that one then log everything you can find that adds or subtracts timing. Something will stick out.

[MrTurbo]

Thanks,

What i meant was not that i have a problem with burst knock retard, but what looks to be actual burst knock. The knock sensors are consistently triggered at throttle tip in.

I tried increasing the burst knock retard settings to try and get rid of it, but it didnt help. Ive also tried decreasing them and it gets worse...

Feel like this bigger displacement motor is not getting the fuel it needs on tip in and thats causing knock. A classic acceleration enrichment table would be perfect but gen 4 doesnt have anything like that right?

[schpenxel]

I'm in a rush so can't type the full explanation right now, but the short version is there ISN'T knock retard on tip in in the last log you posted. There were only two relatively small spots where you had any "real" knock at all. The max was 2*.

Everything else you see is being caused by something else. Burst KR or who knows what. "total knock retard" includes things that aren't actually knock.

Again, what you are seeing is not actual knock retard.

Transient fueling controls fuel on tip in / tip out. Easiest thing to change is manifold volume, try increasing is 20-30% if it's lean on tip in and see what happens.

I could be wrong if your latest logs are different, but this is 100% true based on the last log you posted.

Red is real knock retard from the sensors detecting knock...

Green is "total" knock retard that includes things like burst KR and some others. The red one is the one you need to worry about as far as actual knock from the knock sensors goes.
Untitled.png

[MrTurbo]

I'm in a rush so can't type the full explanation right now, but the short version is there ISN'T knock retard on tip in in the last log you posted. There were only two relatively small spots where you had any "real" knock at all. The max was 2*.

Everything else you see is being caused by something else. Burst KR or who knows what. "total knock retard" includes things that aren't actually knock.

Again, what you are seeing is not actual knock retard.

Transient fueling controls fuel on tip in / tip out. Easiest thing to change is manifold volume, try increasing is 20-30% if it's lean on tip in and see what happens.

I could be wrong if your latest logs are different, but this is 100% true based on the last log you posted.

Red is real knock retard from the sensors detecting knock...

Green is "total" knock retard that includes things like burst KR and some others. The red one is the one you need to worry about as far as actual knock from the knock sensors goes.
Untitled.png

Thank you for the continued help:

My fault, I was so used to this being a consistent issue I just kinda threw up my latest log without going through it, and forgetting that this issue has gotten much better since I started running a blend with e98 and 91octane, another reason I felt it must be legitimate knock. This 11:1, 416 motor does not like the load of a truck combined with 91 octane, although when the IAT's drop below 60 or so its much better, kind of excited for winter.

On older logs its very consistent with throttle tip in. What I am logging is "knock retard" as opposed to the Total Knock Retard, I think? lol picture below shows what i'm talking about with 4.2*
tip-in knock.jpg

YES! I figured it would be something in the transients and thought about the Intake Manifold Volume, abut I was hesitant to just start changing things... Thank you very much for that, gonna give it a shot right away, anbd will post up if it helps.

[GHuggins]

Mind posting one of the older logs then?

Also highly recommend the same as Carson, Add all of the knock or timing retard and advance pids to your channels - also looks like you need to add cylinder airmass for your histograms to work properly and then as also recommended previously go to the knock retard histogram and change the knock parameter to actual knock and not spark retard... This will help you better get a grasp on what's going on...

Since you've got a bigger engine displacement combined with different heads that's obviously changing all of the wall wetting factors of the transient fueling, your going to need to change your transient fueling for the new setup - ALSO do as Carson recommended here and focus on manifold volume as this hits things on a big scale and all fine tuning of this is done within the individual tables themselves... You might even want to look up a stock ls7 from a 14 z28 and get all of the transient fueling tables from it since head flow and displacement will be about the same? Haven't watched a log, but I would also be leery of using stock injectors on a build of this magnitude unless your using some from a blower motor or something?

Just some observations...

[GHuggins]

VE also doesn't appear to be touched = controls all transient fueling as a base input... Air modes are also still using VE up to 3900 rpms, so you'll want to tune in the VE - especially with your mods... Timing looks strange - possibly too advanced down low for the cam and cylinder pressure from the getgo - again look at a ls7 for guidance? Under Timing - AFR - gas and alcohol - you might want to zero those out so your not chasing your tail with weird unexplained timing...

[MrTurbo]

GHuggins
Mind posting one of the older logs then?

Well SCHPEXEL was right, and once I finally understood what he said I just realized, yeah I has just loggin the total KR so that wasnt burst knock, it was the burst knock retard that I increased showing up as all the spikes. That stupid SAE option that it asks you to switch to for each channel is what screwed me up! THIS WHOLE TIME DAMNT - Well I guess I can turn the Burst knock back to stock, or maybe a bit less even.

Yes I know the VE is pretty much stock, I added 12% across the board, and had been doing everything in MAF as I hadnt had the time to adress the VE problem I had been having and it was running well as it was, or at least I thought I was using MAF; I had thought when you had the Dynamic Airflow Disable set at say 4000 rpm, anything over 4000 was using the VE, and below the maf, apparently its the opposite of that from what you said?

Air modes are also still using VE up to 3900 rpms

Well damn if thats so that could explain some things

Regardless the fuel trims were pretty close (3-8% +/-) in closed loop for the most part, and pretty spot on to 12.5 afr at wot.

That said, I DO want it tuned properly in VE and MAf so they work together as they are supposed to. I tried again today to get the VE dialed in closer, and I must be doing something wrong, as the more I posted in from the stft+ltft error histogram table I made, the further off things got.

I wasn't doing steady state on a dyno by any means, but I was using care to try and keep things smooth... this has always slowly but surely gotten me close to 3-5% on the ltft before?

Here is what I did;

1. Disable the MAF by setting fail limits of 10hz and 9hz
2. Set all the maf related DTC to first error
3. Set Dynamic airflow disable to 7000 and 6900 (it did throw the maf code upon startup)
4. Zero out the entire maf table, so I know its not using the maf (thanks Schpexel)
5.reset fuel trims in scanner
6.Drove for distance trying to smoothly hit as many cells in the ltft+stft histogram (yes I confirmed the AXIS match the VVE
7. Afterwards I copied the values and did a paste special multiply % by half into both the switch open and switch closed VVE tables

Before I started I added an additional 14% across the board on both VVE tables and it got me really close, within 5-7% on all the cells I was hitting. But as I kept pasting the new numbers in, it got further and further off?

AS to everything else you said:

Since you've got a bigger engine displacement combined with different heads that's obviously changing all of the wall wetting factors of the transient fueling, your going to need to change your transient fueling for the new setup - ALSO do as Carson recommended here and focus on manifold volume as this hits things on a big scale and all fine tuning of this is done within the individual tables themselves... You might even want to look up a stock ls7 from a 14 z28 and get all of the transient fueling tables from it since head flow and displacement will be about the same? Haven't watched a log, but I would also be leery of using stock injectors on a build of this magnitude unless your using some from a blower motor or something?

I do have stock heads; this is a 416 with longtubes, full exhaust, and a coldair intake. Everything else is stock, including heads, cam and intake manifold.

Timing looks strange - possibly too advanced down low for the cam and cylinder pressure from the get go - again look at a ls7 for guidance? Under Timing - AFR - gas and alcohol - you might want to zero those out so your not chasing your tail with weird unexplained timing...

I have spent a lot of timing dialing the timing in to what is as close to MBT as I think it can get without high dollar equipment. Logged hundreds of miles making adjustments between knock limit and what seems to deliver the most torque. Yes I know that more timing isnt always better just because its not seeing knock. The motor seems to run really well at those settings, and the gas mileage has been great (this is a daily) at 16 city and 24+ hwy considering how big the motor is and its a truck. I get better than stock economy with a much bigger motor.

Thats my reasoning on the timing at least, but on the flip side im clearly a beginner, and respect what you guys have to say, and greatly appreciate you taking the time to help me, so please tell me if after seeing my reasoning you still disagree.

New log and tune attached

6.4.hpl6.4.hpl6.4 Maf enable.hpt