Posted by: DoberManJT
knock retard elaboration? - 04/07/05 11:06 PM
I'm looking to understand the full relationship between timing/power/kr/mods. Please, everyone add what they can to the topic to provide as complete and detailed information as possible. I am not an experienced mechanic, but am willing to educate myself given the information.
This is what I've gathered, please correct as needed...
The PCM is programmed to retard timing in the event of "knock" - or pre-ignition in the cylinders. Thus, the term "knock retard".
Pulling the timing results in loss of power - the more degrees of timing retarded the greater the loss of power. If the PCM didn't retard the knocking it would result in damage to the engine.
What are specific causes of "knock"? I don't mean " (blank) mod causes it" I mean mechanically what does that mod do that causes knock?
Certain modifications increase the risk of "knock" - the most commonly referred to KR-creater seems to be a smaller SC pulley.
"Colder" range spark plugs and intercoolers seem to be the most effective KR prevantives to a modified engine, why is this?
Not all engines are created equal, some are "KR monsters" and others seem to run the same mods without KR issues, why?
It seems that KR has got to be one of the top "power-killers" and yet so many people don't understand this issue, myself included. I think this info would be a great thing for Herc to have on his site.
This is what I've gathered, please correct as needed...
The PCM is programmed to retard timing in the event of "knock" - or pre-ignition in the cylinders. Thus, the term "knock retard".
Pulling the timing results in loss of power - the more degrees of timing retarded the greater the loss of power. If the PCM didn't retard the knocking it would result in damage to the engine.
What are specific causes of "knock"? I don't mean " (blank) mod causes it" I mean mechanically what does that mod do that causes knock?
Certain modifications increase the risk of "knock" - the most commonly referred to KR-creater seems to be a smaller SC pulley.
"Colder" range spark plugs and intercoolers seem to be the most effective KR prevantives to a modified engine, why is this?
Not all engines are created equal, some are "KR monsters" and others seem to run the same mods without KR issues, why?
It seems that KR has got to be one of the top "power-killers" and yet so many people don't understand this issue, myself included. I think this info would be a great thing for Herc to have on his site.