thunder550

iTrader: (70)

Hey guys, I was wondering if any of you can help me out with my timing issues. I can see where the problem lies (burst knock), but I'm not sure what a good setting would be. My Delta air mass tables are all set to .02 grams, and my burst knock table is as follows:

RPM......Retard
0........5.0
400......6.0
800......6.0
1200.....6.0
1600.....6.0
2000.....6.0
2400.....6.0
2800.....6.0
3200.....5.0
3600.....5.0
4000.....3.0
4400.....2.0
4800.....2.0
5200.....2.0
5600.....2.0
6000.....2.0


In the pic below, the upper left PID is burst knock, below it is KR, then Run DMA.

On the right, the upper one is Spark Advance and the lower one is base DMA.

I'm not sure what Run DMA and base DMA are or how to change them, but from what I have read it seems like the burst knock tables (especially for the trucks) are very problematic. What settings should I use? At WOT my spark tables command 17* but I generally see about 13.5* or less.

I also read that burst knock retard can also cause regular KR, so I'm thinking that if I can get my burst knock retard taken care of that the normal KR will calm down a little bit too.

I am running 2-bar SD, mafless, EFILive custom OS 01270003.

Also - what are good settings to use for KR recovery rate? Mine seems incredibly slow to recover.

Tordne

I have found that 0'ing both the BKR tables has given me the best results. I find if I enable BKR I often will log upto 8* of KR. With the tables 0'ed I get almost no KR at all.

As for recovery rate my settings are below:

LABELS Knock Retard Recovery Rate (Multiplier)
RPM {link: SAE.RPM} Value
0 0.090088
400 0.090088
800 0.090088
1200 0.050049
1600 0.024902
2000 0.015625
2400 0.015625
2800 0.015625
3200 0.015625
3600 0.015137
4000 0.013428
4400 0.012939
4800 0.012939
5200 0.012939
5600 0.012939
6000 0.012939
6400 0.012939
6800 0.012939
7200 0.012939
7600 0.012939
8000 0.012939

thunder550

iTrader: (70)

Is ti dangerous to zero out my burst knock table? I understand why it's there from the factory, seems like it might be a little dangerous to zero it out completely? Ir will normal KR cover me sufficiently?

jimmyblue

iTrader: (11)

Log the CylAir PID (Dynamic Cylinder Air), export it to
Excel, make a tick-tick difference column and divide the
frame-frame difference value by 8 (if you are logging at
a 10/sec frame rate) to see the deltaCylAir value that
corresponds to the burst knock enable table basis. For
example if your CylAir PID column is H, in your derived
deltaCylAir column =(H6-H5)/8 and then copy/paste to
fill the column. This corrects for the difference between
scanner frame rate (100mS) and PCM main loop rate
(12.5mS). Compare the deltaCylAir values you see on
acceleration to your thresholds in the enable table. If
you choose to run timing that pings on hard tip-in, then
you can finesse the enable values to catch it at higher
pedal-mash rates and suppress ping that way.

Trucks that have PE delayed, need burst knock protection.
Trucks that are tuned like cars, probably don't. It can be
a useful tool to make what works best for steady WOT
pulling, not ping during unsteady-throttle driving. An
accelerator pump would be better, but it must have just
been too damn hard for the software geniuses at Delphi
to emulate a plunger and jet. Yeah.

thunder550

iTrader: (70)

I have PE disabled completely since I am running the EFILive custom O/S...I have a boost VE table that I am using instead. That being the case, do you think I'll be ok with BKR disabled?

Tordne

In a boosted app you might want to enable PE mode as the OL fule table only goes up to 100 kPa MAP.

thunder550

iTrader: (70)

The boost VE table goes to 285 kPa...I have a 2-bar MAP sensor...

Tordne

Yup VE table does, but comanded fuel does not go any higher than 100 kPa.

So how are you going to "command" say 12.5:1 AFR above 100 kPa? Don't confuse commanded fuel with the VE (volumetric efficiency).

oztrack

I have found the same zerod out burst knock settings and am getting much less knocl overall. This was the setting i just used to get 11.619/116mph from a baby cam at 3625lb with driver

jimmyblue

iTrader: (11)

Commanded should just stick with the last table value
(unless you were running a custom N-bar OS?). A 1-bar
MAP sensor will peg not too much above that anyway.

I would set the burst knock retard tables to something
modest (maybe 4-5 degrees) and use the thresholds to
apply it when you really need a crutch for transient ping.
But set it so high, for starts, that it is out of play, so
you can see if you need it; log / Excel as described, do
some mixed driving and try to find tip-in ping, determine
the line between tip-in, no ping and tip-in, with ping on
a delta CylAir basis and then set the thresholds about
there. All of this, after you're sure you like the basic
fueling and the spark map for all steady points on the
driving envelope. Stitches first, Band-Aid last.

thunder550

iTrader: (70)

My last column on the commanded fuel table (105 kPa) is 13.4 up to 1600 RPM then 11.5 from there all the way up to 8000...I haven't had any fueling problems running the motor up well into the boost VE table, it's always right around 11.5:1, so it is pulling the last column on the fuel table even when it's over 105 kPa.

I will try the Excel thing as well to find exactly where the delta air mass tables need to be set. For now, I adjusted the delta table from 0.02 g/cyl to 0.6 g/cyl which seems to have effectively disabled it. Thanks for the tips everyone, it helps a ton!