I’ll find a log but it is def correction cause it will be on 2 or 3 cylinders heavy and sometimes 1 or 2 degrees on others
N54 Knock Table Discovery Fund
- Thread starter fmorelli
- Start date
Yeah - the M4 has my full attention these days. I always buy used, have been surfing way too many of them. The E92 is right where I want it to be, modification & power & driveability wise, and then I get distracted. A 2016 coming off lease would be sweet...
Very good to know. So it might be as simple as tweaking the rpm/s or maf transient detection conditions to ensure an AT/DCT shift hits that condition, and then changing the transient noise averaging constant.
Correct, although I think someone else would be more qualified to say what is useful here and that sort of answers my question. If there are more parameters along these lines being added then I think this will be very helpful.
All tables for two rom versions should be complete tomor. I'll post a pic listing them all. Next is a few new logging params to help with tuning the tables, followed by some beta testing from whoever has dyno access and det cans / tools to properly verify things.
Last of the tables added: Amplication precontrol Cyl 1 - 6, and Amplification precontrol Cyl 1 - 6 (pre-window). I am leaving out the measurement window begin / end (in *CRK) as I don't believe these should need to be modified even in an outrageous built engine scenario. If for whatever reason they are deemed necessary or someone can provide a good argument for their necessity, I will add.
Anyway, screenshot as promised with some values to look at for the time being:
Anyway, screenshot as promised with some values to look at for the time being:
One other thing to note, going forward with XDF additions / new tables, I will always try to use the mathematically exact scaling from the code, no guesstimates / rounding. Additionally, the physical min/max allowed will be defined like you see above for each table.
One more for anyone who would like to start theorizing:
I guess here's the thing I'm concerned about. 1st and foremost, its awesome to have these tables discovered.
BMW engineers have spent 100's if not 1000's of house perfecting these tables for 1 engine, all built exactly the same.
If we were to use these tables in any fashion correctly, all of that research would have to be done over again for each built engine attempting to be tuned. All built engines are built a little differently. Maybe one set of pistons with another set of rods, or a different set of pistons with a different set of rods with a closed deck conversion. Everything going to be different from engine to engine. Even if someone does take the time to really go though and have a good set of working parameters certainly doesn't mean the same parameters are going to work with someone else's build.
Maybe I'm wrong....
BMW engineers have spent 100's if not 1000's of house perfecting these tables for 1 engine, all built exactly the same.
If we were to use these tables in any fashion correctly, all of that research would have to be done over again for each built engine attempting to be tuned. All built engines are built a little differently. Maybe one set of pistons with another set of rods, or a different set of pistons with a different set of rods with a closed deck conversion. Everything going to be different from engine to engine. Even if someone does take the time to really go though and have a good set of working parameters certainly doesn't mean the same parameters are going to work with someone else's build.
Maybe I'm wrong....
Like all tables in the bin, it's up to you / your tuner to utilize them properly. I think overall there could be some rough guidelines published if those who go through the motions wish to share. For example, general changes +/- a few percent for closed deck, sleeves, low comp, high comp, etc.
Definitely will need tweaking for different engines especially from different builders. Piston material, PTW clearance, ring material, ring gap, closed deck, sleeves, etc etc you get the idea all that affects what the knock sensor picks up.
Do you hold any other modifications or tuning to such rigorous testing requirements? For instance how have you compensated for the individual cylinder fuel trims after changing downpipes or even worse, going single turbo? Did you do all the math and testing to determine the correct values for phase delay between O2 sensors and compensate for the lack of oxygen storage capacity between the two sensors without a cat? Or do we just run lambda target at .8 for the bank and hope for the best?
As soon as you change anything those 1000s of hours testing a calibration for 1 engine are out the window.
