6 degrees knock, and -0.4 octane adj, not ok right?

[COMpulse]

The short story is that I'm seeing 5+ degrees of knock retard on 93 gas under light acceleration (3-4 PSI boost), and a learned octane ratio of -0.4. If that is nothing to be concerned about, please just tell me it's normal and no big deal. But I've seen a lot of threads where people have their octane adjust pegged at -1.0 or close. And I think 6 degrees of knock retard is a lot and would indicate multiple knock events.

I finally got my car tuned a couple weeks ago. LMS 93, 160 tstat, 3bar, and new plugs. Totally geeked.

But I was always told that you don't tune or increase boost without monitoring knock. Now that I'm looking at knock and octane adjust, I assume this has something to do with the 'being held back' feeling I have from my car. I feel like I'm not quite at perma-grin right now.

So, what do I do?
1. It's totally normal, no big deal. Quit asking noob questions.
2. Fill up somewhere other than Meijer and monitor it.
3. Add some race gas and see what happens.
4. Change tune to stock and monitor it.
5. Change tune to a lower octane tune and monitor it.
6. Stomp on the gas pedal and see if it explodes.
7. Something else?

Car is a 2013 SHO pp with 100,000 on it.
Engine temp is usually around 185. Not running hot at all.
Car always gets 93 octane. Meijer or Speedway usually.

If it matters, I've seen the Octane adjust as good as -0.9 in the couple days I've been monitoring. Even today it went to -0.8 for a minute, so I tried gassing it a bit and it went to -0.37 and knock retard spiked. Then I decided I should ask someone smarter than me (or a forum full of smarter people).

Thanks for reading.

 

[SHOdded]

I would love to say option 1 but 4 is probably best. Option 2 if option 4 has normal behavior. Could ask for a 2 bar tune see how that goes. And check plugs for signs of oil leaks.

 

[krewat]

Did you ask Livernois?

 

[COMpulse]

So I swapped stock 2bar MAP back in and tried the 2-Bar 93 tune. Same issue with knock retard and LOR. Around 3-4 PSI of boost the knock retard goes up to 5%, LOR -0.4 to -0.7.

Then I tried the stock factory tune. No knock retard. LOR pegged at -1.0 after a mile or two of driving. I tried to get some knock and only had one blip. Nothing that moved the LOR.

So, this appears to be a tune problem? I guess I will contact LMS tomorrow.

Thanks for the responses. Any other thoughts, please feel free to share.

 

[SHOdded]

Hope LME can help! Doesnt need to be a MAP sensor issue anyway ...

 

[COMpulse]

I assume it's some issue with my car, since the Livernois tunes seem to be the go-to and have a great reputation.
I've been driving around on the factory tune, and did manage a knock or two on an entrance ramp to the freeway, that hit my LOR for a minute. But not the easily reproducible knock at light acceleration I'm having with the tune.
It will be nice if it's something easily identified, or something that can be tuned away. Even better if it's false knock that can be eliminated. I'm hopeful that once it's figured out I'll be loving my car more than ever. Until then, I guess I'll consider pulling the plugs. Maybe something will jump out at me.

 

[SaveMelMac]

My experience with other platforms is that knock at WOT is what you should be concerned with. Knock at part throttle is normal. I can’t say this with 100% certainty as I just got my sho and still reading up on stuff. The other platform I came from was Mazdaspeed 3 btw.

 

[ridered74]

Might want to run a couple tanks of gas from BP or Shell thru it and see if the issue goes away. With my 2011 I had sputtering issues twice while driving on the highway at around 65. Was mildly accelerating each time and felt the sputter. Once was after getting gas with fuel perks at giant eagle, the second time was with speedway gas. Switched to only using BP or Shell and never had the issue again over more than a year and 25K miles.

Whenever possible I go to a BP that has a dedicated 93 octane hose. If it doesn't have a dedicated hose, you are getting at least some of the 87 octane from the person who filled before you.

 

[COMpulse]

My experience with other platforms is that knock at WOT is what you should be concerned with. Knock at part throttle is normal. I can’t say this with 100% certainty as I just got my sho and still reading up on stuff. The other platform I came from was Mazdaspeed 3 btw.

I've seen some posts that indicate part-throttle knock is fine, and some that say no, or there's still a limit to how much knock is okay. But seeing the LOR go up toward zero, I'm pretty sure that effects timing until the PCM re-learns from driving at WOT or enough throttle to make the knock retard go negative again. I spend a lot more time at part-throttle than at WOT. If I was about to race someone, I think I'd want the LOR at -1.0 from the start.

I filled up at a BP on Sunday. Still back on the stock tune. Going to monitor some more values, check the CAC, plugs, etc. Then go back up to the 2bar tune and monitor some more. Sent a PM to Livernois on here yesterday, so maybe they'll have some feedback. If it's still registering a lot of knock, I'll try some race gas just to see if any knock remains. If it still registers knock on racing gas, I think that would indicate a problem with the vehicle.

I'd like to go further with this car, but if I'm already backing off from my first mod, I'm not sure how it's all going to pan out. Hopefully it's all just worry for nothing.

 

[SHOdded]

These threads may make for good reading:
https://www.ecoboostperformanceforum.com/index.php/topic,4833
https://www.ecoboostperformanceforum.com/index.php/topic,4637

 

[limited02]

@Livernois Motorsports

 

[COMpulse]

Thanks for the links. Pretty sure I've read those at least two or three times, along with a bunch of other threads about knock sensor chaffing, pipes rattling, dirty MAP sensors, sludge in the CAC, etc.

Got in touch with Livernois on Tuesday. They said some knock is normal and recommended I try the 91 3bar tune, which I forgot I even had. So far, the knock readings on the 91 tune are a lot closer to the factory tune. LOR -0.65 to -1.0. There are still spots in the throttle where I can induce knock, and spots where I can get the computer to add timing.

I want to get the most out of my car, so now I'm going to try going complete OCD to find the cause of the knock.

I figure I'll run the tank pretty low and then put a few gallons of extremely high octane into the tank. If nothing changes and it knocks on 100+ octane at part throttle, it's gotta be false, right?

I didn't want to post too much to this thread until I've had a little more time to test and investigate. If there is any development I will post it here.

 

[COMpulse]

Things got weird just now.
Car has been running real good today, thought I'd try the 93 3bar tune again.
Finished programming and the car says my gas tank is empty but my OBD reader shows 20%.

Flashed same tune again and the fuel tank on the dash shows correct again. 77 miles to E.

WTF?

 

[SHOdded]

Battery in your SHO is good? It is recommended to have it on a charger even so, when flashing tunes. Last thing you want to do is brick the PCM.

 

[COMpulse]

Battery was replaced two years ago.
I've been flashing with the car door open (it's hot outside), just pressing the Start button once for 'Run'. The car dings for the 'Door Ajar' the whole time.
When the fuel level showed zero, at first I thought maybe I left my car running or something. The DTE just said "-- Miles to E"
I restarted the car and drove a few feet. It said 9 Miles to E, and my OBD reader said 20% so I figured I'd drive to the gas station. When I got there (one mile away), it said 8 Miles to E. I re-flashed (this time with doors closed). Then it was fine. MPG stayed accurate the whole time.

 

[SHOdded]

Ok, just a thought. Batteries are one of the worst troublemakers today. They pretend to be all innocent LOL.

 

[Johnbigdog]

A pocket screw driver can be used to latch the door so the "close the door" chime ceases.

The fuel level sender is a direct input to the instrument cluster. PCM flashing should have caused a problem with the fuel level. Distance to empty and fuel economy stuff is another story.