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      02-12-2013, 03:56 PM   #1

Drives: m3
Join Date: Feb 2013
Location: NYC

iTrader: (0)

Factors inducing knock and reading it with BT

A related data-logging thread for those more knowledable than me on this s65 or even the s85 engine regarding which value on the BT tool are we using to identify knock? Quite literally there are about 5 or 6 parameters relating to knock in some fashion and the units are not making sense to me. Often in the KW and giving numbers in the 6000 range when knock does register. A good reliable value with the BT tool and the meaning of the value would be greatly appreciated.

Also I was wondering what else determines knock. I tried to do some more structured testing and used 100 octane to do some runs, IAT's were low and yet there is still some knock in the 7900-8200 range that shows up. However I have no idea how much timing its pulling as the values do not make sense to me. The road was consistently on incline which may have put the load on the engine and caused knock but the timing was hitting its targets for the tune.

So essentially if you are hitting timing targets and IAT's are cool, are these engines that sensitive to still be riding along the knock sensor and intervening even at low rates?

I realized now after logging how bmw was able to be so aggressive with timing targets as the ability of this system to register minute changes is so fast that it can constantly test the max timing to get as close as possible.