at idle my knock readings are 0-1 then as i drive the knock readings increase with the speed of the car. The faster i go the higher the knock readings. Up over 100 knock at 70+. around 30 mph the knock readings are alot lower. The revs don't seem to make much difference. I retarded my timing alot to see if that would change anything but it's the same so i put it back. I can't test under boost yet cause the engine is still being broken in.

I've determined its most likely noise. But what could cause the knock to be determined by speed? If it's drive train noise it seems it would be high regardless of speed. My cruise AFR's are fine, and i have a transmission brace which i heard can increase knock readings.

 

well it must be drive train noise due to the fact that your not even able to boost the engine. try taking your tranny brace off and go for a drive to see if that fixes the knocking. let us know your result if u do this cause i want a tranny brace aswell but having false knock readings is a pain in the ***.

what tranny brace are u running? i am having trouble finding one.

 

I made my own brace. I just cut 3 rectangle pieces out of steel. Drilled holes then ran half inch steel to each rectangle tack welded it bolted to the car then took it loose to finish welding it. Painted and bolted back up.

I won't be able to remove the tranny brace for a little while, the pit i use to work on the underside of my car is flooded right now. If that removes the false knock readings i might try some rubber washers.

if the knock is speed dependant more so then rev dependant, would that seem like a noise coming from the driveshaft or rear end? could it travel that far to the engine and be picked up as knock? cause if it was something in the transmission or something loose it seems like that would be more based on revs. Thoughts?

 

I had the same problem...70mph, knock 108. I backed off on the timing a few degrees and added some fuel...knock stays the same as idle(0 - 1)!!!!

 

well i backed the timing off alot i backed it down to 11 in cruise and the knock was unchanged. pretty sure mine is noise. im running the base map in cruise areas with a little fuel removed, to get a leaner afr and better economy.

 

supid question but where should the knock be at? what is the most before you should be worried?

 

I think it depends on if it's noise or actual knock. Posting back on my issue... I restarted my laptop and it stopped logging knock like that. Now it never shows more then 1 on knock. I think my knock sensor is screwed up.

 

Not a stupid question. Every car is a little different, you'll have to sort out what is noise VS what is a real knock. Once you have a couple of datalogs for your setup you'll know right away by looking for spikes in the time trace. Some say 40 knock is bad. Others say 60, on and on.

 

You can get high fake knock due to light unnoticeable mis-fires.
It has happened to me.