VE tuning, what rpms and throttle %
VE tuning, what rpms and throttle % Ok, I did my first round of VE table tuning.
Unplugged MAF, set low octane spark to high octane spark values. Drove for 20 min and logged.
But, I never exceeded 4000rpm, and I didn't exceed 50% throttle.
Is that correct? Nothing I've read has really specified.
I do plan on keeping my MAF.
Should I do some full throttle runs, or 75% for UNDER 4000rpm, or do some part throttle above 4000 rpm?
Or, should I just leave those cells alone in my VE table?
Unplugged MAF, set low octane spark to high octane spark values. Drove for 20 min and logged.
But, I never exceeded 4000rpm, and I didn't exceed 50% throttle.
Is that correct? Nothing I've read has really specified.
I do plan on keeping my MAF.
Should I do some full throttle runs, or 75% for UNDER 4000rpm, or do some part throttle above 4000 rpm?
Or, should I just leave those cells alone in my VE table?
Interesting thing I noticed while logging- The car didn't seem to drive any different with the MAF unplugged.
I haven't touched the VE table other than in the idle rpm ranges.
When I orignally tuned the car for LTFT and STFT, I scaled the IFR table (back in 2004, that's what everyone said to do). So this is my first attempt at VE.
I haven't touched the VE table other than in the idle rpm ranges.
When I orignally tuned the car for LTFT and STFT, I scaled the IFR table (back in 2004, that's what everyone said to do). So this is my first attempt at VE.
VE is used under 4000RPM's. If you disable PE mode you can go through all throttle positions while staying in closed loop. If you do this you can hit all of the cells that you need to to get a good VE table tune. If you dont disable PE and go WOT you will just go into open loop. You still do want to tune VE even if you are keeping the MAF they work together.
Originally Posted by silverTA2002
Interesting thing I noticed while logging- The car didn't seem to drive any different with the MAF unplugged.
I haven't touched the VE table other than in the idle rpm ranges.
When I orignally tuned the car for LTFT and STFT, I scaled the IFR table (back in 2004, that's what everyone said to do). So this is my first attempt at VE.
I haven't touched the VE table other than in the idle rpm ranges.
When I orignally tuned the car for LTFT and STFT, I scaled the IFR table (back in 2004, that's what everyone said to do). So this is my first attempt at VE.
Originally Posted by brad8266
It wont, my logs were better woth MAF unplugged until I got the MAF dialed in. You should not mess with IFR unless you changed injectors.
Is this going to matter? Should I go back to stock?
This was two years ago, and I've done TONS of tuning since then. I don't want to have to start over.
Originally Posted by brad8266
VE is used under 4000RPM's. If you disable PE mode you can go through all throttle positions while staying in closed loop. If you do this you can hit all of the cells that you need to to get a good VE table tune. If you dont disable PE and go WOT you will just go into open loop. You still do want to tune VE even if you are keeping the MAF they work together.
When tuning below 4000 rpm, should I just focus on part throttle and cruise, or all throttle positions?
Should I disable PE and tune above 4000 if I'm keeping my MAF?
Something I noticed from my log was that in higher thottle positions (50%)and higher rpms (around 4k) the LTFTs were all around -2.
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If you have pe off you want to hit as many cells as possable as much as you can all loads and rpm ranges even if you keeping maf the car still needs to know how effecient it is. Also i would change the ifr back to stock I know it sucks but its better to do it with the right callibration so if you get bigger injectors every thing isnt messed up.
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Change your IFR table back to stock and/or calculate it using this: http://www.allmod.net/hpt/injectors.xls
You're using a wideband O2 sensor, right...?
When logging during VE tuning mode, try to hit higher rpms a few times
(e.g. let 1st gear spin to 6000 RPM, let 2nd spin as high as you're willing to go);
you'll find that you'll hit only about 60% (or less) of the cells in the VE table,
this is okay because this is your "driving range";
get you VE table dialed in first, then use the same WB error correction multiplier on the MAF table (re-enable the MAF) using a histogram shaped to the MAF table dimensions.
Important: follow ALL the instructions you have in setting up the tune for VE tuning mode
(i.e. in setting the OLFA table, disabling MAF, DFCO, COT, etc, etc).
You're using a wideband O2 sensor, right...?
When logging during VE tuning mode, try to hit higher rpms a few times
(e.g. let 1st gear spin to 6000 RPM, let 2nd spin as high as you're willing to go);
you'll find that you'll hit only about 60% (or less) of the cells in the VE table,
this is okay because this is your "driving range";
get you VE table dialed in first, then use the same WB error correction multiplier on the MAF table (re-enable the MAF) using a histogram shaped to the MAF table dimensions.
Important: follow ALL the instructions you have in setting up the tune for VE tuning mode
(i.e. in setting the OLFA table, disabling MAF, DFCO, COT, etc, etc).
