VE/SD Tune on 3800
- Thread starter PANDA
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VE and maf are the primary tables.....the riv ran fine on the maf and VE table it drove there on....after more than a few light/med/high load (FT cell) VE tunes it wouldnt even idle with the maf.
based on my work with MS and accel/big stuff, the MAF is the load rationality check, actual pumping efficiency is the primary table, in our case (with the PT) it is put into terms of airflow per refrence pulse of the 3x crank sensor (the 18x's higher resolution is used primarily for inj/ign timing with the cam sensor)
from what i can tell while our VE table is limited (6400rpm and 140kpa) that last cell still functions and is utilized even as you pass 140kpa and 6400rpm...before that cell read 1.55 after lots of street tuning....as soon as we did VE at the track under L/M/H load that number increased to almost 2 (the limit) while the cell just to it's left is still 1.4.
ideally the VE table would be bigger (anyone else ever hear me say stock sux lol) it still help greatly with drivability and a good bit less cell variance on subsequent MAF tunes.
this is one reason tuning Al's 04 is such a bitch....no VE, though once DD gets whitespy running i plan to continue his VE tuning (remember thats all we did the night we finished his car and the next morning when he had to leave -stock maf and maf table) and use that data to help me make manual changes to al's VE table. DD's pumping efficiency had changed radically....but the stock maf sensor and table were not modified.... hardly makes sense tuning his car with the maf, when thats not where the change is.
basically it's down to VE tune cycle (GFS into BFS and no PE), then onto true MAF tuning (GFS into BFS and no PE-remember PE does not alow the pcm to adjust FT's for proper gms/s scalling) then onto SPARK tuning.
with out the pcm being able to adjust to 14.7 on the upper maf table you just plain not getting good data.....once the no PE maf is tuned good the table is acurate....at xxxxhz the maf is reading xxxgm/s now when you enable PE it actually has proper 14.7 to 1 afr readings to be able to adjust to a proper PE afr (air is measured as VE and MAF....with the maf having the higher resolution) which in some cases is now too rich if you still have the factory/dhp 1.5 PE tables (base and rpmvstime) and the knock lobster will roar....
just ask edsel what was happening to his maf table once the PE was removed and didnt mask the true data.....
while doing primary tuning with the maf does work (esp is pe is disabled to get a true scale) and can work well, it's not the best for a moderatly to highly modded car....VE (pumping efficiency) changges with just the simple act of removing a U bend or adding an intake, and therefore should be changed....besides if your VE isnt in line...what will ya do when the maf fails/gets dirty and affects low vs high airflow readings....
one of these days we need a serious 3800 gathering where we can argue/discuss tuning etc....
based on my work with MS and accel/big stuff, the MAF is the load rationality check, actual pumping efficiency is the primary table, in our case (with the PT) it is put into terms of airflow per refrence pulse of the 3x crank sensor (the 18x's higher resolution is used primarily for inj/ign timing with the cam sensor)
from what i can tell while our VE table is limited (6400rpm and 140kpa) that last cell still functions and is utilized even as you pass 140kpa and 6400rpm...before that cell read 1.55 after lots of street tuning....as soon as we did VE at the track under L/M/H load that number increased to almost 2 (the limit) while the cell just to it's left is still 1.4.
ideally the VE table would be bigger (anyone else ever hear me say stock sux lol) it still help greatly with drivability and a good bit less cell variance on subsequent MAF tunes.
this is one reason tuning Al's 04 is such a bitch....no VE, though once DD gets whitespy running i plan to continue his VE tuning (remember thats all we did the night we finished his car and the next morning when he had to leave -stock maf and maf table) and use that data to help me make manual changes to al's VE table. DD's pumping efficiency had changed radically....but the stock maf sensor and table were not modified.... hardly makes sense tuning his car with the maf, when thats not where the change is.
basically it's down to VE tune cycle (GFS into BFS and no PE), then onto true MAF tuning (GFS into BFS and no PE-remember PE does not alow the pcm to adjust FT's for proper gms/s scalling) then onto SPARK tuning.
with out the pcm being able to adjust to 14.7 on the upper maf table you just plain not getting good data.....once the no PE maf is tuned good the table is acurate....at xxxxhz the maf is reading xxxgm/s now when you enable PE it actually has proper 14.7 to 1 afr readings to be able to adjust to a proper PE afr (air is measured as VE and MAF....with the maf having the higher resolution) which in some cases is now too rich if you still have the factory/dhp 1.5 PE tables (base and rpmvstime) and the knock lobster will roar....
just ask edsel what was happening to his maf table once the PE was removed and didnt mask the true data.....
while doing primary tuning with the maf does work (esp is pe is disabled to get a true scale) and can work well, it's not the best for a moderatly to highly modded car....VE (pumping efficiency) changges with just the simple act of removing a U bend or adding an intake, and therefore should be changed....besides if your VE isnt in line...what will ya do when the maf fails/gets dirty and affects low vs high airflow readings....
one of these days we need a serious 3800 gathering where we can argue/discuss tuning etc....
