Kpro knock control explained

[The Spectacle]

Hondata - can you post a brief overview of how knock control (or the apparent lack thereof) is implemented in the kpro ecu? I've heard everything from its completely disabled to it does whatever it wants, you just can't see it. I've seen your posts where you say it is very complex...can you tell us why? I've personally seen the ecu do things with my timing that no one can explain, and I feel like it would benefit the community if the knock control parameters were explained in detail.

At a bare minimum, I would just like to know if the knock control tables ever going to be available to us to modify. You have a parameter for knock retard degrees but I've never seen mine or anyone else's read above zero...by design or what?

- D

[Hondata]

In brief the Honda knock control is designed to compensate for different octane fuel on a stock engine. Is of limited use to us because it will both retard without any knock and also not retard when there is knock, and requires extensive re-tuning for any engine modifications.

For more information on how Honda implements knock control see the FlashPro help file. http://www.hondata.com/help/flashpro/kn ... tables.htm

Currently in the KPro the knock control is mostly disabled for the reasons outlined above. However, since the release of the KPro 6 years ago we have a much better understanding of how Honda knock control works, and the plan is to add access to the same tables at the FlashPro (ignition knock limit, knock sensitivity & knock retard). This will take some time because of the way KManager software was never designed to allow arbitrary table editing like the FlashPro, and also because we need to maintain backwards comparability with both older calibrations and ECU downloads.

The answer to your last question is that are two types of knock retard - retard from the ignition knock limit being lower than the MBT ignition, and retard from the ECU determining that the octane is lower than optimum. The ECU knock retard variable only records the retard from the ignition knock limit. With the FlashPro I changed the ECU code to include both - this would be done with the KPro as well if possible.

Don't worry if this seems complex and confusing at first. When we released the knock control tables on the FlashPro we found that people took a little time to understand the Honda knock control, but eventually did.

[The Spectacle]

Thank you very much. The community will benefit from this information as well as the upcoming release of the knock control parameters. I will happily return my feedback when the software is released.

[The Spectacle]

Hondata - with your statement that kpro's knock control is "mostly disabled" right now, can you elaborate on which portion you left enabled? I would assume its the fuel octane reading portion

[eternallx]

This is very good information.

If you would please add the Dual ECU Kpro's knock reading/control ability also. Whether its different in any way compare to the pre-2006 S2000 Kpro's reading and control ability.

[Hondata]

"mostly disabled" - sorry, that's the best we can explain the knock control right now.
Dual KPro - works exactly the same as a standard KPro - I don't really understand the question you're asking.

[eternallx]

Sorry about the way I phrased it.
So the kpro can pickup knock but wont pull any timing because of it correct?

[Hondata]

See the FlashPro help file. The way Honda does knock control means that it will only retard timing from knock if the estimated fuel octane changes.

[The Spectacle]

Hondata can you comment on this thread and confirm whether the posts are accurate http://www.s2ki.com/s2000/topic/926411- ... mit-table/

I think what scottinal posted makes sense it would be helpful if you could provide concurrence with the explanation of the knock control implementation. TIA