Speed Density VS MAF

[Tinbender59]

I am getting ready to tune my 8.1 build, and have some questions so that I understand what I'm doing and will it get me where I want to be when finished. First this is an assembled truck, never built as far as I can find out; DBC 8.1L / 4L80E / 4X4 in a 2001 Silverado. Running a 1MB ECU don't remember the number, with a segment swapped tune.

My first question is if I do the auto VE? Can I switch back to MAF? I want the economy benefit of closed loop.

Or should I must jump straight to calc ve? I am going to be forced to understand this stuff. Lol

[Jetmech442]

My opinion is to run Calc.vet first. when your done, you re-enable closed loop. It worked great for me.

Making sure the Wideband is installed exactly as the manufacturer described is a big deal, spend some time and run the wires. Good luck man.

Sent from my Nexus 6P using Tapatalk

[Tinbender59]

The last time I tried to run a Calc VE the tutorial was incomplete, has it been updated? I hate to be a butt, but it would be nice to be able to go to one location to get the information that you need. I'm not a program guru, I am however a decent tech. Lol makes it hard for me to find what I need, when I don't fully understand the process.

[joecar]

...
My first question is if I do the auto VE? Can I switch back to MAF? I want the economy benefit of closed loop.
Yes, after AutoVE you can run the MAF (you might want to correct the MAF table, i.e. do AutoMAF).

MAF/VE are orthogonal to OL/CL (i.e. they are separate of each other)...
i.e. you can run any of these:
* VE + OL
* VE + CL
* MAF + OL
* MAF + CL
* MAF/VE + OL
* MAF/VE + CL

( where MAF = MAF-only; MAF/VE = combination MAF and VE, see table B0120 )



Or should I must jump straight to calc ve? I am going to be forced to understand this stuff. Lol

See the Calc.VET thread (the tutorial is post #1, follow any links it mentions): Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log) (https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log))

you will need a wideband.

[joecar]

MAF must have straight pipe before and after it (6" or more on each side is recommended).

[joecar]

The last time I tried to run a Calc VE the tutorial was incomplete, has it been updated? I hate to be a butt, but it would be nice to be able to go to one location to get the information that you need. I'm not a program guru, I am however a decent tech. Lol makes it hard for me to find what I need, when I don't fully understand the process.

Calc.VE has become Calc.VET, this has been updated, see post #1 here, read thru it, follow the links: Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log)


(https://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log))

[joecar]

Let me know if anything is obtuse, I want it to be clear.

[Tinbender59]

Let me know if anything is obtuse, I want it to be clear.

Yes Sir, will do. I have an LC2 with new bosch sensors, EFILive newest update. On we go!!

Is there any advantage SD vs MAF? I have always enjoyed the benefits of CL, never really cared for SD, but I would like to hear what you all think?

[ProperTuningOG]

CL is closed loop, this can operate in SD, MAF or SD/MAF.

Personally 90% of my app is off road race and I delete the MAF in everyone. Too many clogged air filters or dirty MAFs and when engines start costing 25-30K each you want them to work everywhere without fear.

On tuning street car stuff I always leave the MAF blended but fully disable and tune the SD side first. Then come back re enable and blend the maf at the point the air is steady. Depending on the intake setup, cam, heads....... dynamic crossover can vary rig to rig.

MAF only tuning to me has always seemed like the easy way out tune.. Theres too many other calculations going on to rely on maf only in my apps. None of this is just pin it to win it. We have too meany transient fuel situations that would totally disrupt steady state air.

[Tinbender59]

Wow, sounds like someone needs to start an EFILive university. IE week long training seminars.

[Tinbender59]

My problem is that I need to understand what every acronym means and how it does what it does. Then how all that works together. Lol i almost flunked electronics school because of transistor theory, talk about mind boggleing!! At the time. Lol

[ProperTuningOG]

Those are air flow basics. Nothing super special in what I typed. Basic engine knowledge and intended use seem to be rarely thought about these days. It’s just moving air. If the air isn’t moving uniformly how can you rely on a air only reading....

[joecar]

The ideas are this:
1 give the MAF a chance to read the air flow properly (straight tube for 6").
2 set PE fueling to be safe.
3 make sure PE is enable-able.
4 correct VE table (with MAF disabled).
5 correct MAF table (with VE disabled).
6 enable MAF and VE, figure out blending point/rpm (as Team208 said).

