N54 Knock Table Discovery Fund

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Narcosis

Specialist
Dec 14, 2016
95
Hudson, WI
just spent the day at BMW dealer... They had a gorgeous gray M3 CS and M4 CS sitting next to each other. On my lust list now.
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... :)
 

doublespaces

Administrator
Oct 18, 2016
7,447
AZ
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.
Is there a way to get the piezo output logged?
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
What would you be looking for exactly? The voltage? I will be adding various extra params to support tuning the tables.
 

doublespaces

Administrator
Oct 18, 2016
7,447
AZ
What would you be looking for exactly? The voltage? I will be adding various extra params to support tuning the tables.
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.
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
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.
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
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:

28579
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
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.
 

1FastT2

Private
Dec 22, 2016
30
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....
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
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.
 

jyamona

Captain
Free Vendor
Nov 7, 2016
1,020
Philly
I would definitely like some volunteers with knowledge of this process and the appropriate provisions for testing first. IJE0S or IKM0S first.
 

veer90

Lieutenant
Nov 16, 2016
914
West Nyack, NY
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....
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.
 

Sbrach

Corporal
Oct 2, 2017
224
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....
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.
 
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