Illustrated SD nub questions
Thread Starter
Evolving Member
Joined: Jul 2009
Posts: 274
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From: MA
Illustrated SD nub questions
Hello all, I'm actually not a nub to SD... Or at least I shouldn't be as I have been using it and trying to tune it since JCBanks's patch and V6T. However, the fundamental concepts of how to tune it are still hazy to me even though I have read all of the threads to date explaining it. I am still relatively new to "tuning" in general (only since ecuflash became availble a couple years ago, but no DSMs or other EFI experience).
I need visual aids and specific insight into what the values I have been staring at for a year or so now mean.
My set-up is pretty stockish so I have "tuned" the car purely by keeping the stock fuel maps as is and tweaking the SD tables and injector scaling up or down a little until the wideband AFR is safe and close to the map AFR and the trims are under +/- 5, most importantly the car "feels" good.
Now, it runs and drives well but certain situations like high load, low RPM I have no concept of how to address. JB and others have have tried to explain it but with no refferences I'm understanding, or visual aides I'm still lost
. If you guys can help hammer some of these concepts through my head I can inturn create some visual support (in addition to the existing how to write-ups that lost me).
I really want to build a visual of this 3D graph that everyone keeps talking about and super-impose a "roadmap" (like the ones we have for AFR and timing) showing idle, cruise, high load+ low RPM, WOT areas, etc. But I need some really basic help first. It's unfortunately just the way my brain works... or doesn't work depending on how you look at it. Good news is I'm really good at photoshop and illustrator.
I numbered 7 questions, shout em out if you know the answers! Thanks.
I need visual aids and specific insight into what the values I have been staring at for a year or so now mean.
My set-up is pretty stockish so I have "tuned" the car purely by keeping the stock fuel maps as is and tweaking the SD tables and injector scaling up or down a little until the wideband AFR is safe and close to the map AFR and the trims are under +/- 5, most importantly the car "feels" good.
Now, it runs and drives well but certain situations like high load, low RPM I have no concept of how to address. JB and others have have tried to explain it but with no refferences I'm understanding, or visual aides I'm still lost
. If you guys can help hammer some of these concepts through my head I can inturn create some visual support (in addition to the existing how to write-ups that lost me).I really want to build a visual of this 3D graph that everyone keeps talking about and super-impose a "roadmap" (like the ones we have for AFR and timing) showing idle, cruise, high load+ low RPM, WOT areas, etc. But I need some really basic help first. It's unfortunately just the way my brain works... or doesn't work depending on how you look at it. Good news is I'm really good at photoshop and illustrator.
I numbered 7 questions, shout em out if you know the answers! Thanks.
1. Yes
2. It should be closest to baro+temp compensated load, but some people have stated that their fuel matches 1 byte load.
3. No, leaner AFR. These are VE tables. The map VE table can be viewed as a percentage (like the RPM VE table) by dividing the right column by the left column. The higher the right column, you are stating you have a higher VE.
4. 1:1 means that you are stating you are 100% map VE at that map level. So, you are basically getting no adjustment for VE at that map and will only use the RPM VE adjustment. Total VE is map ve * rpm ve. This is how the SD patch works and how your fueling is calculated.
5. Since there are two VE tables, it's hard to answer this question. It matters what your car's VE is at a certain map and RPM. The two 2D tables should reflect that to get an accurate 3D VE table. The last colum in your map VE table should be the highest map that your map sensor can read.
6. If I have time later, I might make a post explaining how to get a 3D table out of these two tables. It will show the inherent flaws using two 2D tables rather than a big 3D table.
7. The best way is to simply log your car to see the fuel corrections. If you are already on SD, that would be with selected LTFT + STFT. If you aren't on SD yet, then you can get maf logs and make 3D VE tables as have been explained in John's threads.
8. That value represents your RPM VE pecentage. 80 means 80% VE. It gets multiplied by the percent of map VE (for the map level you are at) and then the fueling gets calculated from there.
2. It should be closest to baro+temp compensated load, but some people have stated that their fuel matches 1 byte load.
3. No, leaner AFR. These are VE tables. The map VE table can be viewed as a percentage (like the RPM VE table) by dividing the right column by the left column. The higher the right column, you are stating you have a higher VE.