Usually, steps 4 and 5 are done with CL/trims all disabled, using only a wideband;

Calc.VET takes a few shortcuts to quicken the process:
a. it uses trims/LTFT for CL and wideband for OL,
b. it corrects the MAF table using a.
c. it also calculates a portion of the VE table from b.
d. the rest of the VE table has to be smoothed to c.
e. this VE table now has to be logged to see if it needs correction (we've seen many cases where it was ok, just needed minor tweaks for cam/idle).

[ProperTuningOG]

The ideas are this:
1 give the MAF a chance to read the air flow properly (straight tube for 6").
2 set PE fueling to be safe.
3 make sure PE is enable-able.
4 correct VE table (with MAF disabled).
5 correct MAF table (with VE disabled). This one I have found to be a problem at times if you are going to run a blended VE/MAF. In dynamic calculation the larger cams, heads, intakes, will show a different air flow on the MAF vs dynamic. Due to non steady airflow.
With the VE set perfect we will just blend the MAF to dynamic so the air flow matches. Then once in steady state you are MAF only anyway.
6 enable MAF and VE, figure out blending point/rpm (as Team208 said). This point could be hard to find at first but a good starting point is 500-1000 rpm over converter stall. After stall load if constant.

Usually, steps 4 and 5 are done with CL/trims all disabled, using only a wideband;

Calc.VET takes a few shortcuts to quicken the process:
a. it uses trims/LTFT for CL and wideband for OL, This one is another one I do different. I've seen too much surging induced from not getting a clean fuel trim during transient. Thats when it locks to the last known trim and not steady fuel trim. This can make cells not get hit with the actual trim, just the last known. This can be filtered out but takes a better understanding of what to filter out and how to get the data needed.
b. it corrects the MAF table using a.
c. it also calculates a portion of the VE table from b.
d. the rest of the VE table has to be smoothed to c.
e. this VE table now has to be logged to see if it needs correction (we've seen many cases where it was ok, just needed minor tweaks for cam/idle).


I'm just listing what works for me in my apps. This is completely different app to app, build to build and tuner to tuner.

[Tinbender59]

Man am I behind the curve on this stuff.

[ProperTuningOG]

This isn’t recreational for me. I’d hope I’m up on it. Lol

[joecar]

5 correct MAF table (with VE disabled). This one I have found to be a problem at times if you are going to run a blended VE/MAF. In dynamic calculation the larger cams, heads, intakes, will show a different air flow on the MAF vs dynamic. Due to non steady airflow.
With the VE set perfect we will just blend the MAF to dynamic so the air flow matches. Then once in steady state you are MAF only anyway.I've seen a few cam's (I'm just a part-time tuner) have an upstream effect on MAF, so making MAF follow VE makes sense (rather than vice-versa);
I'm always comparing VE-calculated airmass (g/cyl) vs MAF-calculated airmass (g/cyl).



6 enable MAF and VE, figure out blending point/rpm (as Team208 said). This point could be hard to find at first but a good starting point is 500-1000 rpm over converter stall. After stall load if constant.
ok, good to know, thanks;
points out that converter behavior allows cam to do its job, and so has an indirect "upstream" influence on MAF; good one :cheers:



a. it uses trims/LTFT for CL and wideband for OL, This one is another one I do different. I've seen too much surging induced from not getting a clean fuel trim during transient. Thats when it locks to the last known trim and not steady fuel trim. This can make cells not get hit with the actual trim, just the last known. This can be filtered out but takes a better understanding of what to filter out and how to get the data needed.
I make the transient filter to be wide enough to hopefully avoid the influence of the last known trim;
but, I would like to come up with a better filter.

I'm also playing with filtering airflow g/s transients and airmass g transients.

[joecar]

Man am I behind the curve on this stuff.
Read the summary notes (you'll run into them), get your feet wet, sanity check everything, ask questions;

remember a basic few rules:
- make sure powertrain is sound (no leaks, no noises, no overheating, no worn-out parts);
- make sure injector tables match injectors (measure rail pressure);
- air source (i.e. MAF or VE) is separate from fueling;
- set the fueling (to be safe at high load), and correct the air source;
- eliminate all but one source of air, this is what you're trying to correct;
- eliminate each trim unless you're using it to do correction (watchout for OL STFT);
- make sure wideband works properly;
- use wideband for OL (don't use trims, in OL these are not updated and so are wrong);
- filter out transients (i.e. data where throttle and/or airmass are not sufficiently steady);
- load up the engine (i.e. dyno works much better than driving uphill);
- avoid going lean;
- avoid misfires;
- avoid knocking;

fueling can come from multiple sources (the richest of the active modes/tables wins), but this shows up in the fueling pids, so you don't have to worry too much about this.

