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I feel I have a fairly good grasp on what takes place when KR is being shown on your favorite scanner. My understanding is that the Knock sensors need to first detect knock in order to compensate by pulling timing. I would like to hear from some of you big dogs on your feelings on this and why it's bad, common causes, why you don't want it etc.

My two things are.. if you have high timing and you begin to see knock, what kind of margin of error is there.

Second, Many toss on a small pulley that is smaller than they should have and only see 7 or less timing due to Knock.. what happens when it reaches zero?

New people need to understand why you cannot simply slap on a 2.8 and run 17lbs of boost on a stock motor. :)

Anyway, just looking for more outlooks .. learning some new things from this site .. I like it :)
 

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BoogieQ said:
I feel I have a fairly good grasp on what takes place when KR is being shown on your favorite scanner. My understanding is that the Knock sensors need to first detect knock in order to compensate by pulling timing.
Correct. The presence of any knock retard indicates that the knock sensor has picked up knock (or a stray audio frequency). It picks this signal up via sound waves. It seems like an antiquated way of doing things, but it works. :)

I would like to hear from some of you big dogs on your feelings on this and why it's bad, common causes, why you don't want it etc.
Why it's bad: The mixture is actually igniting on the compression stroke before the piston is top dead center. This is actually fighting the piston, pushing it back down. Now you know why the stock pistons chip or why a "hole" can be blown through one.

Common Cause: There is one cause to knock and that is heat. Everything else causes the heat which causes the pinging or knocking. Excessive boost, not enough fuel (mixture will "flash" earlier), excessive timing, high coolant temperature, hot spark plugs... These are all contributors.

Why you don't want it: If the engine is fighting itself, you not only make less power but you are taking a serious risk of damaging things in a most unpleasant manner.

My two things are.. if you have high timing and you begin to see knock, what kind of margin of error is there.
Timing greatly reduces the margin of error. When an engine blows with excessive timing it generally experiences a more dramatic failure than an engine would otherwise experience. You more or less have a piston that's further down in the compression stroke that and is going to have a harder timing fighting pre-detonation if it happens. For this reason, a little knock on a motor running 15 degrees advance is a lot more safe than a little knock on a motor running 22 degrees advance, though any level of knock is never "safe" though less is "safer". :)

New people need to understand why you cannot simply slap on a 2.8 and run 17lbs of boost on a stock motor.
Some you can teach; some don't want to learn. This is why we have replacement pistons/ blocks/ etc. :)

Anyway, just looking for more outlooks .. learning some new things from this site .. I like it :)
This site definetly has some potential. I would like to see some more consistent traffic through here.

Edited 643 times for correct spelling and better articulation. ;)
 
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