4. 1:1 means that you are stating you are 100% map VE at that map level. So, you are basically getting no adjustment for VE at that map and will only use the RPM VE adjustment. Total VE is map ve * rpm ve. This is how the SD patch works and how your fueling is calculated.
5. Since there are two VE tables, it's hard to answer this question. It matters what your car's VE is at a certain map and RPM. The two 2D tables should reflect that to get an accurate 3D VE table. The last colum in your map VE table should be the highest map that your map sensor can read.
6. If I have time later, I might make a post explaining how to get a 3D table out of these two tables. It will show the inherent flaws using two 2D tables rather than a big 3D table.
7. The best way is to simply log your car to see the fuel corrections. If you are already on SD, that would be with selected LTFT + STFT. If you aren't on SD yet, then you can get maf logs and make 3D VE tables as have been explained in John's threads.
8. That value represents your RPM VE pecentage. 80 means 80% VE. It gets multiplied by the percent of map VE (for the map level you are at) and then the fueling gets calculated from there.
Thread Starter
Evolving Member
Joined: Jul 2009
Posts: 274
Likes: 0
From: MA
Hey thanks for the answers, I didn't have much time to work on this today but I got to work on #1 and 2. I will get through all of them in time
Just to get a frame of refference with familiar values in the MAP/VE table I converted the numbers I had in my KPa column to PSI and then from logs, found the corresponding 1byte loads at those pressures to fill the right hand column. I realize this is ball park but still helped me understand what I'm looking at and generates some more questions:
1. How come there is no negative KPa values for vacuum/ no load under 100 in the MAP/VE table?
2. Where does the scale come from for the KPa column, when I selected MAP16/ JDM3bar it just filled those in, however the last cell is 40.6 PSI, is this minus atmospheric pressure (26.6PSIa)?
3. From the same log I can refference the RPM I saw those values at (pressure+load) and begin to build a 3d chart plot?
Just to get a frame of refference with familiar values in the MAP/VE table I converted the numbers I had in my KPa column to PSI and then from logs, found the corresponding 1byte loads at those pressures to fill the right hand column. I realize this is ball park but still helped me understand what I'm looking at and generates some more questions:
1. How come there is no negative KPa values for vacuum/ no load under 100 in the MAP/VE table?
2. Where does the scale come from for the KPa column, when I selected MAP16/ JDM3bar it just filled those in, however the last cell is 40.6 PSI, is this minus atmospheric pressure (26.6PSIa)?
3. From the same log I can refference the RPM I saw those values at (pressure+load) and begin to build a 3d chart plot?
Last edited by 95630706; Jul 9, 2010 at 01:55 PM.
Hey thanks for the answers, I didn't have much time to work on this today but I got to work on #1 and 2. I will get through all of them in time
Just to get a frame of refference with familiar values in the MAP/VE table I converted the numbers I had in my KPa column to PSI and then from logs, found the corresponding 1byte loads at those pressures to fill the right hand column. I realize this is ball park but still helped me understand what I'm looking at and generates some more questions:
1. How come there is no negative KPa values for vacuum/ no load under 100 in the MAP/VE table?
2. Where does the scale come from for the KPa column, when I selected MAP16/ JDM3bar it just filled those in, however the last cell is 40.6 PSI, is this minus atmospheric pressure (26.6PSIa)?
3. From the same log I can refference the RPM I saw those values at (pressure+load) and begin to build a 3d chart plot?
Just to get a frame of refference with familiar values in the MAP/VE table I converted the numbers I had in my KPa column to PSI and then from logs, found the corresponding 1byte loads at those pressures to fill the right hand column. I realize this is ball park but still helped me understand what I'm looking at and generates some more questions:
1. How come there is no negative KPa values for vacuum/ no load under 100 in the MAP/VE table?
2. Where does the scale come from for the KPa column, when I selected MAP16/ JDM3bar it just filled those in, however the last cell is 40.6 PSI, is this minus atmospheric pressure (26.6PSIa)?
3. From the same log I can refference the RPM I saw those values at (pressure+load) and begin to build a 3d chart plot?
2. The scale comes from whatever map sensor you are using. As mentioned in #1, this is absolute pressure (+14.7 psi at sea level).
3. Your 3D chart should be a 3D VE chart if you are logging from a maf prior to going to SD. If you are already on SD, it would be good to simply make a 3D fuel correction chart (selected LTFT + STFT) to see where your VE needs to be adjusted up or down.
