Knock

Race Core F7 has two dedicated knock inputs with on-board band-pass. These are not generic analog pins. Use them.

Sensor

• A resonant knock sensor (OEM Bosch/GM style) is the usual choice. Broadband sensors work if the firmware filter is set to the bore's knock frequency.
• Knock frequency is roughly 900 / (pi * bore_mm / 2) kHz-order — in practice you pick the firmware preset for the bore or measure it.
• One sensor on a four-cylinder, typically on the block between cylinders 2 and 3. V8s often want one per bank (Knock 1 and Knock 2).

Wiring

• Signal to Knock 1 (C34) / Knock 2 (C35).
• Sensor ground and the cable shield to sensor GND (C8 is a convenient neighbour).
• Shielded cable the whole way. Route away from coils.

Setup

Knock is a correlation exercise, not a checkbox. On a dyno:

1. 01Set gain so light detonation is visible in the knock logger and a clean pull is quiet.
2. 02Confirm it is knock, not a rod or a noisy accessory — a timing cut of 2–3° should make the spike disappear. If it does not, you are listening to mechanical noise.
3. 03Then enable retard tables with a conservative cap (6–8°) and a restore rate. Knock control is a safety net, not a tune strategy. If it is always pulling 8°, the ignition table is wrong.