Programming question
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
Programming question
When looking at the differences between apyp and my bin programmed by another person a while back I noticed a few major differences.
When looking at the Minimum % TPS to enable PE mode I see the stock chip is 70 % where my chip is 30 %. What would the difference be if no changes were made at all in this field?
and
in the apyp under PE vs. RPM I notice a lot of negative values (-7.82) where mine reads anywhere from 60.15 @ 2000 RPM to 6.25 at 6400 rpm. Does this seem normal and/or what would be the major difference in engine performance if no changes were made at all?
Basically I'm trying to understand these changes and why they are made.
When looking at the Minimum % TPS to enable PE mode I see the stock chip is 70 % where my chip is 30 %. What would the difference be if no changes were made at all in this field?
and
in the apyp under PE vs. RPM I notice a lot of negative values (-7.82) where mine reads anywhere from 60.15 @ 2000 RPM to 6.25 at 6400 rpm. Does this seem normal and/or what would be the major difference in engine performance if no changes were made at all?
Basically I'm trying to understand these changes and why they are made.
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
The minimum TPS to enable PE mode makes the car go into its PE mode sooner. PE mode has extra enrichment. Its designed to knock the car from 14.7 type stuff down to 12-13.0 stuff.
It also forgets about most feedback from the o2 sensors.
The PE changes he did he likely did on the dyno. You can change those values to anything to make the desired AFR come out on the dyno. You can't nessisarly guess what the AFR is going to be by those PE numbers.. it is only a desired, which is quite different from actual.
It also forgets about most feedback from the o2 sensors.
The PE changes he did he likely did on the dyno. You can change those values to anything to make the desired AFR come out on the dyno. You can't nessisarly guess what the AFR is going to be by those PE numbers.. it is only a desired, which is quite different from actual.
Pro
Joined: Sep 2001
Posts: 542
Likes: 1
From: Stuck in the 80's
I don't have highway mode spark advance in my definition, but my factory PE spark advance was:
Power Enrichment Mode Spark Advance
RPM Degrees
4800 1.05
3200 9.14
2000 1.05
1200 1.05
400 0.00
When scanning I was getting significant spark retard above 2800 RPM, I adjusted this table down to 1.05 @ 3200 so my PE Spark Advance table is now flat. My factory main spark table is pretty aggressive too, I have taken timing out in some cells there as well to lower my spark retard to only a few degree's instead of the double digits I was getting.
Not sure why OEM settings are the way they are, but I don't see any benefit to be running my timing off the ESC module, which is basically what is happening when the PROM setting is commanding "more timing" and at the same time the ESC module is commanding "take timing away".
Power Enrichment Mode Spark Advance
RPM Degrees
4800 1.05
3200 9.14
2000 1.05
1200 1.05
400 0.00
When scanning I was getting significant spark retard above 2800 RPM, I adjusted this table down to 1.05 @ 3200 so my PE Spark Advance table is now flat. My factory main spark table is pretty aggressive too, I have taken timing out in some cells there as well to lower my spark retard to only a few degree's instead of the double digits I was getting.
Not sure why OEM settings are the way they are, but I don't see any benefit to be running my timing off the ESC module, which is basically what is happening when the PROM setting is commanding "more timing" and at the same time the ESC module is commanding "take timing away".
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by gbody5
Not sure why OEM settings are the way they are, but I don't see any benefit to be running my timing off the ESC module, which is basically what is happening when the PROM setting is commanding "more timing" and at the same time the ESC module is commanding "take timing away".
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
The PROM's spark tables are a "base" for it to work with, adding spark or subtracting it as needed..ie PE mode, knock, coolant temp, etc.
I'd look into why you were getting spark knock at that point. If it was just too much timing, I would adjust the main spark tables , not the PE spark.
I'd look into why you were getting spark knock at that point. If it was just too much timing, I would adjust the main spark tables , not the PE spark.
Pro
Joined: Sep 2001
Posts: 542
Likes: 1
From: Stuck in the 80's
Originally Posted by gbody5
My factory main spark table is pretty aggressive too, I have taken timing out in some cells there as well to lower my spark retard to only a few degree's instead of the double digits I was getting.
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Drifting
Joined: Mar 2005
Posts: 1,923
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From: GA
Still doesn't seem right that you are having to pull so much timing out of the tables. Did the programmer you used alter the tables? Adding more timing?
I'm running the ARAP .bin (about the most agressive timing tables GM made) and have a MAX of 3 knock counts (self test). Hell, I was thinking of adding to the tables, or at least to LV8.
I'm running the ARAP .bin (about the most agressive timing tables GM made) and have a MAX of 3 knock counts (self test). Hell, I was thinking of adding to the tables, or at least to LV8.
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
Don't you guys hate that PE spark adder? 
You can actually see the dip in the spark table where they shoot in 9 degrees in some cars. I just did a car today with 9 degrees at 3200 RPM.. you can see timing rising up to about 2500rpm, a sharp dip, then rising back at 3500 or so..
