Knock Strategy

The FK8 ECU has a significantly different strategy for handling knock compared to other Honda ECUs. It is extremely short lived, resetting fairly quickly and usually as soon as the throttle is released and reapplied. It does not have a memory. Contrary to popular belief, on an FK8 there is no learning over time, i.e. the Knock Control sensor on any other 10th gen Civic.

Take note of this, because it means that running the wrong fuel or improperly tuning ignition advance can be more dangerous than other cars. The ECU does not adjust over time and will still allow the initial knock it is detecting to occur every time you apply throttle. Even if additional knock in the pull is prevented, knock has still occurred.

While this seems counter intuitive, the knock sensors are also extremely sensitive and the ECU will intervene much sooner with more incremental steps of ignition retard that don't significantly reduce power. It is normal to see a few degrees of knock retard in one or two cylinders at a time scattered about a datalog.

While this strategy has the downside of not protecting as well over time against bad fuel (i.e. using 87 octane) or bad tunes (i.e. too much ignition advance in the first place), it has the benefit of more rapidly responding to and stopping random knock events when they do occur and then getting out of the way just as fast once the problem is gone. Due to the dynamic nature of the Type R ECU, it's almost impossible to test every scenario and knock can still occur from time to time on even the most thoroughly tested of tunes. This strategy, like many other FK8 ECU strategies, focuses on allowing the engine to perform at it's peak as frequently as possible.