Transitional Knock?

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Crazi

Why Try...
Joined
May 26, 2001
Messages
541
Has anyone ever had any damage from transitional knock? I get alot of it if I try to nail the gas at highway speed. Alot being as high as 30 Deg!!

My engine seems to be ok but has anyone ever hurt anything from this? It normally knocks and then I let off and try it again but recently, it shook the car like it was missing a cylinder or two. I let off and rolled back into it and the knock was still there but went away because I only had about 1/4 or so throttle. My oil pressure looks good at 18-20 hot in gear but it used to be 24-26.

Should I change the bearings or at least check them out?:(

Engine has roughly 4000 on it.
 
Originally posted by Crazi
Has anyone ever had any damage from transitional knock?
My engine seems to be ok but has anyone ever hurt anything from this?

Yes.
Given time, it'll knock the corners off the pistons.

As long as you stay under the timing retard limit and the ESC is working you can get along fine.

GENERALLY the knock limits are set at 30d in non EGR mode, and 15d in EGR mode. Exceed those and you'll be buying engine parts.
 
EGR Mode? I have disconnected my EGR and have the powerplate in with no hole drilled.

Is EGR mode something in the chip?
 
That sounds like false knock. Transistional knock is usually only a few degrees and only with 23º or higher chips.
Throw some racegas in and see if it goes away. If it does then yes you have a big problem. If not then the knock is false and you have a bad motor mount or DP hitting or a loose IC, etc.
 
Isn't the burst knock retard supposed to take care of transitional knock? Does DS show the BKR in the timing?

Nick
 
The chip is 24deg. and only happens at highway speed going from cruise to half throttle or more. I have poly motor mounts, and the DP is fine as it only happens at speed.

I talked to my engine builder and he said check the bearings. Lets hope things don't look too bad down there. Guess I need a variable timing chip?
 
Hmmm. Now that I think about it, the RA chip I was using has a feature to ignore knock for 2 seconds before retarding the timing at fast throttle movements. DOH!
 
EGR?

If you have a chip which uses EGR, and you close off the EGR port, you will have transitional knock. There is too much timing set by the chip when it "expects" EGR, and that causes the knock. Make sure the chip is burned for a non-EGR engine.
 
WHEN YOU GUY SAY CHECK THE TORQUE ON YOUR KNOCK SENSOR IS IT SUPPOSED TO BE TORQUED TO A CERTAIN SPECK? AND WHAT IS THE DEFINITION TRANSITIONAL KNOCK ?
 
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