What is the difference between those knock PIDs ?

[wesam]

I want to know what is the difference between those knock PIDs specially in E92 :

GM.KR_B , GM.KNKRET , GM.KR

Thanks in advance

[GMPX]

I just had a quick look and from what I can tell it is just GM rolling out different Knock PID's over different controllers throughout the years.

GM.KR_B seems to be specific for the old LT1 engine (not the current LT1, the old one from the 90's) with a resolution of 0.0625 degrees.
GM.KNKRET with a resolution of 0.17578125
GM.KR with a resolution of 0.088

I'm not sure why they needed so many different ones, but I think GM.KR is probably a good choice because that seems to be used on a lot of controllers for a long time.

Cheers,
Ross

[wesam]

Thanks Ross for your quick answer
The reason i ask
There is a total knock PID and real knock PID in hptuners
The total knock PID will log all retards like torque managment,burst.. etc
So i want to know which PID we have that will log just the retard due to knock
I'm logging GM.KR but some times its show KR but not polling timing so i thought there is aome other retards added to the real knock

[GMPX]

Right I see, in that case you'll find 'GM.KNKRET' is the one that shows all retards (well, the highest of all sources), and GM.KR will be showing the instantaneous retard just from knock.
I think I remember we looked at the relationship between the GM.KR PID and the final spark PID and the GM.KR is NOT factored in to the final spark PID (yes, very odd).