Speed Density 2.0 (3D VE Tables, Baro)
Okk, figured it out. For some reason the mapv:KPA scaling got screwed up even though I was still listed as an omni 4 bar. Then I went to copy the map v to kpa column to make it 1:1 and it reverted the map back to kpaomni3bar. I didnt catch that it flipped the scaling down by making it 1:1. So I had to change the scaling to 4bar, then make it 1:1. I dont quite get why it made these changes automatically or what, but I think I got it sorted now. Just seemed really odd since Ive been runing the same rom for a little over a month now.
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From: singaproe
When you used this approach, what did you set your MAF Comp table to? Was it set to 100 across all MAF Hz?
No, I am finally learning how to adjust the MAF comp table. Until last week I never scaled my injectors and dealt with funky fuel trims. Finally I was on a kick to learn something...
So I made my fuel map to what i desired for AFR in the past and just adjusted VE to get my desired... recently I had to adjust VE to lower the Hz at idle slightly(Closed loop), and use MAF comp to the scaling to get the trims reasonable.
johnbradley pointed out that you need to adjust VE according to your STFT in closed loop. So that was[am currently] how I tackled it and if you see the STFT - you need to take VE out and if its + you need to add fuel at that MAP/RPM. I have been trying to disable LTFT so that I can drive and not have LTFT interfere while adjusting the VE to get the CL portion working right.
I still may infact be doing it wrong.
Jamie @ Dynotech has pointed out a very useful way to use your MAF sensor to create a 3d VE map for you. Funny thing is, thats so easy everyone over looks it! So I dont have a MAF sensor right now that I can use for this, because mine is gutted and my exhaust has a few leaks that I need to wrap up. But if you venture in one of the two threads that I just started below you will see his post which ... will eventually be the way which i will try.
My current plan of attack is just get things close enough to give my ANTI-LAG solution a try using factory components then based on the sucess or failure of that, continue to refine my SD tune by using a MAF or maybe not.
So I made my fuel map to what i desired for AFR in the past and just adjusted VE to get my desired... recently I had to adjust VE to lower the Hz at idle slightly(Closed loop), and use MAF comp to the scaling to get the trims reasonable.
johnbradley pointed out that you need to adjust VE according to your STFT in closed loop. So that was[am currently] how I tackled it and if you see the STFT - you need to take VE out and if its + you need to add fuel at that MAP/RPM. I have been trying to disable LTFT so that I can drive and not have LTFT interfere while adjusting the VE to get the CL portion working right.
I still may infact be doing it wrong.
Jamie @ Dynotech has pointed out a very useful way to use your MAF sensor to create a 3d VE map for you. Funny thing is, thats so easy everyone over looks it! So I dont have a MAF sensor right now that I can use for this, because mine is gutted and my exhaust has a few leaks that I need to wrap up. But if you venture in one of the two threads that I just started below you will see his post which ... will eventually be the way which i will try.
My current plan of attack is just get things close enough to give my ANTI-LAG solution a try using factory components then based on the sucess or failure of that, continue to refine my SD tune by using a MAF or maybe not.
I would buy another or borrow one for a day.
Here is a simple way of explaining VE (there is more to it than this really). 100% VE means, at 100kpa with 100%VE, the engine assumes that 100KPA=100load. This means that the cylinders COMPLETELY suck in & push out their total volume of air and the ECU sends enough fuel to match. Due to turbulance and poor airflow at certain RPM and engine loads, 100% VE isn't always the case.
Lets use idle as an example. Most cars will idle at 40-65kpa. Lets use a stock Evo that pulls around -18 to -19inHG at idle (around 40KPA) and the maf reading shows a load of 30.
VE can be calculated by using this formula:
LOAD/KPA*100
30/40*100= 75% VE
This means at that particular KPA and RPM the cylinders are only sucking in/pushing out roughly 75% of their capacity and the ECU should only give 75% of the fuel to match.
