weitek

Thanks weitek, that's a relief. I looked at the rest of the logs from this morning (general commuting), and I noticed some larger numbers there too, at like 30% throttle, so I kind of assumed it was ok after the post, but it's nice to have an expert confirmation

 

I'll try your suggestion and see where that gets me.. thanks again!

Careful who you call an expert!

Welcome.

I don't want to hijack the thread, and I'm just getting started learning about how to tune, but I've done a couple data-logging sessions and I'm trying...

 

My question: I did a 1-3rd gear WOT log this morning, and I'm seeing the parameter "Knock Correction Advance (degrees)" get as high as 5.5 in 1st gear, 4 in 2nd, and 3 in 3rd.

 

I don't have good logs to post (will in the future), my only concern is the high numbers... So, should I lay off the throttle until I can learn/diagnose/log more? Am I doing damage by being frisky with the pedal?

 

I'm starting to understand more of this, but it's slow going and I'd hate to screw something up before I even get started.

 

If the log would help, I can post it.. the parameters I logged (and yes, I know these aren't optimum) are:

Knock Correction Advance (degrees)

Manifold Relative Pressure (psi)

Mass Airflow (g/s)

THrottle Open Angle (%)

 

.. Please forgive my ignorance .. and Thanks!

Knock Correction Advance is the ecu adding extra timing. It is not an indication of danger or a problem.

At the very minimum you should be logging Feedback Knock Correction + Fine Learning Knock Correction. Then if you see those values go negative that means the ecu is pullling timing because it senses knock. That is when you should be concerned.

I suggest logging the following parameters until you have a better understanding of what your car is doing.

A/F Learning #1 (%)

A/F Sensor #1 (AFR)

Engine Load (Calculated) (g/rev)

Engine Speed (rpm)

Feedback Knock Correction (degrees)

Fine Learning Knock Correction (degrees)

Ignition Timing Advance (degrees)

Ignition Total Timing (degrees)

Manifold Relative Pressure (Corrected) (psi)

Mass Airflow Sensor Voltage (V)

Primary Wastegate Duty Cycle (%)

Throttle Opening Angle (%)

I saw a fair amount of knock below 2500 rpm and 1 g/rev when I was on the stock tune, so I've pretty much just ignored it when I started tuning. Usually when the knock sum increments in my logs, it's from lifting my foot off the throttle.

I've seen that one too. Do we know why that happens? Like do you think it's just noise or a tuning issue?

My knock thresholds are even higher, around 1.2 load IIRC. I had the exact same problems, now I don't worry about it anymore.

Wow awesome. You just made my day.

I've learned to live with it.. I've spent a fair amount experimenting with reduced timing and adding fuel etc only to go back to my original settings in the end. No matter what I did, it would show knock at loads between .3 and .9 or so at 2400-3000 rpm. I could see a knock sum count of 3 or 4 just backing out of my garage/driveway. A typical 20-30 min trip could show a knock sum in the 30s.. I can almost make it do it at will in that range by applying and releasing the gas pedal. My WOT logs in every gear are always completely clean. I've been debating raising the threshold to somewhere in the .8 to 1 load range.

That's exactly what I've seen. It seems to be really bad on the LGT when starting off - Franz and I are pretty sure the clutch/throw out bearing is noisy. For my STI it usually only did it cruising in residential areas or on the highway. I also spent lots and lots of time experimenting, any it always happened no matter what I did. I ended up moving the knock threshhold to 1.05 load and above and have been super happy with it. It drives a lot better now since it's not pulling timing all over the place. I was just wondering if anyone else had found a better solution but it is nice to know I am not alone.

Great thread. I think I picked up a few tips. Thanks

Edit: What is the general consensus about knock during very low load/rpm conditions? I have my own theories about this and have taken some unusual measures against it but I'm curious what you guys think?

Example: Crusing on the highway at 70MPH with constant throttle input, manifold pressure at -8PSI, ecu reports feedback/fine learning knock and pulls from 2 to 8 degrees.

I've seen it on cars ranging from stock to stage 2/350whp level. No amount of reduced timing in the tune seems to have any effect on this.