how do you guys attack KR? Average or max?
09-12-2004, 10:01 AM
#21
In your first 2 example the injector pulsewidths were rising, so that part looks ok. Not sure why the o2 voltages dipped there... Unless it was just transition air that the pcm had not caught up with yet.
In the third example, one injector pulsewidth had dropped to practically nothing. You were also on a shift point, which might have some effect. Not sure why that side dropped so hard though.
In the third example, one injector pulsewidth had dropped to practically nothing. You were also on a shift point, which might have some effect. Not sure why that side dropped so hard though.
09-12-2004, 12:32 PM
#23
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
Injector has to rise faster than your mass airflow.
The MAF value cannot be relied upon when airflow
is changing fast because it is too slow an instrument.
You have to look at airflow as VE*MAP*RPM (or for
logging, just call VE 1). You could plot in Excel, the
quanitity (MAP*RPM/InjPW) and get a good first
order idea of the delivered AFR (scaled by who
knows what, but you could probably dope out a
rough correction factor by looking at a highway
80MPH cruise point and call it 14.7:1).
If you see that line spike, and the O2s dip, leading
the KR blip then it's pretty certain it's transient
mixture related.
The idea about using an elevated VE value to "cover"
the lean hole revolves around the fact that the PCM
uses SD above 4000 only in "unsteady MAP" intervals
and then you will go back to MAF and have whatever
you programmed there - so a faked VE table is kinda
like your accelerator pump shot. Which is what we
would really like, but apparently there is nothing of
that sort in the PCM code.
PE does have an enrichment rate field that should
be set to 1.0 (or more?). You do not want slow PE
roll-on with a fast-rev-climbing car.
Another thing - look at the profile of the open loop
fuel air vs MAP vs ECT table, particularly the vs MAP
columns. Be sure that the MAP at which you are
seeing KR (on my car, seems like it's the few cells
where the throttle is moving from ~20% to 100%
but has not gotten there, that are the initiators)
has a fairly fat multiplier. Look at the FAM PID in
your logs; is it 1.000 when you pop KR? If so, how
can you get earlier enrichment to come in?
This is a nagging question in my mind - what are
the trigger conditions for open loop and for PE?
Have yet to find the logic described.
you
The MAF value cannot be relied upon when airflow
is changing fast because it is too slow an instrument.
You have to look at airflow as VE*MAP*RPM (or for
logging, just call VE 1). You could plot in Excel, the
quanitity (MAP*RPM/InjPW) and get a good first
order idea of the delivered AFR (scaled by who
knows what, but you could probably dope out a
rough correction factor by looking at a highway
80MPH cruise point and call it 14.7:1).
If you see that line spike, and the O2s dip, leading
the KR blip then it's pretty certain it's transient
mixture related.
The idea about using an elevated VE value to "cover"
the lean hole revolves around the fact that the PCM
uses SD above 4000 only in "unsteady MAP" intervals
and then you will go back to MAF and have whatever
you programmed there - so a faked VE table is kinda
like your accelerator pump shot. Which is what we
would really like, but apparently there is nothing of
that sort in the PCM code.
PE does have an enrichment rate field that should
be set to 1.0 (or more?). You do not want slow PE
roll-on with a fast-rev-climbing car.
Another thing - look at the profile of the open loop
fuel air vs MAP vs ECT table, particularly the vs MAP
columns. Be sure that the MAP at which you are
seeing KR (on my car, seems like it's the few cells
where the throttle is moving from ~20% to 100%
but has not gotten there, that are the initiators)
has a fairly fat multiplier. Look at the FAM PID in
your logs; is it 1.000 when you pop KR? If so, how
can you get earlier enrichment to come in?
This is a nagging question in my mind - what are
the trigger conditions for open loop and for PE?
Have yet to find the logic described.
you
09-12-2004, 01:00 PM
#25
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
Originally Posted by TT_Vert
one thing, i dont think im in open loop on these transients as im not really on the gas (Alook at TPS), am i really in open loop?
