How much Knock is acceptable?

[Blown WS6]

I'm getting information from lots of people saying zero is the only acceptable answer and then some from much more reputable people saying some KR is ok and its a nuanced answer. I'm getting a huge amount of KR at idle but I think its my Y-pipe hitting my SFC (they are very close). But I'm more concerned with the 100% load column where is have a few degrees in the 3k RPM range. I have my fuel AFR dialed in at 12.5:1 the whole way through WOT.

I will attach the WUD display for a 20 minute drive to work with a few WOT pulls once traffic cleared. One screen is SR Peak and the other is Total.20220427_162616.jpg20220427_162624.jpg

[tayto]

fix your exhaust if it's hitting

[Blown WS6]

fix your exhaust if it's hitting

Yeah I'm not worried about that. I just moved the KR RPM enable to over 1000rpm and it fixed that. It only hits at idle.

[tayto]

thats probably not the case

[steveo]

your engine is a see saw, so if it hits at idle, it must hit at some point between accel/decel too. you must determine if your knock is real or fake before you decide how to deal with it.

a few degrees of knock retard is definitely okay, especially at lower loads, or if you get some crappy gas, but i would say NO knock retard is okay above lets say 70kpa on an n/a engine

i see in your log some stuff like 10 degrees at WOT and 26 degrees at cruise, that's not even remotely okay. you need to fix that.

you do realize that when you see knock retard, it's removing your programmed timing advance, right?

if your engine is truly retarding 10+ degrees of knock at 100kpa (full load), every time that's happening, it's probably putting a few microscopic craters in your piston and eventually that will become a crack that breaks things.

[Blown WS6]

Wow.... thanks for showing me you don't know how to read the tables! Lol. That 10 and 26 you are reading is total degrees of timing the ECM have pulled over the ENTIRE TRIP. The maximum timing its even allowed to pull on one event is 8 degrees. Lol.

That is why I also included the PEAK screen so you can see how much timing it has ever pulled in a particular cell in one event... jeez

[ralmo94]

I would fix the mechanical issue with exhaust hitting before being able to trust the sensor. If it's real knock you need to adjust your tables.
So you are saying that was knock counts with all the high numbers. Are you sure?

[steveo]

Wow.... thanks for showing me you don't know how to read the tables! Lol. That 10 and 26 you are reading is total degrees of timing the ECM have pulled over the ENTIRE TRIP. The maximum timing its even allowed to pull on one event is 8 degrees. Lol.

That is why I also included the PEAK screen so you can see how much timing it has ever pulled in a particular cell in one event... jeez

wow i am such a dumbass, man, thanks for letting me know. i've never seen whatever software you're using to view your logs, and it's hard to read since you're taking glaring pictures with your phone.

even your peak numbers aren't great. pull some timing.

[ralmo94]

wow i am such a dumbass, man, thanks for letting me know. i've never seen whatever software you're using to view your logs, and it's hard to read since you're taking glaring pictures with your phone.

even your peak numbers aren't great. pull some timing.

I think he's using an ebl what's up display.

Just in case anyone didn't know, to take a screenshot on a windows computer you can [control]+[print screen]. Then open Ms paint and paste clipboard, save as. Alot easier to see then taking a picture of a screen.

[tayto]

it's hard to read since you're taking glaring pictures with your phone.

ya this is usually a red flag for me

[Blown WS6]

I think he's using an ebl what's up display.

Just in case anyone didn't know, to take a screenshot on a windows computer you can [control]+[print screen]. Then open Ms paint and paste clipboard, save as. Alot easier to see then taking a picture of a screen.

Except when you are at work and they don't allow you to put your personal laptop on the company wifi. ����

[PlayingWithTBI]

Except when you are at work and they don't allow you to put your personal laptop on the company wifi. ����

There is also the "Snipping Tool" in Windows you can use.

You need to fix your "false" KCs 1st. Then add fuel and/or reduce timing. Are you running a WBO2?

[Blown WS6]

There is also the "Snipping Tool" in Windows you can use.

You need to fix your "false" KCs 1st. Then add fuel and/or reduce timing. Are you running a WBO2?

The Snipping tool doesn't matter when I can't post from the computer I'm running the WUD software from lol

Actually I don't need to fix that first. I can pull enough timing where I get zero KR at WOT so I know the stuff in the 100% column is real. I'm not worried about the KR at low load because I know its false because you can't get detonation from low cylinder pressures.

I was asking how much KR was acceptable at WOT. I don't need to answer any if these other questions but thanks.

And yes I'm running an AEM WB02

[tayto]

I was asking how much KR was acceptable at WOT. I don't need to answer any if these other questions but thanks.

I believe you probably already know the answer to this question... why don't you do some plug cuts and see if there is evidence of detonation or not?

[Blown WS6]

I believe you probably already know the answer to this question... why don't you do some plug cuts and see if there is evidence of detonation or not?

Yup found an informative article from one of the lead GM engineers:

https://forum.hptuners.com/showthrea...s-Pre-Ignition