[joecar]

This isn’t recreational for me. I’d hope I’m up on it. LolIt seems like you're up, you can tell by how your customer's cars run.

[ProperTuningOG]

It seems like you're up, you can tell by how your customer's cars run.



Thank you sir.

[joecar]

As an aside-I helped my buddy with a 2006 8.1L Sierra. We found a weird issue with table B6614 where it was set to +640, which in other model years meant no torque reduction. But in this particular year it pulled nearly 50%! Setting it to
the forum clipped your reply... please go ahead and complete your reply.

[Tinbender59]

Wow!! I decided to backup and read some of the tutorials, I gotta lot of reading and learning ahead. "LUA programming language" but in the mean time i hope to have the truck tagged within 30 days. Its gotta be inspected, used 4 trucks to build her. Once tagged, i would like to get things safe until i can get "technical" like you all. Lol

[Tinbender59]

Okay I am following CALC_VET tutorial I am at step 3, (at my desk) since I do not have a LOG file, I am guessing that is why I can't find CALC.SELBEN under the DATA tab in map properties?

[joecar]

Okay I am following CALC_VET tutorial I am at step 3, (at my desk) since I do not have a LOG file, I am guessing that is why I can't find CALC.SELBEN under the DATA tab in map properties?No... you should still be able to find CALC.SELBEN...

did you download the calc_pids.txt file (from step 1) to your folder c:/users/<you>/EFILive/V7.5/User Configuration...?

in the V7 scantool, on the PIDs tab, click on the column heading Parameter (i.e. click on the word Parameter) to sort on this column (might have to click twice to get ascending vs descending order)...

look down the Parameter column until you see CALC.SELBEN.

[Tinbender59]

I did download the file and put it in (a) location, but ill double check the location,

[Tinbender59]

alrighty! I checked the location, it is correct, I have had this problem before, I cant remember what the fix was??

[Tinbender59]

Ok my fault, looking at the wrong tab

Joecar: at step 5. (or just before it) it would be nice to have it clarified whether to use the log that was taken before or should we log a new one hitting as many cells as possible?? I need to go through the notes, maybe you could incorporate the "Calc.VET: correcting MAF and calculating VE (in single log)" and summery notes into one procedure??

[joecar]

Ok my fault, looking at the wrong tab

Joecar: at step 5. (or just before it) it would be nice to have it clarified whether to use the log that was taken before or should we log a new one hitting as many cells as possible??
Use the log taken at step 2
( step 3 is setting up the maps, step 4 is applying the filters )


I need to go through the notes, maybe you could incorporate the "Calc.VET: correcting MAF and calculating VE (in single log)" and summery notes into one procedure??
I'l take a look...

[Tinbender59]

I kinda pasted them together (summery notes before #5) just my approach??
One thing for sure, if it aint clear, I'm lost lol

[Jetmech442]

previous post got clipped-probly my fault ..anywho...-I helped my buddy with a 2006 8.1L Sierra. We found a weird issue with table B6614 where it was set to +640, which in other model years meant no torque reduction. But in this particular year it pulled nearly 50%! Setting it to "0" allowed th ethrottle blase to open 100%(instead of just 53%). the truck would now roast tires without hesitation. Not sure if it will help on your model year, but thought I'd bring it up for you to look at.

Also, I can't stress enough wiring the LC2 exactly as Innovate says, with the relay and everything to the battery. I have the same WB and it's great, but other system noise will easily corrupt the signal and your tune will never converge to stability.

Yeah, theres a lot to learn and read and re-read, I was there a few years ago, but it's well worth it and totally addicting.

[joecar]

setting B6614 to zero:

ok, thanks, I'll keep this in mind.

[Tinbender59]

previous post got clipped-probly my fault ..anywho...-I helped my buddy with a 2006 8.1L Sierra. We found a weird issue with table B6614 where it was set to +640, which in other model years meant no torque reduction. But in this particular year it pulled nearly 50%! Setting it to "0" allowed th ethrottle blase to open 100%(instead of just 53%). the truck would now roast tires without hesitation. Not sure if it will help on your model year, but thought I'd bring it up for you to look at.

