Thread: Thinking of converting to E85.. Yes or Ne??

Originally Posted by Ginseng

Again im just trying to understand this. The timing retard programmed in the pcm during shifts is torque management to save the trans life not to combat knock?. But does or doesnt show on a scan gauge as actually kr? If it did i imagine everyone would see kr during shifts but not everyone does. But i thought the scan gauges read timing retarded in degrees to combat knock. Now is kr on a gauge reading retard only during actually knock or false knock? or is it reading the actual knock or false knock thats accuring in degrees? Now its possible gm programmed that retard to combat knock that is more probable during shifts.

Edit: So if we took those values of what bill posted and set to zero would the car be more prone to knock or would it just put for stress on the tranny?

What Bill is saying is confusing an issue that really isn't even an issue.
The torque management system is just that... torque management. It has nothing to do with knock.
KR is either knock, or something else making noise that falls within the frequency range of knock.

This is 3800 101 here.
I'm sorry you guys are being confused by Bill.

This is a decent write up that seems relevant.
http://www.zzperformance.com/blog/ab...ock-retard-kr/

Originally Posted by Ginseng

Detonation: Detonation is the spontaneous combustion of the end-gas (remaining fuel/air mixture) in the chamber. It always occurs after normal combustion is initiated by the spark plug. The initial combustion at the spark plug is followed by a normal combustion burn. For some reason, likely heat and pressure, the end gas in the chamber spontaneously combusts. The key point here is that detonation occurs after you have initiated the normal combustion with the spark plug.
Pre-ignition: Pre-ignition is defined as the ignition of the mixture prior to the spark plug firing. Anytime something causes the mixture in the chamber to ignite prior to the spark plug event it is classified as pre-ignition. The two are completely different and abnormal phenomenon.

Exactly... and neither of these phenomenon have anything to do with torque management and vice versa.