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Originally Posted by joecar
Change your IFR table back to stock and/or calculate it using this: http://www.allmod.net/hpt/injectors.xls
You're using a wideband O2 sensor, right...?
When logging during VE tuning mode, try to hit higher rpms a few times
(e.g. let 1st gear spin to 6000 RPM, let 2nd spin as high as you're willing to go);
you'll find that you'll hit only about 60% (or less) of the cells in the VE table,
this is okay because this is your "driving range";
get you VE table dialed in first, then use the same WB error correction multiplier on the MAF table (re-enable the MAF) using a histogram shaped to the MAF table dimensions.
Important: follow ALL the instructions you have in setting up the tune for VE tuning mode
(i.e. in setting the OLFA table, disabling MAF, DFCO, COT, etc, etc).
You're using a wideband O2 sensor, right...?
When logging during VE tuning mode, try to hit higher rpms a few times
(e.g. let 1st gear spin to 6000 RPM, let 2nd spin as high as you're willing to go);
you'll find that you'll hit only about 60% (or less) of the cells in the VE table,
this is okay because this is your "driving range";
get you VE table dialed in first, then use the same WB error correction multiplier on the MAF table (re-enable the MAF) using a histogram shaped to the MAF table dimensions.
Important: follow ALL the instructions you have in setting up the tune for VE tuning mode
(i.e. in setting the OLFA table, disabling MAF, DFCO, COT, etc, etc).
The instructions I'm using say this:
To simulate this MAF failure, we will do the following:
1.) Disconnect the MAF from the engine’s wiring harness.
2.) Using HPTuner, copy the High Octane Spark Table to the Low Octane Spark Table.
3.) Flash the PCM.
4.) Start the vehicle, and using the scanner reset your LTFT’s.
5.) Viola! You are now running in SD mode!
From: https://ls1tech.com/forums/attachmen...chmentid=29756
OFLA, DFCO
Also, when logging, should the A/C be On or OFF, or doesn't it matter?
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I dont think it would affect fuel trims that much with ac on or off but i would do both and see if there is a differance i honestly dont know i have never used my ac. Also sae or metric dosent matter for fuel trims they are set buy the computer to tell you how many "steps" rich or lean it has moved to correct the air fuel ratio.
If you are tuning via fuel trims you don't need to touch the OLFA table. DFCO (deceleration fuel cut off) should be disabled so as not to mess with your off throttle fuel trims. I tuned my ve table using fuel trims for a few months before getting a wideband (highly recommended, much easier). I did not disable pe, and would not recommend it. It is easier (and safer) to just set up a custom filter in your LTFT / STFT histogram to only record fuel trims at stoich (14.63 commanded afr or fuel air mult = 1.00).
Ok, and when do I plug the MAF back in? After I'm completely done tuning, relearning LTFTs, recalibrate MAF?
Or, should I plug it back in while driving to relearn trims?
Or, should I plug it back in while driving to relearn trims?
After you've got your trims down to -4 to 0 in SD, then you can re-enable the MAF and use the fuel trims again this time to alter the MAF table. Remember the purpose of going SD to tune the VE table is to eliminate the MAF from contributing to fuel trimming. If you are still tuning the VE table and you are driving around to let the LTFTs settle, you do not want the MAF enabled. Hope this helps. 
Originally Posted by bshell
After you've got your trims down to -4 to 0 in SD, then you can re-enable the MAF and use the fuel trims again this time to alter the MAF table. Remember the purpose of going SD to tune the VE table is to eliminate the MAF from contributing to fuel trimming. If you are still tuning the VE table and you are driving around to let the LTFTs settle, you do not want the MAF enabled. Hope this helps.
Ok, now I'm a bit confused.
I'm on my third LTFT log (after driving for an hour since last VE change).
I have a couple of problems.
1. I've reduced my VE table by about 12 spaces in most low rpm areas so far. BUT, my average LTFTs are still the same in those spaces. About -7. (1200-1600rpm). Everything else is about 1 or 2.
2. There's about an 8% difference between bank 1 and 2. Bank 2 is negative about 8% more than bank 1. Bank 2 keeps settling on -14.8% when I let off the gas. That exact number for ALL the logs.
I checked for exhaust leaks and haven't found any.
Looking at the table view, my Bank 1 is positive, and my bank 2 is negative for LTFTs. GRRR.
I'm on my third LTFT log (after driving for an hour since last VE change).
I have a couple of problems.
1. I've reduced my VE table by about 12 spaces in most low rpm areas so far. BUT, my average LTFTs are still the same in those spaces. About -7. (1200-1600rpm). Everything else is about 1 or 2.
2. There's about an 8% difference between bank 1 and 2. Bank 2 is negative about 8% more than bank 1. Bank 2 keeps settling on -14.8% when I let off the gas. That exact number for ALL the logs.
I checked for exhaust leaks and haven't found any.
Looking at the table view, my Bank 1 is positive, and my bank 2 is negative for LTFTs. GRRR.