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Thread: WB MAF Tuning frustration

  1. #1
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    WB MAF Tuning frustration

    2009 ZR1
    Ported blower, 108mm snout
    108mm TB
    Mamo 260 heads
    GP Tuning Stage 4 cam (no idea on specs, I bought the car with it in it and specs are only given (per GP Tuning as I asked for them) when purchased new but it isn't small)
    ID1300X2s
    Flex fuel
    Aux pump
    2.2 upper/14% lower

    I am trying to tune the MAF. I am not planning on tuning VVE at all and just plan to run on MAF. Everything is turned off (fuel trims, DFCO, CFCO).

    I am logging EQ error with NGK wideband. When I copy/paste the error, it either goes too far the other direction or barely makes a difference. I am trying to drive steady state on the highway to keep it in whatever cells for a long time. However, if I keep it in cells, they are not steady state, they will go from lean to rich or vice versa depending on which state they started in.

    I have logged from a standstill and after driving a bit and stopped the logging before I let off the gas.

    I have over 20 logs and tune variations trying to nail this down. Any help or advice would be appreciated.

    2009 ZR1 Kong original w ID1300x2 data MAF tuning 23.hpt
    19-08-31 17-36-39.hpl
    19-08-31 17-26-09.hpl
    Last edited by blake-b; 08-31-2019 at 07:33 PM.

  2. #2
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    u need to tune the VVE also even with maf only its still used, ur EOIT normal ECT is adjusted the wrong way so its best to go back to stock at least or lower less 45 then what u have now in all cells should help, makeup min pulse is too much for those injectors try 0.30 in all cells, see if that helps

  3. #3
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    Thank you for the reply. I made the changes in the tune you suggested. However, it didn't make much difference. Here are screenshots of three consecutive logs with changes made between. The only thing I can think of is human error in that I am not being smooth enough with the throttle. I am wanting to use filters and I understand the concept but am unsure how to apply them.

    I started VVE tuning but kept getting that glitch about negative entries that is cleared by waiting several minutes or a WOT run. I didn't make time for those today and continued a MAF only tune. I checked the original tune on this car
    and a tune on a previously owned 5th Gen Camaro tuned by someone else(>1200whp) and saw both were MAF only and ran well. I will continue VVE tuning on a day I have more time but I would like to figure out why I can't seem to get the MAF tuned well.
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    Last edited by blake-b; 09-01-2019 at 11:40 PM.

  4. #4
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    u also have fuel flow multipliers based on IAT and MAP so they will be playing a part all the time, injector temp offset also needs adjusting to suit the bigger injectors, ethanol sensor settings look odd and enabled, low octane spark table is equal to and higher then main spark which is not good, maf table should be smooth if its not then u have other factors u need to find and sort out, try add 5% to the entire VVE see if it helps as the areas where fuel needs to be added may be a transition to the vve, any variables to fueling are now bigger from the injector change so all the offsets make more of a difference so u will have to try put the iat and map offset back to zero and see what its like and dial it in then see if u need to add any back in or not, the offset v injector temp half it as well as it will help, u have alot to do but once its all dialed in will be much better

  5. #5
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    Thank you again for the advice. I didn't realize I had not modified the low octane table when I took timing out of the high octane table. I made them the same for the moment. I also changed the tune based on your other recommendations.

    I tried to do unloaded, idle VVE tuning and added 5% fuel to the whole table. I was getting super rich errors in the area of 27-28% and it was idling very rough. I multiplied by error and it was still 27-28% rich. I then took the whole table by .75 to try to bring it more in line. It still reported the same percentages. I let it log until the variations in the affected cells stabilized and were less than 1 percent. I did this at idle, 1000 - 2000 rpms in 200 or so rpm increments. I gave up on it for the day because it runs pretty decent in MAF only mode.

    I figured out filters and am filtering out any data less than 20% throttle. That seems to be helping the MAF tuning. I didn't get much time to do it but it looked promising. I'll continue tomorrow, weather dependent, or Friday which is my next day off.

    Thank you again.