Now lets use a big cam that has less vacuum. With the MAF installed, you may see -12inHG of vacuum at idle (about 60kpa) and a MAF calculated load of 33.
LOAD/KPA*100=VE
30/60*100= 50% VE
You can log VE in evoscan by using a formula similar to the one below while using your MAF:
([load1B]/[JDMMAPkpa])*100
After logging, you can use your averages in each KPA/RPM area to determine the MAF calculated VE. The more data you get for each cell, the more accurate your VE table will be.
Most evos I have seen have a VE of roughly 80% in the 2000-3000rpm/40-80KPA range for average highway cruising.
-Jamie
Here is a simple way of explaining VE (there is more to it than this really). 100% VE means, at 100kpa with 100%VE, the engine assumes that 100KPA=100load. This means that the cylinders COMPLETELY suck in & push out their total volume of air and the ECU sends enough fuel to match. Due to turbulance and poor airflow at certain RPM and engine loads, 100% VE isn't always the case.
Lets use idle as an example. Most cars will idle at 40-65kpa. Lets use a stock Evo that pulls around -18 to -19inHG at idle (around 40KPA) and the maf reading shows a load of 30.
VE can be calculated by using this formula:
LOAD/KPA*100
30/40*100= 75% VE
This means at that particular KPA and RPM the cylinders are only sucking in/pushing out roughly 75% of their capacity and the ECU should only give 75% of the fuel to match.
Now lets use a big cam that has less vacuum. With the MAF installed, you may see -12inHG of vacuum at idle (about 60kpa) and a MAF calculated load of 33.
LOAD/KPA*100=VE
30/60*100= 50% VE
You can log VE in evoscan by using a formula similar to the one below while using your MAF:
([load1B]/[JDMMAPkpa])*100
After logging, you can use your averages in each KPA/RPM area to determine the MAF calculated VE. The more data you get for each cell, the more accurate your VE table will be.
Most evos I have seen have a VE of roughly 80% in the 2000-3000rpm/40-80KPA range for average highway cruising.
-Jamie
Last edited by 211Ratsbud; Dec 23, 2012 at 12:57 PM.
I'm transitioning from a fully developed MAF tune to 3D SD. This means that my AFR, boost, timing, injector size and latency, MAF Size and Comp are all perfect for my current build. Most of the past two months in fact was spent tuning MAF Comp from idle to cruise, to get STFT under control. Let me know if I can help you here.
I have good MAF load vs kPa data from evoscan so I can set the starting point for 3D VE. There are a few of important questions that I have not found answers to:
1. Should kPa2Load be left at 1:1 if using a 3D VE map built from my MAF tune? (I would have thought that this could keep AFRs too lean and timing too advanced at full boost, since my actual load (310) exceeds kPa (280). )
2. Should MAF Scaling and MAF Compensation tables be copied over from to 3D SD tune?
3. Should kPa2Load be set based on data from MAF tune (see below for my setup - big cams)?
I have good MAF load vs kPa data from evoscan so I can set the starting point for 3D VE. There are a few of important questions that I have not found answers to:
1. Should kPa2Load be left at 1:1 if using a 3D VE map built from my MAF tune? (I would have thought that this could keep AFRs too lean and timing too advanced at full boost, since my actual load (310) exceeds kPa (280). )
2. Should MAF Scaling and MAF Compensation tables be copied over from to 3D SD tune?
3. Should kPa2Load be set based on data from MAF tune (see below for my setup - big cams)?
Yes, with a 3D table, the kpa2load should be 1:1 with the proper map sensor scaling selected. MAF scaling and comp should be copied over.
The VE table should be adjusted based on the MAF data first. The kpa2load table is just used to tweak certain KPA areas.
-Jamie
The VE table should be adjusted based on the MAF data first. The kpa2load table is just used to tweak certain KPA areas.
-Jamie
Last edited by Dynotech Tuning; Dec 23, 2012 at 02:37 PM.
