change BLM min and max for quicker tuning?

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Nov 29, 2006 | 08:25 PM
  #1  
I'm tuning a new motor with a stock tpi but has different heads and cam than stock AUJP tune. I have got the idle tuned in pretty good but not anything else. knowing this engine setup is quite different in its VE than stock I was thinking to change the min and max BLM values so that I can "zone-in" on the proper A/F quicker through just a few logs and test drives. what are your thoughts?
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Nov 29, 2006 | 08:28 PM
  #2  
Sounds like an intelligent thing to do. Just make sure you set the BLM limit's back to stock otherwise if the O2 sensor takes a dump your car wont adjust and it'll run terribly. Just make sure you dont harm the car running it too lean.. always better to be a tad richer as lean.
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Nov 29, 2006 | 09:15 PM
  #3  
I actually like to set my min/max to 128/128 and tune solely off the INT.
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Nov 29, 2006 | 10:09 PM
  #4  
Quote: I actually like to set my min/max to 128/128 and tune solely off the INT.
I read your post about this but was a little confused.. what happens when the INT goes to max or min? Is it not adjusting fuel? I suppose with an ostrich you could tune the VE table in realtime to get the INT right on 128?
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Nov 30, 2006 | 11:30 AM
  #5  
Quote: I was thinking to change the min and max BLM values so that I can "zone-in" on the proper A/F quicker through just a few logs and test drives. what are your thoughts?
FWIW I don't agree with that.
By limiting the travel you are taking away the "measure" of how far off you are.
If you hit a limit, all you will know is you need more/less.
Nothing to base the amount of correction on.

If you are close, it won't use the range anyway.
Need to be close on before doing the INT only method or the same removal of "measure" is there.

I have never gotten my setup to be in the range where I could use INT only.
There is always a swing of 3-5 BLM counts when DFCO or TCC engage occurs. Just my experience.
Just my $0.02
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Nov 30, 2006 | 12:23 PM
  #6  
Quote: FWIW I don't agree with that.
By limiting the travel you are taking away the "measure" of how far off you are.
My impression was that he would open up the BLM range, not tighten it. Thus hopefully reducing the number of revisions before you're finally within the usual range of 108 to 150.
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Nov 30, 2006 | 04:34 PM
  #7  
I personally have never had much problem running INT only...even on an initial "rough draft". But that is strictly for initial NB tuning in closed-loop. Once I have my tune close to 128/128, I would set the min/max for the BLM to the stock settings.

BUT, in all honesty, tuning with a WideBand in open loop is actually the best way to tune IMO. Tuning via the NB, even when I get them very close to 128/128 shows a lot of "error" when I lock it in open loop and tune with a WB.
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Nov 30, 2006 | 05:59 PM
  #8  
It's just too bad those WB O2 sensors or so dang expensive for a student. If they werent I'd be all over one.
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Nov 30, 2006 | 06:07 PM
  #9  
I agree, LOCK the BLMs at 128 and tune with the Integrator. It responds much faster than the BLM values change. The Integrator also often resets with DFCO, DE, and AE.
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Nov 30, 2006 | 07:02 PM
  #10  
Quote: I personally have never had much problem running INT only...even on an initial "rough draft". But that is strictly for initial NB tuning in closed-loop. Once I have my tune close to 128/128, I would set the min/max for the BLM to the stock settings.