  6. #6
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    i usually tune fueling to the lowest driving rpm/load point so its good, then i dial in idle and around fueling and blend to the lowest driving rpm areas, alot of the time free revving can use the same cells as loaded driving so its best to dial them in for driving as u need more fuel under load so free revving then will become richer, when u fail maf for VVE tuning take the maf pid out of the list so it dosnt screw any data, if ur taking 25% out of the vve and its still not changing fuel it sounds like something isnt right or ur not properly in vve

  7. #7
    Advanced Tuner jsllc's Avatar
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    Quote Originally Posted by blake-b View Post
    Thank you again for the advice. I didn't realize I had not modified the low octane table when I took timing out of the high octane table. I made them the same for the moment. I also changed the tune based on your other recommendations.

    I tried to do unloaded, idle VVE tuning and added 5% fuel to the whole table. I was getting super rich errors in the area of 27-28% and it was idling very rough. I multiplied by error and it was still 27-28% rich. I then took the whole table by .75 to try to bring it more in line. It still reported the same percentages. I let it log until the variations in the affected cells stabilized and were less than 1 percent. I did this at idle, 1000 - 2000 rpms in 200 or so rpm increments. I gave up on it for the day because it runs pretty decent in MAF only mode.

    I figured out filters and am filtering out any data less than 20% throttle. That seems to be helping the MAF tuning. I didn't get much time to do it but it looked promising. I'll continue tomorrow, weather dependent, or Friday which is my next day off.

    Thank you again.
    The rich issue is most likely due to changing injectors and not adjusting the inj tip temp table. There are many posts on this. It needs to be adjusted for your injectors.

    I run a 108 and the correct value for [ECM] 2154 - Idle ETC Area Scalar is greater than 8192, but that is the max it will take.
    2012 ZL1 - Maggie Heartbeat, Port & Polish Heads, Custom Cam, Custom rotating assembly, steel sleeved LS9, No NOS and No water meth. 16psi
    810rwhp and 820rwtq 91 Octane 6400 rpm
    948rwhp and 951rwtq 105 Octane 6400 rpm
    999rwhp and 997rwtq on 60% Ethanol 6400 rpm

  8. #8
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    Quick update, it is getting there. I just don't have much time (about 1-2 hours a week it seems) to do anything with it. I was able to get some more logs and make tune changes over the weekend. What is an acceptable MAF % error before you accept it and move on? I have less than +/- 1% in some cells and +/-5-6% in others. I've read 1%, 5%, 8%, and in Dan Maslic's book, I believe he wrote 12% was good for a big cam (going from memory what he said as I don't have the book at work with me).

    Thank you again for the advice.

  9. #9
    Tuner in Training Turbostangs90's Avatar
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    Quote Originally Posted by blake-b View Post
    Quick update, it is getting there. I just don't have much time (about 1-2 hours a week it seems) to do anything with it. I was able to get some more logs and make tune changes over the weekend. What is an acceptable MAF % error before you accept it and move on? I have less than +/- 1% in some cells and +/-5-6% in others. I've read 1%, 5%, 8%, and in Dan Maslic's book, I believe he wrote 12% was good for a big cam (going from memory what he said as I don't have the book at work with me).

    Thank you again for the advice.
    You should be able to dial it in under 5% no matter what cam.

    On the areas that are +5/6% then adjust those individually by 1/2% to bring them closer.
    2009 CTSV Sedan CRT
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    1990 Mustang tuned using Holley EFI

  10. #10
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    Quote Originally Posted by Turbostangs90 View Post
    You should be able to dial it in under 5% no matter what cam.

    On the areas that are +5/6% then adjust those individually by 1/2% to bring them closer.
    I have the MAF tuned and am working on the SD. I was having issues with SD tuning because I was only making changes to the Manifold Switch Closed table. I was not making any changes to the manifold switched open table. Now that it was brought to my attention, I am making headway.

    I believe you only need to change the manifold switch open table but I am making them both say the same thing just in case.

    Thanks to everyone who offered me advice! I appreciate it.
    Last edited by blake-b; 10-13-2019 at 10:45 PM.