Adding PE = No Effect
Thread Starter
Joined: Nov 2001
Posts: 3,066
Likes: 0
From: Sunny San Diego
Originally Posted by TAQuickness
I don't have my software with me to check, but for some reason I *think* I recall seeing a parameter that limits max enrichment. I could be talking out of my *** too.
But ya, it seems like there is a limit at that RPM.
Originally Posted by Ed Blown Vert
Was on the dyno checking AFR. At 4000 it was 12:1 so added 5% to the PE table @ 4000. No change in AFR. Then added another 10% then 15%. Still no change. Everywhere else I had no problem changing the AFR.
What am I missing?
What am I missing?
Also what is the value you have in the ve table at wot above 4k rpms?
You should be able to do some street pulls that show
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
Originally Posted by jimmyblue
You should be able to do some street pulls that show
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Originally Posted by jimmyblue
You should be able to do some street pulls that show
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
Teching In
Joined: Sep 2004
Posts: 19
Likes: 0
Longshot here, but could it be COT?
If COT commands 11.5 and PE commands 12.5, COT will override and the AFR will be 11.5. If you bump PE to 12.0, it will still be 11.5. COT shows up as part of commanded AFR, so you can at least tell.
John.
If COT commands 11.5 and PE commands 12.5, COT will override and the AFR will be 11.5. If you bump PE to 12.0, it will still be 11.5. COT shows up as part of commanded AFR, so you can at least tell.
John.
Thread Starter
Joined: Nov 2001
Posts: 3,066
Likes: 0
From: Sunny San Diego
Originally Posted by jimmyblue
You should be able to do some street pulls that show
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
That must have been when it was using the PE table. I never touched the OLFA table, how does it work??
OLFA is used when the settings call for Open Loop only, like if the CTS is set to over 275 degrees. The ECM will not reference the O2 sensors, nor any other fuel table (less PE). It does not try to run at 14.68572 (or what ever), instead it runs on a graphed multiplier based on that Stoich value. Lower sections of the table (upper left) will sway to a rich condition, towards the right it moves to a leaner condition. You can use this table to fine tune your VE Table for closed loop by setting it to 1.00, also have your PE Table set to where you would like your AFR to be under WOT. Once the VE Table is done, and you enable closed loop, this table will no longer be used. This is how I do it, tune the VE Table via a wideband and the OLFA Table with PE Where I want. 
Power enrichment mode is one of the ways to get
into open loop. Any time you see a commanded
fuel air multiplier <> 1.000 you are open loop. In
open loop the PCM will pick the fattest of the
currently enabled enrichments (PE, OLFA, COT,
whatever).
Anyway, when you meet the conditions to enable
PE, you enter open loop and then pick the chubby
option. If OLFA(MAP,ECT) is greater than the PE(RPM)
then you get the OLFA value.
This really gives you one and one-half degrees of
freedom in tuning WOT. A MAP based enrichment,
and an RPM based one. But the "pick fatter" limits
what you can do, some.
You might find it better to tune as far as possible
with the OLFA table, and then use PE just to tweak
the top end (where the injector table, etc. may fail
to properly model plumbing flow-pressure drop, etc.).
PE gets all the attention but OLFA and the MAP
relation to required enrichment I think is more to
the point.
into open loop. Any time you see a commanded
fuel air multiplier <> 1.000 you are open loop. In
open loop the PCM will pick the fattest of the
currently enabled enrichments (PE, OLFA, COT,
whatever).
Anyway, when you meet the conditions to enable
PE, you enter open loop and then pick the chubby
option. If OLFA(MAP,ECT) is greater than the PE(RPM)
then you get the OLFA value.
This really gives you one and one-half degrees of
freedom in tuning WOT. A MAP based enrichment,
and an RPM based one. But the "pick fatter" limits
what you can do, some.
You might find it better to tune as far as possible
with the OLFA table, and then use PE just to tweak
the top end (where the injector table, etc. may fail
to properly model plumbing flow-pressure drop, etc.).
PE gets all the attention but OLFA and the MAP
relation to required enrichment I think is more to
the point.
No, it's the basic mixture vs MAP table for open
loop. It doesn't have any say about how you get
there, just what happens once you are.
PE mode (MAP, TPS) is the only convenient and
consistent way I know of, to get into open loop
in normal operation. Point is, that once in PE mode
you might prefer to control the fueling on a mostly
MAP basis (OLFA) and use the PE table for RPM-
specific needs.
Or not.
loop. It doesn't have any say about how you get
there, just what happens once you are.
PE mode (MAP, TPS) is the only convenient and
consistent way I know of, to get into open loop
in normal operation. Point is, that once in PE mode
you might prefer to control the fueling on a mostly
MAP basis (OLFA) and use the PE table for RPM-
specific needs.
Or not.
Thread Starter
Joined: Nov 2001
Posts: 3,066
Likes: 0
From: Sunny San Diego
Originally Posted by jimmyblue
You should be able to do some street pulls that show
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
the fuel air multiplier and reference that, to the various
fuel tables (PE, OLFA, COT, adders in play) and see who
is in charge. It might help, if values are the same, to put
a little flag on them (for example instead of everybody
being 1.200, make OLFA be 1.201 and PE be 1.203, etc.).
It might also be interesting to look at the airflow and
CylAir readings as you cross 4000, see if there is any
discontinuity / jump / drop in the value as you run up.
If the SD and MAF are fairly different you might see
something not-smooth at the final transition?
