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I have problems to configure knock control. Engine is 20XE Opel with little too high CR for RON98 and stock cams. Engine like knocking under some circumstances. We lower engine temperature from 95-100C° to 80-85C°. It helps a lot. But anyway there is danger. So I spend a day for knock sensing. Find frequencies by analyzing wav files, finding what means variables across wiki, Robs and Andrey forums. My frequency is 5.9kHz and 12kHz as harmonic. Try both with similar results. But there is big problem that I can solve: when knock occurs (very easy to hear) spikes come in both knockvalue and knocknoise. No matter how to configure window and then integrator time constants. Due this KnockDiff not changes significant. KnockDiff only becomes more noisy - not unusual at normal combustion too. But not give clear rising. For better analyze I even modify vemsV3.ini by adding Knocnoise and Knocvalue for datalogging. I use Specrtogram for analyzing wav, where real knock recorded. Center of spots are my mentioned frequencies. If frequency is chosen totally wrong, KnockNoise and KnockValue must not rising when knock occurs. But in real life there are big spikes during knocking on both. As I understand spikes is output buffered with given frequency only. Currently 1.1.27 firmware. Board #1437 Engine - slightly overbored 20xe. 86mm is standard bore. Msq http://www.vems.hu/files/GintsK/Config.txt http://www.vems.hu/files/GintsK/tables.txt Record of real knock: http://www.vems.hu/files/GintsK/KNOCK4.wav Not very usable wav of clicking wrench at diferent areas of block: http://www.vems.hu/files/GintsK/wrench01.wav '''Something is wrong here. It seems to be noise, not knock-sound'''. The spectrum does not have a peak at the knock frequency. To sense knock, the knockchip must listen to the specific knock frequency, not a wide-spectrum noise. The wrench method always works if the sensor is mounted and operates properly * is the knock-sensor bolt on properly ? * wired properly ? * between ** EC18 pin 2-3 (recommended) ** or using EC36 pin 26 as ground ? (could work, if otherwise the power grounds are wired properly) ** or other means ? (through endplate is possible. 2nd knock channel can be tried this way, although a 100nF and a 10-22k resistor is needed) * maybe there was also a problem with the soundcard mixer setting that was used for recording ? One more observation: if chose knock window start at 0° and length 60° there is no Knockdiff at all - 1.00 all the time. During experiments I found knock settings in LADA OE calibrations. Generaly window starts @ 6-18° and ends @30-42° at low rpm and @54-60° at high rpms (not window length, but end angle BTDC). *WikiAdvert: mailto:gintsk@inbox.lv
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