Knock Sensing
Turbo Mini Forums

Hi everyone, I've been running a Bosch wideband knock sensor bolted to the top alternator mounting hole since I converted to EFI a year or so ago. I'm using it for knock control via my ECU and also for audio knock monitoring during tuning. I've got some recordings of knock through the sensor which might be useful to anyone else trying to calibrate a knock detection strategy in their ECU or just interested to hear what it sounds like through the sensor if they're planning to use one for tuning.

I've run some of the recordings through an FFT and found the main knock frequencies to be 8kHz and 15kHz. 8kHz pretty much ties up with the calculator on Phormula's site which is quite convenient (mine's a 1293 so 71mm bore).

The ECU detection also seems to work well - looking at the logs after hearing knock you can see spikes in the knock signal well above the baseline engine noise. My car is on a straight cut box as well so the background noise is quite big!

I've used the setup on two RR sessions now - one at SRE and one at Northampton motorsport. Neil at SRE seemed impressed with how sensitive the sensor was vs what he could hear without using it.

If anyone's interested in more details let me know and I'll try to figure out how to post the clips!

Edited by gcos93 on 17th Oct, 2026.