Results 1 to 7 of 7

Thread: What am I missing? Not getting enough fuel...

  1. #1

    What am I missing? Not getting enough fuel...

    Not really sure what is going on here. I keep changing the MAF transfer function but my wideband is only getting marginally better - still lean. I am now virtually maxed out on the MAF transfer function and this does not seem right. I also noticed that the MAF gms/sec is very unstable.

    Possibly a bad MAF? Bad MAF placement? I don't like how they placed the MAF in this turbo kit. Did I mess up something in the tuning? I have scaled the tune for FMS 39# injectors which I believe has been done correctly.

    I am attaching the stock tune named Flash and my modified tune Flash3. I am also attaching the scan from a WOT pull to 5000 with 5 psi boost. 2005 GT.

    Any help is appreciated.

  2. #2
    Hello FirstGen,
    Being a forced induction car they're a lot more setting you have to adjust to tune this car. I took a quick look at your tune and load values are still stock, need to change Cylair WOT Multi and Cylair Max Multi, etc. You need to do the basics first for force induction. Download a force induction tune for '05 and do a compare to see what I'm talking about. You might have to disable Cylair Anticipation as well. Hope this helps.
    Last edited by Modern Muscle; 10-03-2009 at 08:20 PM.
    Paul
    Modern Muscle Motorsports
    www.modernmusclemotorsports.com
    Custom tuning using Diablosport, SCT, HP Tuners, Tuner Cat, FAST & Holley
    Dynojet 224x mobile dyno


  3. #3
    Thanks for the reply. I couldn't find anything FI in the repository or in the forum. Could you post a file or help explain how those tables work?
    Last edited by FirstGen; 10-05-2009 at 10:40 AM.

  4. #4
    Well according to the SCT software the Aircharge WOT Multplier must be raised to 1.9 to prevent clipping the MAF in high load cases (referred to as Cylair WOT Multiplier in HPT). Also same applies to the Correction for MAX Aircharge - set to 1.9 (referred to as Cylair MAX Multiplier in HPT).

    When does the Cylair Filter and Clyair Anticipation need to be turned off?

    I don't like making changes when I don't understand the background on what or why...

    I see that Paul had similar questions in an older thread. Care to share what you learned?

    Thanks.

  5. #5
    Senior Tuner
    Join Date
    Jun 2005
    Location
    Southern FL
    Posts
    2,044
    Maxing out those two scalars (Cylair WOT Multiplier and Cylair Max Multiplier) is only when you don't want the anticipation logic to be used (on the '05+ cars there is additional steps to disable the anticipation logic than just maxing those two scalars). It can be very beneficial to keep, however. But how does one do such, tho? When setting up the MAF transfer, yes, you do need to max them out initially, as well as disable CylAir Anticipation (or Filtering, depending on the year and logic used in your code), as well as potentially disabling MAF Adaption. Set the Load w/ Failed MAF tables to max (1.99) on the two highest throttle points, then dial in the MAF transfer. Once you're done dialing it in, build the Load w/ Failed MAF tables to show what you're actually logging for Load at all the throttle positions, and then re-enable all the things you disabled (from above). Everything should then fall into place.

    There's still the issue of the FPVT (fuel pump voltage table) axis limits that HPT has not yet overcome, which you being a forced induction vehicle is going to clip you, as well. You can do some searches with my username and FPVT to see what I'm referring to.
    Last edited by RWTD; 10-19-2009 at 04:45 PM.
    Formerly known as RWTD

    Toys: '22 Tesla Model S Plaid / '20 Chevy Duramax / ?20 Sea-Doo RXT-X (2)

  6. #6
    Tuner
    Join Date
    May 2006
    Location
    Bowling Green, KY
    Posts
    103
    Your MAF is working just fine. Watch your volts, as the commanded air is not following it. It is in your calibration. There are hidden limiters on how quick the numbers can theoretically go up. You will always be limited by these. They can be turned off (you still have them turned on). They will always limit how quickly the numbers actually go up in the calculations. The 1.9 number described by SCT is kind of a hack number. Stock GT500 cars have this set at .9 and it does not limit them when going from 1.2v to 4v in two to three frames of logging. This actually is not really used in the calculations as I have actually left them stock on numerous cars. It is more for instant (think .01 seconds) change in load. If you can actually increase the load by that amount that quickly, there is normally something wrong. SCT (or old Superchips) and Diablo have been changing that number to 1.9 since I started tuning the Fords 12 years ago. It doesn't hurt anything by changing it though.

    You need to turn off the cyl air filter and anticipations. This detract from driveability a little, but as long as you have all of the other fuel/load tables tuned correctly, it should not be a problem.

    Mike

  7. #7
    Senior Tuner
    Join Date
    Jun 2005
    Location
    Southern FL
    Posts
    2,044
    Quote Originally Posted by Mike@ADS View Post
    Your MAF is working just fine. Watch your volts, as the commanded air is not following it. It is in your calibration. There are hidden limiters on how quick the numbers can theoretically go up. You will always be limited by these. They can be turned off (you still have them turned on). They will always limit how quickly the numbers actually go up in the calculations. The 1.9 number described by SCT is kind of a hack number. Stock GT500 cars have this set at .9 and it does not limit them when going from 1.2v to 4v in two to three frames of logging. This actually is not really used in the calculations as I have actually left them stock on numerous cars. It is more for instant (think .01 seconds) change in load. If you can actually increase the load by that amount that quickly, there is normally something wrong. SCT (or old Superchips) and Diablo have been changing that number to 1.9 since I started tuning the Fords 12 years ago. It doesn't hurt anything by changing it though.

    You need to turn off the cyl air filter and anticipations. This detract from driveability a little, but as long as you have all of the other fuel/load tables tuned correctly, it should not be a problem.
    Mike, those scalars and their values are actually used in the logic, and serve a very beneficial purpose in the coding. If you read my post above (#5) I explained the correct procedure of tuning the anticipation logic WITHOUT disabling it on the final tune.

    As for disabling the CylAir Anticipation and/or Filtering (whether part time for initial tuning, or full time if you don't desire to use the anticipation logic, which I don't suggest disabling), you need to disable one or the other, not both. In certain calibrations the logic changed (late '07+).

    In regards to the GT500, their anticipation logic is COMPLETELY different from any other Ford. It's actually more simple and more functional code used. Ford will more than likely end up going to that logic on all the newer vehicles.
    Last edited by RWTD; 10-19-2009 at 04:46 PM.
    Formerly known as RWTD

    Toys: '22 Tesla Model S Plaid / '20 Chevy Duramax / ?20 Sea-Doo RXT-X (2)