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Thread: LNF Speed Density Tuning Anyone?

  1. #1
    Advanced Tuner silverbullet08's Avatar
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    LNF Speed Density Tuning Anyone?

    Just as you read. Mafless LNF tuning is possble through Hptuners. I have mine running flawlessly and smoother than ever before with no maf.

    Edit:

    This is how I did it. Im sure there are a few different ways to do this and will be better ways in the future. It is alot like just scaling your maf.

    First start by setting your whole maf correction table to 1s with the MAF plugged in. Also under torque managment/General/ETC limits/tq mgt inj disable set all to 0.
    Do a long datalog. And look at your LTFT. If they are off either direction use the injector constant table to make a Global change.
    Then Datalog again and repeat unitl LTFTs are fairly close to 0.
    Next use the MAF frequency table to correct for the STFT variations. Shouldnt need much. But you wont be able to get it perfect.

    UNPLUG THE MAF!

    At this point you have taught the ECM about how much fuel it will require to run. I believe the MAF frequency is tied into rpms or MAP in some form in a hidden table. Or just uses a predicted frequency. It also has control over torque a lot like the optimum spark tables. If you lower it too far you will see timing droops while making pulls. This table is now alot like a standard VE table.

    After unplugging the MAF you will have no way to monitor MAF frequency. This is fine. Your MAF correction table now becomes a lot like a VE Multiplier table like when you do a OS upgrade on a LS based engine. So if you havnt already, make a AFR error PID to fit the maf correction table along with a ST+LT PID.

    Datalog.... Datalog..... Datalog..... Copy paste special by % half the ST+LT trims into your Correction table. When It seems to be getting close you can fine tweak it further by adding the AFR error ontop of the fuel trim paste. Since we do not have loop control YOU HAVE TO DO A MULTIPLY BY% HALF WITH THE FUEL TRIMS FIRST THEN ADD THE AFR ERROR. The AFR error PID will give you the error that occured before the ecu was able to compensate then how much of the error was not compensated for after adding or subtracting fuel.

    After your done be sure to enable DFCO again.
    Hope this works for some of yall. This is the exact process I used. Now my trims are under 1.6+- at almost all times and the car runs smoother than ever before. You will get a CEL for disconnecting the MAF. Right now I have it set to MIL off after x cycles. Im going to play with disabling a few of the codes and see what happens.
    Last edited by silverbullet08; 07-23-2012 at 11:59 PM.
    HP-Unlimited Tuning and Custom Fabrication
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  2. #2
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    I would like to hear about this, but I don't get why people ditch the MAF.

  3. #3
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    how is it possible to lose the MAF?? how does the ECU measure the incoming air

  4. #4
    Advanced Tuner silverbullet08's Avatar
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    Quote Originally Posted by HydroTurboss View Post
    how is it possible to lose the MAF?? how does the ECU measure the incoming air
    If you have to ask that question then you dont understand speed density..
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  5. #5
    Advanced Tuner silverbullet08's Avatar
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    Quote Originally Posted by articzap View Post
    I would like to hear about this, but I don't get why people ditch the MAF.
    I have always liked having the maf cause of how easy it is to tune the car in, but getting rid of it makes it run amazingly smoother. It just seems like the maf is always trying to make too big of a correction on these cars.
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    2016 Camaro A8 "shop car" FIRST 6th GEN CAMARO OVER 200mph IN THE MILE 203.5mph

  6. #6
    Ok NOW your log that I saw makes a little more sense! Lol

    I was going to ask if you failed the maf for sd mode, but I didn't quite understand (still don't) how you would be able to make speed density work at this point in the tables that we have, or better yet DON'T have access to. Are you simply failing the maf and just allowing the ecm to automatically failsafe into sd mode?
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  7. #7
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    then explain speed density.........

  8. #8
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    It uses the MAP(s) instead of the MAF to measure the air.