Maybe it's the tuner? I haven't done any VE tunes to the cars i've tuned and gotten fuel trims within +/-3 sometimes on the first try. Ricky's car was horrid, maxed out at idle, -16 cruising, and with 1 try i got them +/-2 which they still remain even months after. If he so much as takes his intake off forget it, the trims are wacko again but 1-2 simple maf tunes VIA MSexcel and she's back on track. He's probably got one of the best tunes I've done and it's still slow as balls 
which might be the patched together 150,000+ mile motor he's got. It's amazing that stupid thing still runs let alone knock out 12's. The ImpalaSS i tuned 2-3 weeks ago was same thing, fuel trims were maxed out everywhere, idle and cruising. I did 1 IFR scale got them withing +/-6 and 1 maf tune and it was +/-3 no VE tuning at all. Both my cars same shit, some simple math in MSexcel works every time for me. If the trims are REALLY bad I'll simply scale the IFR table accordingly to get them close enough to tune it out with the maf.
IDK we should definitely have a tuner meet to talk about how everyone does things, there's no such thing as knowing too much and i would love to hear other peoples opinions on stuff.
which might be the patched together 150,000+ mile motor he's got. It's amazing that stupid thing still runs let alone knock out 12's. The ImpalaSS i tuned 2-3 weeks ago was same thing, fuel trims were maxed out everywhere, idle and cruising. I did 1 IFR scale got them withing +/-6 and 1 maf tune and it was +/-3 no VE tuning at all. Both my cars same shit, some simple math in MSexcel works every time for me. If the trims are REALLY bad I'll simply scale the IFR table accordingly to get them close enough to tune it out with the maf. IDK we should definitely have a tuner meet to talk about how everyone does things, there's no such thing as knowing too much and i would love to hear other peoples opinions on stuff.
Maybe it's the tuner? I haven't done any VE tunes to the cars i've tuned and gotten fuel trims within +/-3 sometimes on the first try. Ricky's car was horrid, maxed out at idle, -16 cruising, and with 1 try i got them +/-2 which they still remain even months after. If he so much as takes his intake off forget it, the trims are wacko again but 1-2 simple maf tunes VIA MSexcel and she's back on track. He's probably got one of the best tunes I've done and it's still slow as balls
IDK we should definitely have a tuner meet to talk about how everyone does things, there's no such thing as knowing too much and i would love to hear other peoples opinions on stuff.
http://www.thechicagogarage.org/forum/forumdisplay.php?f=94
BOOM. Looky there, a place just for tuning talk!
Interesting that you don't VE tune @ all... what kinda math are you using to decide how to scale the IFR table? Do you dick with offset, or min PW at all... or just the IFR? Sounds crazy!
VE and maf are the primary tables.....the riv ran fine on the maf and VE table it drove there on....after more than a few light/med/high load (FT cell) VE tunes it wouldnt even idle with the maf.
based on my work with MS and accel/big stuff, the MAF is the load rationality check, actual pumping efficiency is the primary table, in our case (with the PT) it is put into terms of airflow per refrence pulse of the 3x crank sensor (the 18x's higher resolution is used primarily for inj/ign timing with the cam sensor)
from what i can tell while our VE table is limited (6400rpm and 140kpa) that last cell still functions and is utilized even as you pass 140kpa and 6400rpm...before that cell read 1.55 after lots of street tuning....as soon as we did VE at the track under L/M/H load that number increased to almost 2 (the limit) while the cell just to it's left is still 1.4.
ideally the VE table would be bigger (anyone else ever hear me say stock sux lol) it still help greatly with drivability and a good bit less cell variance on subsequent MAF tunes.
this is one reason tuning Al's 04 is such a bitch....no VE, though once DD gets whitespy running i plan to continue his VE tuning (remember thats all we did the night we finished his car and the next morning when he had to leave -stock maf and maf table) and use that data to help me make manual changes to al's VE table. DD's pumping efficiency had changed radically....but the stock maf sensor and table were not modified.... hardly makes sense tuning his car with the maf, when thats not where the change is.
basically it's down to VE tune cycle (GFS into BFS and no PE), then onto true MAF tuning (GFS into BFS and no PE-remember PE does not alow the pcm to adjust FT's for proper gms/s scalling) then onto SPARK tuning.
with out the pcm being able to adjust to 14.7 on the upper maf table you just plain not getting good data.....once the no PE maf is tuned good the table is acurate....at xxxxhz the maf is reading xxxgm/s now when you enable PE it actually has proper 14.7 to 1 afr readings to be able to adjust to a proper PE afr (air is measured as VE and MAF....with the maf having the higher resolution) which in some cases is now too rich if you still have the factory/dhp 1.5 PE tables (base and rpmvstime) and the knock lobster will roar....
just ask edsel what was happening to his maf table once the PE was removed and didnt mask the true data.....
while doing primary tuning with the maf does work (esp is pe is disabled to get a true scale) and can work well, it's not the best for a moderatly to highly modded car....VE (pumping efficiency) changges with just the simple act of removing a U bend or adding an intake, and therefore should be changed....besides if your VE isnt in line...what will ya do when the maf fails/gets dirty and affects low vs high airflow readings....
one of these days we need a serious 3800 gathering where we can argue/discuss tuning etc....
