what techniques used to deal with sensitive knock sensors in E38

[wesam]

What techniques used to deal with sensitive knock sensors
What tables could be modified and how much amount ?
usually I increase B1906 by 50%
Some people disable the Burst knock and keep it disabled

[gmh308]

B1967 - B1974. You can desensitize by increasing the values (even GM sets some engines up with 7-8 and up to 16 >> 25) for them where ever you are getting what you think is too much KR. Until you get too much real knock :). With your engine being a lot noisier than a stock engine i.e. with headers and cam and it doesnt say so but if you are running 11.2 CR you probably have forged slugs and these are noisier too.

Burst knock is simply predictive knock for rapid throttle movements to get in ahead of and prevent real knock. It does sharpen up throttle response if turned off but can cause more aggressive knock scaler to be learned due to additional real knock that is likely when burst knock is off.

[wesam]

One more question why B1967 - B1974 has different values ?
I heard of some people make all those 8 tables the same

[gmh308]

One more question why B1967 - B1974 has different values ?
I heard of some people make all those 8 tables the same

GM tunes the knock response across all those data points for each cylinder and each cylinder generates a different noise profile. Once the engine is changed noise wise in any substantial way, they all go out of the window so yes the tables being identical are as good as anything.

[The Alchemist]

I log all cylinder knock "channels" , rpm and g/s pids, do power runs after some initial tuning etc examine logs and start tweaking B1967 TO B1974 to drop out the noise (false knock). I have knock phones on listenin to the engine as well.
Once you work through the noise you can tweak timing for best Torque and keep monitoring the knock channels . Once 6 or more knock channels start making "knock" by say 1 to 2 degs you know you're borderline on the spark advance and may need to back off by a degree or so...Its a process but seems to work rather well.
Some cars have really bad false knock that can affect performance in the mid range...some the factory settings need little changing if at all.....this has been my experiance....
cheers,
Mike

[wesam]

How much % do you tweek B1967-B1974 usually ?
Also do you mean to log knock separated in each cylinder and if 6 or more have knock to retard timing ?

[The Alchemist]

say at 700mg , which is that same as 0.7g/s, at 5225rpm you have 2.873 in cylinder C, and you log a bit of false knock and all the other cylinders are dead quiet, you might tweak it to say 3 or 3.2, reflash and try it again and see if the false knock goes away. Yes I log all 8 cylinders knock, rpm, G/s and spark timing while doing this. As you tweak up the knock tables you may get to a point while adding timing that more knock channels start activating showing "knock" remember these are just fancy microphones listening to the engine. If you have a situation where all cylinders, or say 6 or more, show 2 to 3 deg of knock chances are that it really it knock. You'll never here it in the car unless its really really bad so never ignore the factory logging knock sensors :) hope this helps.
Mike

[gmh308]

I log all cylinder knock "channels" , rpm and g/s pids, do power runs after some initial tuning etc examine logs and start tweaking B1967 TO B1974 to drop out the noise (false knock). I have knock phones on listenin to the engine as well.
Once you work through the noise you can tweak timing for best Torque and keep monitoring the knock channels . Once 6 or more knock channels start making "knock" by say 1 to 2 degs you know you're borderline on the spark advance and may need to back off by a degree or so...Its a process but seems to work rather well.
Some cars have really bad false knock that can affect performance in the mid range...some the factory settings need little changing if at all.....this has been my experiance....
cheers,
Mike

Impressive level of detail Mike! :) Cheers

[EngineCalibrations]

say at 700mg , which is that same as 0.7g/s, at 5225rpm you have 2.873 in cylinder C, and you log a bit of false knock and all the other cylinders are dead quiet, you might tweak it to say 3 or 3.2, reflash and try it again and see if the false knock goes away. Yes I log all 8 cylinders knock, rpm, G/s and spark timing while doing this. As you tweak up the knock tables you may get to a point while adding timing that more knock channels start activating showing "knock" remember these are just fancy microphones listening to the engine. If you have a situation where all cylinders, or say 6 or more, show 2 to 3 deg of knock chances are that it really it knock. You'll never here it in the car unless its really really bad so never ignore the factory logging knock sensors :) hope this helps.
Mike
Apologize if it was just a typo or a massive misunderstanding on my part, but it seems unlikely that those units are correct. It would mean that only the right most column is used for anything involving anything but very low throttle steady state cruising. The right hand most column is 900mg. Even if each of the 8 cylinders were taking in 900mg of air, that's a little over 7g/s of air consumed by the entire engine. That's very very low throttle. And too little airflow to actually cause much damage due to knock. What am I missing?