false knock areas

[TheSlow1]

I'm working on adjusting my tune and I'm noticing allot of knock under lower load in the 2250-3500 rpm range. The knock really only appears to happen when i'm between .30 and .40 load. I know having long tubes can sometimes give you some false knock readings and i've heard that superchargers can do the same thing as well, so i'm kind of leaning towards this for my knock issue in this particular area. Of course i do see knock in a couple of other areas but it's more of a single spike during WOT tuning not a constant pull of timing while cruising and maintaining speed.

So, basically i'm wondering if there are any known false knock areas on the 3v, or if there is certain areas that i can just not worry about knock and only really worry if it's above a certain rpm or something like that.

Any help is appreciated.
Thanks, Larry

 

[dysan]

On mine looking at some prior logs I only seem to get a little noise when I would initially launch at the track when nearly dumping the clutch and then I almost always get it around 5500+ rpms up which Lito turned off the knock retard there since it's most likely a combination of engine and blower noise.

 

[Fullboogie]

Don't dismiss it as false knock. I had real detonation after the install of just an offroad h-pipe, verified first by my wideband and then by my tuner on a dyno. I've got an old post from 08 that chronicles the whole thing with datalogs, etc.

Our processors can be very finicky. Get it checked out before you blow it off as nothing to worry about.

 

[TheSlow1]

Well I don't want to just up and dismiss it as false knock but I have continued to drop the timing in my MBT table in the respective fields to the point that it's only commanding between 15 and 20 degrees. It has finally gotten to the point that the sensor is dancing up and down now instead of pulling a constant 3 degrees but if I continue to pull timing out I'll only be running around 12 degrees of timing while driving around in those load and rpm areas. From what I was told I should be seeing mid 20s for timing while rolling through gears or cruising at lower loads. Is this correct or am I wrong on that. When the supposed knock happens my air fuel is stil spot on 14.6 so that is also kind of leading me to believe its not actually knock. What are some ways to figure out if it's real knock or not.

 

[dysan]

PM me your email address and I can send you one of my logs so you can look through some stuff. Under light cruising loads my spark advance is 37-40 and under WOT I'm around 17 degrees with 15lbs boost and 93 octane fuel. Now I'm slightly lower than stock compression around 9.3:1 and I'm sure that makes some difference in the spark advance.