Also, I can't stress enough wiring the LC2 exactly as Innovate says, with the relay and everything to the battery. I have the same WB and it's great, but other system noise will easily corrupt the signal and your tune will never converge to stability.

Yeah, theres a lot to learn and read and re-read, I was there a few years ago, but it's well worth it and totally addicting.


Good to know stuff, thank you. My 8.1 is sporting a cable TB?? Should be interisting!! Lol.

Later today I'll post the start tune that I created with the help of LEXTECH, basically a 6.0/4L80E tune, that I copied every line dealing with the motor out of the stock 2004 8.1 tune line by line. It took a bit of time. Lol

[Tinbender59]

If any one would like to see what I'm building? Look here - http://www.silveradosierra.com/under-construcktion/tinbender-s-ultimate-2001-k2500-build-t593361.html

[Tinbender59]

My home brewed tune, if someone would like to critic it I would welcome any suggestions. I do however have a question in Injector flow rate.

I cant find any data that makes sense, what should I put in there?? my 8.1 is completely stock, with vacuum referenced fuel pressure, (has a vacuum line going to the regulator on the rail)

22019

[Tinbender59]

I was comparing the tune to the factory 8.1. Wow it is a mess, I guess I'll spend some more time on it, lol. I have a good tune for the 411, and a 411 with licence, May go ahead and pop that one in for now. With the 1MB ECU I am having some weird dash issues. No 4X4 light, gear indicator changes how it acts with every start?? I did prove that 4X4 is working?? Also dead in the water until the new diaphragm for the regulator shows up, kinda leaking - "bad".

[Tinbender59]

Well it appears that I have a small problem with my tune, it is not going to do what i want. With that said does anyone have an idea where i can find a DBC 4X4 4L80E tune for the 12586243 1mb ecu? motor size is not important

[joecar]

My home brewed tune, if someone would like to critic it I would welcome any suggestions. I do however have a question in Injector flow rate.

I cant find any data that makes sense, what should I put in there?? my 8.1 is completely stock, with vacuum referenced fuel pressure, (has a vacuum line going to the regulator on the rail)

22019With MAP-referenced FPR do this:
- temporarily remove reference hose (leave FPR open to BARO);
- measure rail pressure (aka "base pressure"), should 58 psi +/-1 psi;
- if FPR is adjustable, adjust rail pressure to 58 psi;
- remember to reconnect reference hose.

note: some vehicles run base pressure other than 58 psi.

Measured base pressure is used to scale injector flow rate.

Also note that with MAP-referenced FPR/rail pressure, the IFR is flat (same value in all cells).

[Tinbender59]

I have a couple of new problems, my gear indicator is not working correctly reads R, D, and 2, and the 4x4 light does not illuminate but it is in 4x4?? hum??

[joecar]

Post your original tune, and your current tune ( is this it: NEW_BIG_TRUCK_0000.ctz (https://forum.efilive.com/attachment.php?attachmentid=22019&d=1524273338) )

What segments did you swap, and from where...?

[Tinbender59]

here is a better tune 22031

on this tun I started with a 6.0l 4X4 4l80e , told it that it was not DBW, and then pulled all motor data, line by line, from the original 8.1l ECU that was different than the 6.0l into my tune. I did find injector data in another tune. should work better, "I hope" as soon as the diphram for the regulator shows up Ill find out

[joecar]

Do gear indicator and 4x4 indicator show correctly...?

[Tinbender59]

Ill know tomorrow, at work at the present time

[Tinbender59]

Do gear indicator and 4x4 indicator show correctly...?

Im guessing that the "tune" decodes the binary data from the natural safety switch then feeds it to the dash via the serial data bus? And the Allison decode is different than the 80e???

[joecar]

Im guessing that the "tune" decodes the binary data from the natural safety switch then feeds it to the dash via the serial data bus? And the Allison decode is different than the 80e???For the PCM controlled Hydra-Matics, yes... for the Allisons, I don't know.

[ScarabEpic22]

All Allisons have a separate TCM, AL5. This includes both Duramax and 8.1/Allison combos. The LS1B when paired with the Allison in the 8.1, not sure what information is sent to the TCM but I imagine it's closer to what the LB7/LLY sends the AL5 than what other gas engines send/use for 60E/80E/NV 5spd.