It makes more since to me to do all the spark in one table.. How often are you going to be at those load values and not be in PE...
Stuiped GM..
Some of the vettes have been able to pick up a little with less timing than the factory puts in them. I think any time you ride the knock sensor your setting yourself up for it to overcorrect.
You can actually see the dip in the spark table where they shoot in 9 degrees in some cars. I just did a car today with 9 degrees at 3200 RPM.. you can see timing rising up to about 2500rpm, a sharp dip, then rising back at 3500 or so.. It makes more since to me to do all the spark in one table.. How often are you going to be at those load values and not be in PE...
Stuiped GM..
Some of the vettes have been able to pick up a little with less timing than the factory puts in them. I think any time you ride the knock sensor your setting yourself up for it to overcorrect.
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Maybe not overcorrect, but the ESC decay rates could really hurt performance by being on the edge of the knock retard...Just a few pings and out comes 11* and it takes its time about letting it back in, unless you want to play with that table too.
Just did a little calculation on my bin, under "normal" conditions I could be running up to 54.2* of timing. I'm going to have to look over some of my scan logs and see if I ever hit that number (or more)
Just did a little calculation on my bin, under "normal" conditions I could be running up to 54.2* of timing. I'm going to have to look over some of my scan logs and see if I ever hit that number (or more)
Last edited by Morley; Aug 9, 2005 at 01:42 AM.
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
I would consider it overcorrecting.. Do you really think your off by 11 degrees in your example..
Also, becareful in what you think the timing is based on what is in the tables. I have verified they are BS with a timing light on the dyno. Same thing with reported advance in a scan tool.. I think the best way to tune SA is on the dyno. You can manipulate timing a different poingts to find the best area under the curve.
Also, becareful in what you think the timing is based on what is in the tables. I have verified they are BS with a timing light on the dyno. Same thing with reported advance in a scan tool.. I think the best way to tune SA is on the dyno. You can manipulate timing a different poingts to find the best area under the curve.
Drifting
Joined: Mar 2005
Posts: 1,923
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From: GA
Originally Posted by Alvin
I would consider it overcorrecting.. Do you really think your off by 11 degrees in your example..
Not to sound crass..but if the timing isn't coming from the tables contained in the .bin, where is it coming from?
I believe that the "reported advance" seen in a scanner is just where it is at on the base map and isn't taking into account the other tables that contribute to the "real" timing that is being run. Then again, like I said, I'm going to have a look at my logs to see where I'm at/when. Never looked at them very hard since I wasn't having a knock problem.
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
We where concerned that we where putting to little timing in a car so we checked the timing with a timing light during a pull. The timing averaged about 10 degrees higher or lower (can't remeber) than what the scan tool reported and what was in the table. My point is don't get hung up on a number. give the car what it likes and thats it.
Pro
Joined: Sep 2001
Posts: 542
Likes: 1
From: Stuck in the 80's
Originally Posted by Morley
Still doesn't seem right that you are having to pull so much timing out of the tables. Did the programmer you used alter the tables? Adding more timing?
I'm running the ARAP .bin (about the most agressive timing tables GM made) and have a MAX of 3 knock counts (self test). Hell, I was thinking of adding to the tables, or at least to LV8.
I'm running the ARAP .bin (about the most agressive timing tables GM made) and have a MAX of 3 knock counts (self test). Hell, I was thinking of adding to the tables, or at least to LV8.
Don't you guys hate that PE spark adder? You can actually see the dip in the spark table where they shoot in 9 degrees in some cars. I just did a car today with 9 degrees at 3200 RPM.. you can see timing rising up to about 2500rpm, a sharp dip, then rising back at 3500 or so..
I also upgraded my ESC module per one of the tech tips, it did help lower my ESC OUT, I posted a comparison a while back.
Instructor
Joined: Aug 2004
Posts: 108
Likes: 0
Originally Posted by Morley
Just did a little calculation on my bin, under "normal" conditions I could be running up to 54.2* of timing. I'm going to have to look over some of my scan logs and see if I ever hit that number (or more)
By the way, I think the scaling in the anht_hac is wrong for this limit. It says 39 deg but that does not appear to be the case if you look at the assembly code. And 39+6 is less than 47.1, not much of a limitation then
Drifting
Joined: Mar 2005
Posts: 1,923
Likes: 0
From: GA
Originally Posted by Blower91
The $8D has a 42 deg limitation (address 8026h) and add 6 deg initial timing and you arrive at 48 deg. Max SA in my logs are 47.1. Parhaps you don't run the $8D code? What is your max then?
By the way, I think the scaling in the anht_hac is wrong for this limit. It says 39 deg but that does not appear to be the case if you look at the assembly code. And 39+6 is less than 47.1, not much of a limitation then
By the way, I think the scaling in the anht_hac is wrong for this limit. It says 39 deg but that does not appear to be the case if you look at the assembly code. And 39+6 is less than 47.1, not much of a limitation then
