I understand all of that but this EFI isn't mass airflow based, it's MAP based, with the exception of the VEs. Also the oxygen amount varies exactly with the change in air density, so that's already baked in.

The areas where I'm getting knocking are within closed loop, so even if the VEs were off, the CLI and AFF are adjusting to keep the AFR at 14.3(0.976) which should be plenty rich. Besides, if you take a sea level tune and go to higher altitude, you would be running richer, not leaner. I will revisit my fuel tuning, but I think I've just explained why there's no way I'm running too lean. If anything I'm too rich.

 

and running a spark plug that is notorious for causing your exact symptoms....get the stock 6r12 plugs and follow Steve Coles advice,,,,,if there is anyone here on this forum that know how to help, it is him!!
m

 

Steve makes tuners for a living , listen to him. Get the fuel tables sorted and retard some ignition, unless you have excess carbon in the heads causing hot spots, .Also a thicker head gasket may help, and lastly use boostane to help fight knock. The closed loop section, is only reliable if the setup is correct, unless you are comparing it using and external AFR meter to verify. If it is accurate twiddle the timing

 

Source on that? I went to the dealer looking for the 6r12s and they only had NGK, which means they are acceptable as OEM.

 

I'm fully aware of the product he sells, but I also fully comprehend how this stuff works. I feel like you guys aren't reading my entire comments. Basically what I'm saying is that I know for certain that the fuel part is good to go, even on the rich side. There's NO way I'm running too lean. O2 sensors are brand new. If you had read my very thorough initial post, you'd know I've already retarded timing, a lot. The whole reason I reached out is because I've done everything I'm supposed to do and it's still not helping. I'm a pilot and aircraft mechanic professionally, so this stuff isn't greek to me.

 

try using the boostane and see if the knock goes away, if it does, then get a thicker head gasket, if it doesnt then its phantom knock, may be its coming from the drive train instead

 

 

Look, obviously increasing the octane will make it go away...remember I came from using 93 and didn't have knocking issues. The 91 is the problem, not my tune or the altitude(which should have made it less of a problem.)

It's not phantom knock because 1) I hear the knocking and 2) ion sensing doesn't "listen" for a sound, it detects it through ion buildup, caused by detonation.

 

well only option is to either run the octane booster until you get better fuel of run less compression via the head gasket.

 

or change the plug like Marco suggested