I'm transitioning from a fully developed MAF tune to 3D SD. This means that my AFR, boost, timing, injector size and latency, MAF Size and Comp are all perfect for my current build. Most of the past two months in fact was spent tuning MAF Comp from idle to cruise, to get STFT under control. Let me know if I can help you here.
I have good MAF load vs kPa data from evoscan so I can set the starting point for 3D VE. There are a few of important questions that I have not found answers to:
1. Should kPa2Load be left at 1:1 if using a 3D VE map built from my MAF tune? (I would have thought that this could keep AFRs too lean and timing too advanced at full boost, since my actual load (310) exceeds kPa (280). )
2. Should MAF Scaling and MAF Compensation tables be copied over from to 3D SD tune?
3. Should kPa2Load be set based on data from MAF tune (see below for my setup - big cams)?
I have good MAF load vs kPa data from evoscan so I can set the starting point for 3D VE. There are a few of important questions that I have not found answers to:
1. Should kPa2Load be left at 1:1 if using a 3D VE map built from my MAF tune? (I would have thought that this could keep AFRs too lean and timing too advanced at full boost, since my actual load (310) exceeds kPa (280). )
2. Should MAF Scaling and MAF Compensation tables be copied over from to 3D SD tune?
3. Should kPa2Load be set based on data from MAF tune (see below for my setup - big cams)?
Good point the kpa to load should be used to line up your load points after you copy your maf tables over then use ve merely to tweak the fuel is how I comprehend it.
Yes, with a 3D table, the kpa2load should be 1:1 with the proper map sensor scaling selected. MAF scaling and comp should be copied over.
The VE table should be adjusted based on the MAF data first. The kpa2load table is just used to tweak certain KPA areas.
-Jamie
The VE table should be adjusted based on the MAF data first. The kpa2load table is just used to tweak certain KPA areas.
-Jamie
No that is way to Quixotic a project for me 
.
AFRMAP is just a number to be dialled up or down to set actual AFR where I want it in open loop boost. In closed loop idle or cruise I have used MAF Comp to get mid and low trims in line. I did this by logging MAF Hz and AFR%Error = ([WBO2]-[AFRMAP])*100/[AFRMAP], then adding or subtracting the AFR%Error to MAF Comp at the correct Hz band.
If you are doing this from scratch it's probably easier to use ziad's LiveMap version with autotune to get AFR's tuned quickly.
.AFRMAP is just a number to be dialled up or down to set actual AFR where I want it in open loop boost. In closed loop idle or cruise I have used MAF Comp to get mid and low trims in line. I did this by logging MAF Hz and AFR%Error = ([WBO2]-[AFRMAP])*100/[AFRMAP], then adding or subtracting the AFR%Error to MAF Comp at the correct Hz band.
If you are doing this from scratch it's probably easier to use ziad's LiveMap version with autotune to get AFR's tuned quickly.
I'm working on getting a 1.3 cable to live map. I guess in the end it there is more than one way to accomplish this goal. I really just want my trims to be excellent.
My midrange ve is around 80 like dyno tech suggested and my low range ve is 68 at idle. I'm going to force open loop above 3500 anyways where my sas will be active to get the alternate map to enrich enough.
I've never seen much more described about sd tuning than what's in the 2d threads as far as maf modeling vs sd. It's nice to see that there is a methodology
Not sure how injector scaling can be accomplished with so many adjustments lol
My midrange ve is around 80 like dyno tech suggested and my low range ve is 68 at idle. I'm going to force open loop above 3500 anyways where my sas will be active to get the alternate map to enrich enough.
I've never seen much more described about sd tuning than what's in the 2d threads as far as maf modeling vs sd. It's nice to see that there is a methodology
Not sure how injector scaling can be accomplished with so many adjustments lol
Last edited by 211Ratsbud; Dec 23, 2012 at 06:06 PM.