And its probably false.

I have been getting some knock for a while now. I have a LT4 KM and I think the sensor is desensitized a little through the PCM with a dyno tune. I have checked the spark plugs and made sure no high voltage wires run next to the KS wire, I have checked the motor mounts, I have put in 100+ octane and I still get knock.

It useually happens when the motor is cold, like when i pull out of my neighborhood, I have to get up to 45mph pretty quick, so I useually get some knock. Like sometimes it happens right after the 1-2 shift, I will get about 3-4 points but then it will slowly die down. It is RPM specific, and I can recreate it sometimes. Ive seen as much as 12 on my scanmaster, maybe more. But useually I only get up to 4.

I dont have access to a dataloging device yet so its just my scanmaster for know. I think the highest my spark advance goes up to is about 44. Does anybody have some sort of graph that shows how much spark advance you can safely run. I have a dyno tune with a little more aggresive spark advance, but I always run 92 octane. I think we tried lowering the spark advance to see if it solves the KR problem, but it didn't help.

I have a new knock sensor sitting in my garage, but i have been waiting until I flush the coolant to change it out.

Is there anything else I can check to verify if its real or false and to hopefully track it down.

 

You can run a higher octane fuel. Do you have anything rattling or banging while you accelerate? Have your tuner take like 5 degrees out and if it still gives you the same knock retard values, have him zero out the knock retard tables and be done with it.

 

Lt4 will not do any good as it is tuned for specific things to tune out. If ya don't have those things(sounds) then it does nothing.
It sounds like ya got false knock,so look for anything touching or vibrating.

 

Get a good spark plug reader, the kind with a strong magnifier and a light. Detonation will show up as tiny specks on the porcelain. If it is detonation you should be able to eliminate it by reducing ignition advance.

You could be experiencing piston slap, this is common before the engine reaches operating temperatures. Piston to bore clearance is large and cold fuel separates in the squish zone.

 

I thought about mentioning that, but I didn't know if the spots would still show up with the PCM pulling timing as fast as it does.

This is common in LS1's. I've never heard of people having the issue with an LT1.

 

If it is detonation that the knock sensor is picking up it should show on the plugs, even if it’s light knock.

That depends on the piston in use, with a forged piston and required piston to bore clearance, piston slap could be the problem, not likely with hiper pistons.

 

Stock motor and internals. My tuner has tried lowering the spark advance and we still had knock. No unuseually sounds when accelerateing either. I think he messed with the knock retard tables already, not sure exactly what he did with them though. 92 octane is the highest non-race fuel I can get around here.

 

You need to determine if what you are hearing is detonation, I'd read the plugs.

If it is detonation you should be able to tune it out, it's possible it's running lean at that point causing the problem.