Knock Control（爆震系数）
本页面最近一次更新时间: 2024/01/22

Knock Control #

这个值字面翻译叫做：爆震指数，在 What is Knock Count and Knock Control (defined) 一文中有如下解释：

“Knock Count” = This parameter is a reflection of the ECU’s misfire monitor. It is NOT an accurate reflection of anything other than misfire events. When will you see these normally? Startup, rapid throttle closures, rapid throttle inputs, rapid release of the clutch pedal, and sometimes at idle (especially if you have a lighter flywheel/clutch combo, and/or plugs that have been gapped down to prevent spark blowout at high load). A completely stock car, operating perfectly will still accumulate these counts. In my experience with these engines, you will see more activity on cylinder four compared to others, as the crank position sensor is physically located closest to there on the block. This usually isn’t a concern area unless you see a steep count in a very, very short time (like 50+ in a few seconds), which will likely trip a P0300-variant DTC code.

“Knock Control” = This parameter is the ECU’s determination of fuel quality. Movement here indicates the knock sensor hears what it thinks is knock activity, and reports to the ECU to apply a steeper ignition retard to avoid continued knock activity. This value is dynamic, and WILL move from time to time. On Civic Si models, there doesn’t seem to be a forced rise at play at WOT like the non-Si 1.5T ECU’s (which naturally rise above 5,200-5,400rpm regardless of sensor input). Movement that goes up and up and up and never comes down is more concerning than movement alone. Knock control can typically be manipulated down by driving the car in a higher gear at lower engine speeds and targeting atmospheric pressure on the MAP sensor reading.

在另一个帖子（ Has anyone used the Hondata +6 PSI tune on CVT with Regular Fuel ）中，有网友表示

I really hate when people claim these cars don’t knock. The computer will do what it can to prevent it based on estimate algorithms combined with knock sensor activity but it surely isn’t ideal to have any knock control higher than the 49% or 54% depending on which tuning software your running. Period. Even stock.

从以上帖子的中我们可以总结出以下结论：

  • Knock Control 的高低取决于：油品质量，是否 WOT（节气门全开，可以理解为满油门），和通过爆震传感器得到的数据
  • 1.5T 非 Si 的思域的原厂程序会在 5000-5400rpm 及以上调高 Knock Control 的值
  • 激烈驾驶后 Knock Control 会变高

我们来看看原厂（这里的原厂指用 HONDATA 程序的 「Return to Stock」的程序，不一定是真原厂，因为真原厂程序在第一次刷之后已经没了）的 Knock Control 和 Knock Count 的曲线：

对比 +6 psi 的曲线如下：

可以看出来原厂的默认 KC 较高，在 89% 左右，但是在驾驶中没有 Knock，而 +6 psi 程序的 KC 比较低，一般在 60% 以下，但是会出现少量 Knock，当然，这样应该没啥问题（见上文：This usually isn’t a concern area unless you see a steep count in a very, very short time (like 50+ in a few seconds)）

关于这里 KC，在 Hondata 论坛上也见到类似的讨论，参考： https://www.hondata.com/forum/viewtopic.php?t=24625 「Thank you.But when I chose the “base calibration”,“K.control” will be “60%-80%” and “K.count” will be “5-20”,Is it safe?」 「Since ‘base calibration’ runs the same as the factory ECU, as safe as the stock ECU.」