BUT, in all honesty, tuning with a WideBand in open loop is actually the best way to tune IMO. Tuning via the NB, even when I get them very close to 128/128 shows a lot of "error" when I lock it in open loop and tune with a WB.
Agreed. O2 sensor placement and exhaust system changes can greatly affect the accuracy in reporting of a NBO2. Also, there is no way to accurately calibrate the O2 thresholds to compensate for the O2's reporting "error" without a WBO2. In actuality, the NBO2 sensor is accurately reporting stoich for the exhaust gas temp it is subjected to. It is the O2 thresholds that cause the percieved "error". HTH
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Nov 30, 2006 | 08:06 PM
  #11  
Quote: I agree, LOCK the BLMs at 128 and tune with the Integrator. It responds much faster than the BLM values change. The Integrator also often resets with DFCO, DE, and AE.
I agree, response is almost instant.
Could just be the way my setup is as to why this never works for me. Trans with alot of loss below 2k rpm and a too low stall causes loads to be high at idle 58Kpa, drops lower at light cruise 40 Kpa, then pass back up to higher loads when accelerating. Doesn't like to re-cross load paths very well.
With a properly moving load range from off idle upwards it may work better in that situation.
Will try again in spring after some trans work (hopefully)
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Nov 30, 2006 | 08:10 PM
  #12  
Quote: I agree, response is almost instant.
Could just be the way my setup is as to why this never works for me. Trans with alot of loss below 2k rpm and a too low stall causes loads to be high at idle 58Kpa, drops lower at light cruise 40 Kpa, then pass back up to higher loads when accelerating. Doesn't like to re-cross load paths very well.
With a properly moving load range from off idle upwards it may work better in that situation.
Will try again in spring after some trans work (hopefully)
Sounds like a 700r4 with a stockish converter in it. Join the club.
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Dec 1, 2006 | 10:40 AM
  #13  
Quote: I agree, response is almost instant.
Could just be the way my setup is as to why this never works for me. Trans with alot of loss below 2k rpm and a too low stall causes loads to be high at idle 58Kpa, drops lower at light cruise 40 Kpa, then pass back up to higher loads when accelerating. Doesn't like to re-cross load paths very well.
With a properly moving load range from off idle upwards it may work better in that situation.
Will try again in spring after some trans work (hopefully)
I agree that IF your tune is WAY OFF, not only will it not work for you, but you will most likely hit an O2 Lean (or High) Error code. This happened to me when I was doing some initial "draft" tuning in VERY COLD weather and it affected the EGR. I found that you can "spread" the min/max on the INT and this helped (as well as some major rough changes).

If you have an SD vehicle, a good way I found to "rough" a draft bin is to take a known good bin (which close engine specs) and then use DeskTop Dyno to plot the "originating" and "new" engine specs. I then use the % change in the TQ curve between the two to make a similar % change in the VE curve (which bears a close similarity to the TQ curve).

This gets me to a pretty good draft (probably as good as one would get with one of those "eproms by mail"). And then I "fine" tune from there.

Give it a try the next time you do a "draft".
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Dec 2, 2006 | 12:43 AM
  #14  
I have had good luck in the past using this calculator when I switch the heads and cam on different engines. I use Engine Analyzer or DD2000/2003 for the HP/TQ/RPM and take my best guess at the idle vacuum. It ends up being a good starting point.

http://www.megamanual.com/v22manual/vetable.htm
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Dec 2, 2006 | 10:20 AM
  #15  
Quote: It's just too bad those WB O2 sensors or so dang expensive for a student. If they werent I'd be all over one.
BZZZZZZZZZZZZTTTTTTTTTTTTTTTTTTTTTTTTTT,

In the long term they're extremely cost effective.
Once you figure out how much money you're wasting in gas, a WB pays for itself in no time.

Install the WB, set the min and max to 128s, and have at it.

If you have to eat Peanutbutter and jelly sandwiches, skip some luxuries, well, that's the cost of tuning correctly, BTW, I'm not suggesting to you, anything I haven't done.
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Dec 2, 2006 | 09:23 PM
  #16  
Grumpy.. fill me in on the WB tuning.. I forgot to mention I have access to an LM-1 I'ma lso a little confused onwhich bin to start with.. I just used a factory AUJP to start.. but maybe the s-aujp 2 or 3 would be better? I try to follow thos threads on them but don't ever see a breakdown on what those give you over a stock bin.. all I'm looking for is a good running engine for my friend's car.. I know some people have scolded me for not connecting the VSS but no one can tell me for a fact what the negative effects are although so far we haven't seen any drivability issues without it..IF the pro's outweigh the cons then we will look at finding an inline vss sender to wire in.. but it runs pretty good so far.. I'm all ears though
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Dec 2, 2006 | 09:54 PM
  #17  
Quote: Grumpy.. fill me in on the WB tuning.. I forgot to mention I have access to an LM-1 I'ma lso a little confused onwhich bin to start with.. I just used a factory AUJP to start.. but maybe the s-aujp 2 or 3 would be better? I try to follow thos threads on them but don't ever see a breakdown on what those give you over a stock bin.. all I'm looking for is a good running engine for my friend's car.. I know some people have scolded me for not connecting the VSS but no one can tell me for a fact what the negative effects are although so far we haven't seen any drivability issues without it..IF the pro's outweigh the cons then we will look at finding an inline vss sender to wire in.. but it runs pretty good so far.. I'm all ears though
With a WB, you can lock the BL, and INT, and then do some data logging to quickly see where you are AFR wise. Then with a little practice you can see how much of a VE Table change, changes the actual AFR. Once done, while the BL might vary some when you open it up again, you'll be done. With a hipo engine the AE can cause the INT/BL to move, and that can lead you to looking for a non existant *problem*.