Looks like your tune has the 80E segment so you should be good there. Also this is an 04 OS, just FYI, so if it was from a truck or Vette it would be DBW. I've been told that only Vans were DBC in this timeframe, and only if they didnt have traction control (StabiliTrak = DBW need to have the PCM close the throttle). I've had good luck simply disabling DBW on PCMs that have it enabled, but it requires the PCM to have the IAC driver actually on the PCB (not all 1MB PCMs do).

[Tinbender59]

All Allisons have a separate TCM, AL5. This includes both Duramax and 8.1/Allison combos. The LS1B when paired with the Allison in the 8.1, not sure what information is sent to the TCM but I imagine it's closer to what the LB7/LLY sends the AL5 than what other gas engines send/use for 60E/80E/NV 5spd.

Looks like your tune has the 80E segment so you should be good there. Also this is an 04 OS, just FYI, so if it was from a truck or Vette it would be DBW. I've been told that only Vans were DBC in this timeframe, and only if they didnt have traction control (StabiliTrak = DBW need to have the PCM close the throttle). I've had good luck simply disabling DBW on PCMs that have it enabled, but it requires the PCM to have the IAC driver actually on the PCB (not all 1MB PCMs do).

Thank you, yes my pc is a 6243 with IAC drivers on board, the gear indicator and 4X4 light issues still exist after complete reflash. I'm guessing the TC switch may bad, ill get into it later. Jamming hard to get it ready for title inspection the first of next week

[ScarabEpic22]

Thank you, yes my pc is a 6243 with IAC drivers on board, the gear indicator and 4X4 light issues still exist after complete reflash. I'm guessing the TC switch may bad, ill get into it later. Jamming hard to get it ready for title inspection the first of next week

I'm trying to piece the build together, it's a 99 frame, 01 8.1 DBC converted engine, 4L80E trans, 01 body, and an 04 1MB PCM? What transfer case?

I've only seen DBW 8.1s from GM too so this is a cool conversion!

I was wondering if the TC switch is a different P/N for the different years/engine/transfer case options...

I did find an 01 Silverado with the 8.1 and segment swapped the 80E transmission segment in from another 01 Silverado LQ4 (attached). Since you have a 0411 licensed, if you wanted to check a 512kb PCM this would be a good base file to start with. Again, it's stock so it's DBW enabled, you'd have to turn that off in the Platform options.

[Tinbender59]

My bad TC is a 261 manual shift. I've been thinking about this quite a bit have the wiring almost memorized, lol. It has to be either the one half of the switch on the TC, ( two switches internal) or a missing ground that feeds both circuites? I hope to dig into it this weekend. The 4X4 does lock in and release on command???


On another note, inspection Monday at 11:am, and alignment Tuesday at 10:am. I'll get the tags Tuesday while it is in the alignment shop then I'll get to drive it home, and put 25 miles on her. Shakedown trip!!

[Tinbender59]

I'm trying to piece the build together, it's a 99 frame, 01 8.1 DBC converted engine, 4L80E trans, 01 body, and an 04 1MB PCM? What transfer case?

I've only seen DBW 8.1s from GM too so this is a cool conversion!

I was wondering if the TC switch is a different P/N for the different years/engine/transfer case options...

I did find an 01 Silverado with the 8.1 and segment swapped the 80E transmission segment in from another 01 Silverado LQ4 (attached). Since you have a 0411 licensed, if you wanted to check a 512kb PCM this would be a good base file to start with. Again, it's stock so it's DBW enabled, you'd have to turn that off in the Platform options.

thank you for the time involved in locating these tun's. i will load them and see what happens. do these have the "Lift - Shift issue" in the 4L80E fixed? Also just to clear things up, both of these tun's will work in my 411?

on a side note the gear shift indicator does "eventually" figure itself out??? not sure whats up there? currently chasing the little gotcha's that are inherent to a project of this magnitude, and my ignorance. lol

I am having some issues, here is a copy of my tune and a short scan
22200

22201

i'm not sure whats up here, other than this is a cobbled together tune??
but I am trying??

P.S. still haven't made it to inspection, but I am still moving ahead with the work.

should I start a new thread???

[Tinbender59]

Well i guess ill just start over, look for the new thread coming.