Thanks for the essay James, Interesting stuff. So I take it you are pro VE tuning? Do you mind explaining your procedure?
Maybe it's the tuner? I haven't done any VE tunes to the cars i've tuned and gotten fuel trims within +/-3 sometimes on the first try. Ricky's car was horrid, maxed out at idle, -16 cruising, and with 1 try i got them +/-2 which they still remain even months after. If he so much as takes his intake off forget it, the trims are wacko again but 1-2 simple maf tunes VIA MSexcel and she's back on track. He's probably got one of the best tunes I've done and it's still slow as balls
IDK we should definitely have a tuner meet to talk about how everyone does things, there's no such thing as knowing too much and i would love to hear other peoples opinions on stuff.
IDK if its the tuner (could possibly my scan) I simply plugged my scan and my VE table into a program that creates a new VE table based on the scanned data. We need to meet up soon (maybe this weekend) and get my tune in line. I think im going to keep my VE table stock.
http://www.thechicagogarage.org/forum/forumdisplay.php?f=94
BOOM. Looky there, a place just for tuning talk!
Interesting that you don't VE tune @ all... what kinda math are you using to decide how to scale the IFR table? Do you dick with offset, or min PW at all... or just the IFR? Sounds crazy!
Eagle, do you have lucas 42's?
PANDA, why wait two days to start tuning? I've always done exactly what you said to get into OL mode, but then used the scanner to reset the trims. Next I let the car idle until its warm and go drive, immediately logging once its warm.
The VE table is definitely used in conjunction with your MAF table. VE should be referenced mostly during light driving, where the MAF table comes into play is during WOT (or on LS1's, anything over 4k RPM on the stock tune).
I know that I've seen results from VE tuning... even on stock engines... but maybe its just me?
Do you really need to disable pe while tuning the maf? I thought you only do that for VE tuning. Sounds dangerous because you would need to hit all maf cells without pe mode.
I personally tune my maf curve before I hit my normal pe (28%) using eddies program, then I guestimate the remainder ofthe curve because I don't have a wideband yet.
Better way of doing this?
I personally tune my maf curve before I hit my normal pe (28%) using eddies program, then I guestimate the remainder ofthe curve because I don't have a wideband yet.
Better way of doing this?
I've always been told NOT to disable PE while tuning VE or MAF...
First thing that comes to mind is if you're leaving stoich @ 14.63 and trying to tune the upper cells in your MAF, you're going to be running pretty lean @ high RPM which = bad news.
Wideband tuning is the best way to go tho for sure. Much faster and less frustrating than using narrow band data!
First thing that comes to mind is if you're leaving stoich @ 14.63 and trying to tune the upper cells in your MAF, you're going to be running pretty lean @ high RPM which = bad news.
Wideband tuning is the best way to go tho for sure. Much faster and less frustrating than using narrow band data!
I was always told the fuel trims needed to settle/correct...
Well if they're settled, then the computer is already compensating for fueling issues, right? Therefore, you're not really "seeing" the areas you need to tweak. Make sense?
Another thing to note, when you're VE tuning, you should pull the all MAF PIDs out of the scanner so your data doesn't get skewed (some versions of HPT had issues with this, some even reporting it while using the latest beta), and for good measure, physically unplug the MAF (IAT has to stay plugged in of course).
Maybe this helps maybe it doesn't...
Maybe this helps maybe it doesn't...
Do you disable pe when doing a VE tune?
Also I've always been told to unplug the maf when doing a VE tune.
In theory, you should never enter PE when tuning your VE table. You're looking for smooth driving, easy transitions, lower RPM range driving. Up to 4000RPM, which is where the MAF kicks in. So disabling it shouldn't be required.
Could you explain more? It sense that you shouldn't drive in such a way to enter into PE mode while VE tuning, but disabling PE entirely doesn't seem right either... ?
Because if you enter PE while trying to tune the VE table you will lock in a particular fuel trim value, which would skew tuning results.
If it's tuned properly is the key. I do VE tunes first and am not tuned properly. I use the MAF table to tune my PE stuff. I can not risk going into PE while VE tuning, hitting boost and having something go wrong. I am not saying this is the only way to do it, but I only do VE tuning for my FTC 2 and 4.
And why wouldnt you want to hit PE without the MAF? It would just have you hit higher load areas in your VE table... if its tuned properly, then there should be no worries...
Folks that run SD tunes run without a MAF @ all and I assure you, they are hitting WOT!
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