Knock retard question

accordgtr · Post by **accordgtr** » Wed Sep 02, 2009 3:18 am

Does the Knock sensor really record knock? Can it mistake my clutch-type LSD or something else for Knock?

I have racing stock B16A P30 that's shaved a little using 95 octane gas.

At 6188rpm, datalog show my Knock retard 6 degrees so my timing only 13 degrees?! This seems too low.

I started at around 26 degrees timing but it KNock Retard was also retarding it 6 degrees. I kept lowering my timing but Knock Retard stays.

I'm beginning to think it is not really KNOCK. How do I test this?

Post by **Spunkster** » Wed Sep 02, 2009 8:47 am

Do you hear knock?

kinetics · Post by **kinetics** » Wed Sep 02, 2009 1:30 pm

Make some detonation cans, and take a listen...

http://www.d-series.org/forums/diy-foru ... llars.html

I think there's some audio clips of what to listen for too...

accordgtr · Post by **accordgtr** » Wed Sep 02, 2009 10:10 pm

Spunkster wrote:Do you hear knock?

No I do not. Well, its a race car with just a resonator and straight pipe so its kinda loud. But it runs well and I don't hear any pinging, misfire or anything out of normal.

That's why I'm kinda suspecting its not really knock.

To eliminate the knock retard, I have to go as low as 14 degrees at WOT @6200rpm. Seems too low for me already and it's definitely costing me power. In my older datalogs I was running @25-27 degrees, which also showed the same "knock". But I can tell my acceleration then was a lot faster from, say 150-170kph.

I'm tempted to just turn off the knock return and just run a reasonable timing advance.

You think my knock sensor is just too sensitive?

Post by **Spunkster** » Thu Sep 03, 2009 9:35 am

It could just be mechanical noise. You can try disabling knock control and see if that helps, but make sure you aren't getting detonation.