In fact once you have the tune right, there's no real reason for closed loop. CL is basically, to adjust for poorly maintained cars, IMO. If ALL the corrections are right, the actual AFR will remain pretty close for most any weather condition. I've been running open loop for years, and the only times I rarely have to change anything, except when they switch from summer to winter, or winter to summer fuel.

If you're running a manual tranny no biggy on the VSS, if you're running a TCC then you do want to have one.

I haven't been keeping track of the S_AUJP so I can't comment on it.
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Dec 2, 2006 | 10:15 PM
  #18  
The WBO2 is great for tuning. It allows you to tune the engine parameters open loop. Then you can go closed loop and tune the closed loop parameters to match the open loop CAL. This allows closed loop operation all the time which is better because it will correct for gas changes which you do not have control over. I once ran open loop all of the time but finally looked into the code enough to make it run closed loop all of the time while running as well as it did in open loop. It runs more consistent with different gas fill-ups. This is what I found to work best for the engines I have.

The VSS affects the fueling in the AUJP. To have it running better than what it is now you need the VSS connected.
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Dec 2, 2006 | 10:57 PM
  #19  
first of all if I wanted to lock open loop I'd just set the CL enable min temp to something above operating correct? second.. how would I log the WB as it relates to the MAP vs RPM so I know which cells to adjust? as for VSS, its a non-lockup TH350 so no computer control needed there. No stalling issues at all since I adjusted warm idle to 0 IAC counts.. it runs pretty damn good to tell you the truth.. I just want to get all this TPI has to offer over the old quadrajunk with very bad cold crankin/running problems along with some other cam/timing/idle/non-stall problems it used to have.. all that has been eliminated so it has been a success.. but I don't want to leave anything on the table as far as tuning goes.. I know the theory pretty good but not best practices and procedures so to speek. I have made an NB O2 adapter for the LM-1.. where's that auto-tuning plug-in for tuner pro?
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Dec 2, 2006 | 11:05 PM
  #20  
Yes, setting the min. temp. for CL will keep it out of CL.

For the WBO2 and AUJP you need a patch. Ask JP86SS here or do a search for it. I think Trax made a program to install the patch for you. Myself, I wrote my own WBO2 patch and assemble from a source file.

All my TPI stuff uses TH350 right now. I run a VSS on all of them. There is more to the VSS than TCC. It controls fueling modes. I hear you on the quadrajet stuff. Mine came with that too. I went to EFI so it would start in run better. It sucks when you are plowing and the carb starts dumping gas because you pushed a snow bank too hard. EFI has no problem with it.

Auto tuning is as bad as if not worse than an emulator. Once you dig deeper into engine control you will see that hand tuning is better when tuned for the engine at hand and not a generic engine. Auto-tune can only tune a generic engine.
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Dec 3, 2006 | 09:13 AM
  #21  
There is a txt file with the S_ bins to tell you exactly what changes are made to it. Traxion did a nice job of including all that info.
There are bins posted on Moates site for several of the "stock" files that have the WB patch in them. Z69' put those up last year.
there is a thread somewhere on them. Quicky search should turn them up.
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Dec 3, 2006 | 11:36 AM
  #22  
what would the WB patch give me exactly? remember this would not be a permanent install, just used for tuning. I have used aldltobin successfully on the 747s and hoped vemaster could do the same on the $8D as well.. but, it only makes corrections to the idle cell 4 because of no vss. i have a full log in datamaster though so there is data in all map/rpm bands.. i just hate the tedious process of manualy recalculation ve %.. hell this is the stuff computers were made for.. sure i can evaluate and smooth the resultant graph later but i just cant get the tables even close enough after several driving sessions..
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Dec 3, 2006 | 06:10 PM
  #23  
update.. started with the s_aujp_v3 bin, took the fuel tables from the last bin I had been working on and copied them over.. BLM no longer is stuck at 4.. works perfectly! had to reduce some timing due to knocking "no KS" at wot but VERY large improvement. so I can prob say that only thing lost due to no VSS input is highway mode and DFCO.. not a big deal. made a quick log with datamaster and ran it through VE master and it corrected VE % in all cells.. I think with a little longer log I can have it pretty near optimum. I'm not sure highway mode wont work either.. I can set the min MPH to 0 so that it would enable but what else in the code makes it work? do you just have to sustain a certain RPM/MAP area for the Highway mode delay timer?
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Dec 3, 2006 | 09:51 PM
  #24  
The SAUJP has mods for the CCP and as a result the engine will not be stuck in BLM cell 4. It will idle in the cell for whatever MAP and RPM you are at. This is a CAL change bug due to the CCP mods. For you it is actually better than what you had.