Dave
Dave
is closed loop).
The $128 question is, how the hell do you get enrichment to
happen when you need it?
09-12-2004, 08:46 PM
#26
TECH Fanatic
Thread Starter
iTrader: (12)
Join Date: May 2004
Location: Elgin, Illinois
Posts: 1,080
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by jimmyblue
Another thing - look at the profile of the open loop
fuel air vs MAP vs ECT table, particularly the vs MAP
columns. Be sure that the MAP at which you are
seeing KR (on my car, seems like it's the few cells
where the throttle is moving from ~20% to 100%
but has not gotten there, that are the initiators)
has a fairly fat multiplier. Look at the FAM PID in
your logs; is it 1.000 when you pop KR? If so, how
can you get earlier enrichment to come in?
This is a nagging question in my mind - what are
the trigger conditions for open loop and for PE?
Have yet to find the logic described.
you
Last edited by TT_Vert; 09-12-2004 at 08:52 PM.
09-13-2004, 08:43 AM
#27
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
What I meant is, the Fuel Air Multiplier PID - in closed
loop is -has- to be 1.0 and if it is not, then you are
open loop and using the value from {OLFA, PE, ???}.
If these tables had 1.000 values in them you might
not know that happened, but a non-1.000 value
means you are open loop.
There's nothing wrong per se with having 1.000 values
at the lower-MAP end of the OLFA table, though you
could change them to 1.001 just to make them stand
out in the logger.
loop is -has- to be 1.0 and if it is not, then you are
open loop and using the value from {OLFA, PE, ???}.
If these tables had 1.000 values in them you might
not know that happened, but a non-1.000 value
means you are open loop.
There's nothing wrong per se with having 1.000 values
at the lower-MAP end of the OLFA table, though you
could change them to 1.001 just to make them stand
out in the logger.
02-12-2005, 05:43 AM
#29
On The Tree
iTrader: (3)
Join Date: Jul 2003
Location: Indianapolis
Posts: 170
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by etperformance
By the way, I think if you haven't, you should knock
the attack rate down to something like 0.1 - 0.05 and
up the decay rate to 0.2 - 0.3; this will really reduce
the harsh jump-up (who needs 4 degrees on the first
ping?) and make it go away a lot quicker. If there is a
persistent ping it will still "motorboat" along at the
roughly-right pullback, just take another tenth of a
second to get there.
Are you speaking of the attack rate vs. RPM??
Also up your burst knock threshold to something like
0.05 and you should not see BK except on throttle
transients; 0.01 delta CylAir may let it trigger on
simple acceleration airflow run-up, 0.02 was enough
for a mild-mods truck, play with the trigger value
if you see a lot or KR in first, less in second and none
in third. Also I pulled back my whole BK/RPM table to
2.00; if you suspect BK as part of your KR readings
you could "tag" it like by setting the table to 2.222
or something unique and seeing if that just happens
to be what you get for KR.
Is this the Burst KR vs RPM, or Delta?
the attack rate down to something like 0.1 - 0.05 and
up the decay rate to 0.2 - 0.3; this will really reduce
the harsh jump-up (who needs 4 degrees on the first
ping?) and make it go away a lot quicker. If there is a
persistent ping it will still "motorboat" along at the
roughly-right pullback, just take another tenth of a
second to get there.
Are you speaking of the attack rate vs. RPM??
Also up your burst knock threshold to something like
0.05 and you should not see BK except on throttle
transients; 0.01 delta CylAir may let it trigger on
simple acceleration airflow run-up, 0.02 was enough
for a mild-mods truck, play with the trigger value
if you see a lot or KR in first, less in second and none
in third. Also I pulled back my whole BK/RPM table to
2.00; if you suspect BK as part of your KR readings
you could "tag" it like by setting the table to 2.222
or something unique and seeing if that just happens
to be what you get for KR.
Is this the Burst KR vs RPM, or Delta?