  9. #9
    ^^and IAT's.... can't accurately measure air density without iat's and ve.
    09 Cobalt SS - E47+EFR6758 =

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  10. #10
    Advanced Tuner silverbullet08's Avatar
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    Quote Originally Posted by Freakotec View Post
    Ok NOW your log that I saw makes a little more sense! Lol

    I was going to ask if you failed the maf for sd mode, but I didn't quite understand (still don't) how you would be able to make speed density work at this point in the tables that we have, or better yet DON'T have access to. Are you simply failing the maf and just allowing the ecm to automatically failsafe into sd mode?
    Sort of.. My maf has always given me issues because it seemed too sensitive or too dull at times.
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    2016 Camaro A8 "shop car" FIRST 6th GEN CAMARO OVER 200mph IN THE MILE 203.5mph

  11. #11
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    hmmmm. NOOB here so please have patience.

    MAF measured the amount of incoming air into the intake based on the diameter of the intake pipe. From what I though I knew about the MAP it measured the pressure coming from the Turbocharger or in the intake manifold. Just curious to know how the ECU can lose the whole sensor and still get by wit the MAP.

    Like I said, im new so please clear up any errors that I have said so that I can be on the same page as the rest of you

  12. #12
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    Speed density uses other sensors in the computer to basically calculate the amount of air entering the cylinders. It know the pressure in the manifold, the rpm, and the temperature of the air. Knowing the temperature of the air, it then knows the density of the air. Using the pressure and the rpm it can calculate how much is entering each cylinder.

  13. #13
    Advanced Tuner silverbullet08's Avatar
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    moved to top
    Last edited by silverbullet08; 07-23-2012 at 11:59 PM.
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    MD800 Mustang Dyno 713-560-3889 Taylor
    2016 Camaro A8 "shop car" FIRST 6th GEN CAMARO OVER 200mph IN THE MILE 203.5mph

  14. #14
    Advanced Tuner projectlnf's Avatar
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    does it get rid of the rick spike after you shift? i have a bad case of that im all for this if it makes it run smoother lol so ill be keeping a look at this thread!
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  15. #15
    Advanced Tuner silverbullet08's Avatar
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    That could be fixed in your tune.
    HP-Unlimited Tuning and Custom Fabrication
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    MD800 Mustang Dyno 713-560-3889 Taylor
    2016 Camaro A8 "shop car" FIRST 6th GEN CAMARO OVER 200mph IN THE MILE 203.5mph

  16. #16
    Advanced Tuner projectlnf's Avatar
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    Quote Originally Posted by silverbullet08 View Post
    That could be fixed in your tune.
    are you talking about using the air fuel ratio histogram and adding it to the base maf table?
    2003 Ford excursion 6.0 PSD
    No limit intake
    Straight pipe
    Studded
    EGR delete
    KC billet single plane compressor wheel
    Self Tuned
    XDP Regulated return
    RDP Fuel sump
    AEM progressive water meth
    Custom suspension air bags
    8" lift
    35" tires

  17. #17
    God do I wish we had a way of ve tuning at idle and maf tuning for wot like basically EVERY other gm ecm/pcm out there.
    09 Cobalt SS - E47+EFR6758 =

    07 Silverado ECSB LBZ Duramax - Bunches of goodies

  18. #18
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    Quote Originally Posted by Freakotec View Post
    God do I wish we had a way of ve tuning at idle and maf tuning for wot like basically EVERY other gm ecm/pcm out there.
    Why not? There is nothing stoping you from doing that.
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  19. #19
    Quote Originally Posted by dtabbs View Post
    Why not? There is nothing stoping you from doing that.
    There are no ve tables available to touch in the e69. Only maf that i have ever seen for any lnf.... unless I'm somehow seriously missing something here.

    I can do like silverbullet did, but that's different from what I'm talking about.
    09 Cobalt SS - E47+EFR6758 =

    07 Silverado ECSB LBZ Duramax - Bunches of goodies

  20. #20
    Senior Tuner Iam Broke's Avatar
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    Those of us that have tuned LSx ECU's know of what he speaks. I had to retro learn it since I learned to tune the LNF first. lol.

    E69 is Bosch, not GM.
    '12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel