Help with knock retard

[sixt9stang]

This is on my car, a 2009 Pontiac G8 6.0. Some background info in case it is helpful:
DOD Delete
Heads shaved .030
Cam Specs: 219/223 .625/.625 with 112 lsa
Stock manifolds

I do not have a wideband installed yet. I have the car running fairly well from what I have learned on here but I have a KR issue still. I noticed it on 87 octane and decided to run 91 premium no ethanol today as a test and still notice KR. It took a couple of drives for the STFTs to get back towards normal and then I took a couple of logs. I never went over 3000rpm during the logs. Also the temp outside was about 70F.

They are posted with the tune. Any help is greatly appreciated.

Thanks!

9-21-premium91kr.hpl
9-21-premium91.hpl
start-air-tqmgmt-disabled.hpt

[5FDP]

Have you logged burst knock to see if that is it.

With a cam like that you are better off just removing burst knock completely, as it just gets in the way.

[sixt9stang]

Thanks for the suggestion. I will look at adding it to my next log. If that turns out to be it I will look into removing it.

[sixt9stang]

So I finally had some time to do some logging. The attached log is on 87 octane shortly after a fill up. I also re-enabled LTFTs in the tune. I got on it a bit about 11 minutes into the log and have some nasty KR. Nothing logged with Burst Knock Retard though. It did go a little lean at the time but nothing crazy. Please help me figure out if this is just in my tune and that it needs work or if it is more than that.

I have also started reading about injector timing and started logging some stuff for that. Maybe between that and completing a VVE tune things would be better/safer?

10-2-KR.hpl

[Codes]

The knock is real, you can see it in the first log, can you log cylinder air, also try kicking in your PE, (lower your pedal settings a tad) the last log your at 75% load. Also add Base Advance Timing to your channels.

[sixt9stang]

Thanks. Made some changes and will post up a new log when I get a chance.

Another question. The more I have been reading, the more important it looks like changing the injector timing is with a new cam. If I do change settings for the injectors I will probably have to redo the MAF tune, correct?

[Codes]

Injection timing tuning for a change of cam does help, although in this case I don't think it is the knock problem. Changing injection timing may lead to re-tuning the Maf and/or VE, it would be a case of change and log, re-tune if needed.

You have bumped compression and changed cam and are running 87 octane, ie. A cocktail for knock. I would also pull a couple degrees of timing until you get on top of it, then re-tune timing.

[sixt9stang]

Sounds good. Thanks for all the help!

I also had knock with 91 no ethanol. I did not hit as much load when I was testing that though so I do not know if there was as much knock up top.

[sixt9stang]

Picture of Cam Specs attached. I have been looking at a lot of different cams that people use in G8's and so far this cam has more lift than any others that I have found. However it does not have as much duration. I do have a lot of valvetrain noise which I attribute to the lift and the valve closing. Could this trip the knock sensors at higher RPM?

G8CamSpecs.jpg

[sixt9stang]

Here is a log after some changes to PE. Also attached the current tune.
Was getting knock without even getting on it that much. Getting scared to even go over 2k rpm with the car. Hoping this can get straightened out in my tune and that it isn't mechanical. Thanks to anyone that can help.

10-5.hpl
PE-Idle-Changes.hpt

[sixt9stang]

Did some more scanning with 91 octane in the car and have started modifying the high octane spark table. I also started doing a VE tune with just fuel trims. Figure I will take it really easy on the car and get the fueling a little more dialed in.
This is the STFT + LTFT from the first scan today.
vetune1.jpg

[Codes]

Ok good, read up on building data filters, it can found in the Help section, that way you can filter out rubbish data. You can apply filters to a data log at anytime, you do not need the filters in the graph at the time you are logging.

Street tuning takes time, patience, logical data filters and a steady foot, especially tuning the Ve table more-so than Maf transfer table, steady state data is what you want. Apply filters and look for trends in your error graphs before making adjustments.
I saw the log in your other thread and the knock was concerning, it kind of looked mechanical, different to the logs in this thread, ensure the valve-train geometry is perfect. Can you hear any "Pinging"? It would be interesting to hear it running.

Another thing you can do is take a look at Ed Mowton ERM Performance tutorial, I keep pushing it but think it is exceptional value for money for people getting into tuning.

[sixt9stang]

That's the thing. I can't hear any pinging at all. I know what to listen for as I have heard it before on my 69 Mustang when I couldn't get Premium for it one tank.

It actually runs very well and strong. I think I might mount my cam in the engine bay tomorrow while driving just to see if I can hear anything on that. I can definitely hear the valvetrain while idling or driving slowly. I don't know if it is loud enough to trip the knock sensors though. It doesn't knock while just idling. I was thinking about copying my low octane table over the high octane table just to see if I still get knock. Attached is the log from earlier when I was scanning for the VE tune. There was some knock and I was definitely taking it very easy.

I was looking at the Ed Mowton site the other day and was thinking about purchasing it. Will look into it more.

VE-tune-1.hpl

[Codes]

When doing your Ve remove the maf pids from your channels. As a sanity check I would put stock timing tables back in and even still remove a couple degrees of timing.

[sixt9stang]

Sounds good. When removing timing, should I remove a couple of degrees across the whole high octane table? Or just where it is showing knock?

[sixt9stang]

I am going to do some more scanning with channels added to my scan for knock on all cylinders. If all cylinders show knock, lowering the timing should get rid of it. If lowering timing does not get rid of it, then it would be fake knock, correct?

[Codes]

Stang can you post your stock tune if you have it.

[sixt9stang]

No problem.

2009G8GTBASE.hpt

Also, I haven't written it to the car yet. But the next file I was going to write to the car has some changes to the Injection tables and I removed Burst knock just in case it is from that but wasn't being logged. Don't know if that is possible or not. I have to get up early for work tomorrow but if I have time I am going to mount the camera in the engine bay too. I also set up my scan channels for knock on individual cylinders.

[Codes]

Ok, can you also add Knock Learn to channels.

[sixt9stang]

I have that added too. It is in the log posted earlier named VE-tune-1. I attached another log too. They both show info in the knock learn factor channel. I just haven't had the chance to read up on what that means yet. Thanks for all your help!

10-10-91octane.hpl