Also, my recovery table (recovery rate vs RPM) have values in the 0.015 range. Do you mean up them to 0.02 or 0.2? I don't want to be off by a factor of ten.
02-13-2005, 02:00 AM
#30
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
I think this indicates that you are still closed loop and
not enriched, at least momentarily, high cylinder pressure
and stoich will ping. You might want to lower your PE
enable threshold, to below the MAP seen at start-of-ping
if you think your spark advance is not excessive.
not enriched, at least momentarily, high cylinder pressure
and stoich will ping. You might want to lower your PE
enable threshold, to below the MAP seen at start-of-ping
if you think your spark advance is not excessive.
02-13-2005, 04:19 AM
#31
On The Tree
iTrader: (3)
Join Date: Jul 2003
Location: Indianapolis
Posts: 170
Likes: 0
Received 0 Likes
on
0 Posts
jimmyblue, would you mind taking a stab at my post just above yours? i'm a little confused and definitely would like to 'tone-down' the excessive KR I get, so i can focus on my timing.
02-13-2005, 10:22 AM
#32
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,604
Likes: 0
Received 6 Likes
on
6 Posts
HPTuners changed the "display basis" of the fast attack
param. I haven't gone back to it since then (no need).
Here is what my stock '02 SS had, and has now. You
should consider these only indicaion, not prescription;
how much your motor needs saving, etc. factors into
it. If I were running nitrous or pushing the edge of
boost etc. I would make KR a lot more authoritative
and quick to act. But for purposes of tuning it is
helpful to keep KR from obscuring the ping activity,
and these settings are what I run around with (a
relatively low-mods car engine-wise, that only gets
fed brand-name premium).
Basically, attack rate down and recovery rate up,
to the point that you are happy with the performance
/ protection / observability tradeoff.
KR Fast Attack Gain vs ECT
KR fast attack rate vs rpm
Stock
24 26 26 26 26 26 26 28 32 34 36 38 44 44 44 44 44 44 44 44 44
My Current
9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011
KR recovery rate vs RPM
Stock
0.015 0.015 0.015 0.015 0.015 0.015 0.016 0.016 0.016 0.016 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013
My Current
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
param. I haven't gone back to it since then (no need).
Here is what my stock '02 SS had, and has now. You
should consider these only indicaion, not prescription;
how much your motor needs saving, etc. factors into
it. If I were running nitrous or pushing the edge of
boost etc. I would make KR a lot more authoritative
and quick to act. But for purposes of tuning it is
helpful to keep KR from obscuring the ping activity,
and these settings are what I run around with (a
relatively low-mods car engine-wise, that only gets
fed brand-name premium).
Basically, attack rate down and recovery rate up,
to the point that you are happy with the performance
/ protection / observability tradeoff.
KR Fast Attack Gain vs ECT
KR fast attack rate vs rpm
Stock
24 26 26 26 26 26 26 28 32 34 36 38 44 44 44 44 44 44 44 44 44
My Current
9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011 9.011
KR recovery rate vs RPM
Stock
0.015 0.015 0.015 0.015 0.015 0.015 0.016 0.016 0.016 0.016 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013 0.013
My Current
0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25
02-14-2005, 06:50 PM
#33
On The Tree
iTrader: (3)
Join Date: Jul 2003
Location: Indianapolis
Posts: 170
Likes: 0
Received 0 Likes
on
0 Posts
Awesome, thanks jimmyblue. I'm running a stock internal LS1 with I/E/LT Headers.
I think it sounds like I can just use your numbers with my current mods, but would you mind spelling out what brought you to those particular numbers? I know you want to make the KR less intrusive, but why .25 and not .1 for example? I know that's a kinda tricky question, but I get the gist you aren't the type who does much without good rationale to back it up.
I think it sounds like I can just use your numbers with my current mods, but would you mind spelling out what brought you to those particular numbers? I know you want to make the KR less intrusive, but why .25 and not .1 for example? I know that's a kinda tricky question, but I get the gist you aren't the type who does much without good rationale to back it up.