It will never be optimum without a VSS. You can get it decent but never near optimum for the handware you have because an important piece is missing. Not picking on it. It needs the VSS to run properly. It sounds like you wouldn't notice the difference. You can run it lean burn without using highway mode. The auto VE thing will not do it though.
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Dec 4, 2006 | 09:29 AM
  #25  
I'm a little confused here.. without highway mode wouldn't the 14.7 afr always be what the ecm is shooting for? how does the highway mode work exactly? I see the option for speed to enable which if I just set it to 0 that would have it enable. then I see map limits, rpm limits, and the delay timers. all these conditions could be made to work but what sets the process in motion? I think I may try getting precise RPM and MAP values at a cruising speed at around 50. Then I will set the min speed to 0 and the upper map limit just above actual and RPM limit just above actual. In theory this would activate lean cruise.
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Dec 4, 2006 | 12:13 PM
  #26  
Quote: I'm a little confused here.. without highway mode wouldn't the 14.7 afr always be what the ecm is shooting for? how does the highway mode work exactly?
% difference in the table for Hiway comes into effect.

Quote: I think I may try getting precise RPM and MAP values at a cruising speed at around 50. Then I will set the min speed to 0 and the upper map limit just above actual and RPM limit just above actual. In theory this would activate lean cruise.
Problem is, There is a speed qualifier for it. Without VSS you would be triggering those lean settings when cruising as well. Anytime the conditions were met.
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Dec 4, 2006 | 01:21 PM
  #27  
You really need a VSS, there is no way around it. I run a T5 in a 2nd gen camaro with a '165 ECU and I still got a VSS converter from jagsthatrun that just mounts inline with my mechanical speedo, and converts to pulse output for the ECU. It was like $70, no excuse not to have it.
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Dec 4, 2006 | 02:21 PM
  #28  
I agree - the VSS is pretty much mandatory for our cars....
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Dec 4, 2006 | 09:44 PM
  #29  
but without it all we lose is highway mode? thats all I can conclude
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Dec 5, 2006 | 05:36 PM
  #30  
Knock sensing is disabled without it (as you also found out)
Address 820B sets 2 MPH knock enable.
You also lose transition from idle parameters to driving, IAC functionality, Decel fuel cutoff...
Not just Hiway mode (Which is disabled from the factory and has Hiway SA as well) The combination is what yeilds the best results for milage.
Running without it can cause odd problems that are difficult to cover. You may be able to live without it but it will make things difficult in certain situations.
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Dec 5, 2006 | 06:35 PM
  #31  
JP's correct, for good tuning a VSS is a necessity. You would need to "make" major changes to the code to effectively by-pass it.

JP's listed most that I can remember, but I think there is even more that is affected - such as your fan for A/C will never turn off, your Torque Convertor won't lock, Throttle follower won't function properly, it may not pass emissions as the EGR and Canister are affected; to add a few more problems.

In fact, without a VSS, your ECM will set an SES code and go into "Safe Mode". Then your fans will probably never turn off plus you won't have most of the proms tuning capabilties operational.

Bottom line, without extensive code changes, the VSS is an integral part of the eprom's programming and will result in very poor driveability (and probably poor emissions, poor fuel economy and poor performance). You may as well chain an old engine block to your car and drag that around.
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