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Thread: LS4 TB Tuning Data

  1. #1
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    LS4 TB Tuning Data

    Has anyone successfully installed a LS4 TB on a LSJ and got it to idle factory smooth. I have got this car dialed in very good. But the idle is still jumping around +/-150rpms from desired idle rpm.

    I have messed with the ETC Scalar quite a bit with different numbers. Around 4950-4500 have seemed to be the best so far, but not perfect like I would like.

    This is a tubro LSJ, stock camshafts. Idle is set about 1,000rpms. Car also is on 93 octane with 80lb/hr injectors. Just recently lowed fuel pressure from 58psi to 43.5psi to try and get the idle better. If anyone has some good pointers, it would greatly be appreciated.

    Thank you

  2. #2
    Senior Tuner cobaltssoverbooster's Avatar
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    I don't have time to explain all the details but yes.

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    Is there a thread already that has the information in it?

  4. #4
    Senior Tuner cobaltssoverbooster's Avatar
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    the jist is: it all comes down to your skills in tuning injectors. any errors on the base setup are worsened by oversizing the throttle since the plate moves in a smaller range for idle control.
    2000 Ford Mustang - Top Sportsman

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    So I need to make sure I did all of my injector scaling correct then. If I post up my tune file. Can you check the injector tables? I based mine off of Omega's Excel spreadsheet that he made for the 80lbs.

    I have another question, would 80lbs be better to control on 43.5psi? Or should I keep fuel pressure at 58psi? I currently have them scaled for 40lb @ 43.5psi with a 2 on the multiplier. I figured lowing fuel pressure would allow the injectors be easier to control at idle. On 93 octane.

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    a long time ago a few of us went over injector offset tuning. there should be a file in here somewhere that tells you how to verify them. if you cant find it just search injector offset tuning in google and one of the aftermarket ecu forums has a how to that is right on point with what we had to do. i kept my first post very vague because i do not have the time to look at anything right now. basically i have just enough time to pop in every once in a while to check the flow of information.
    2000 Ford Mustang - Top Sportsman

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    Alright, thank you for the information.

  8. #8
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    to properly run the ls4 tb on the lsj engine you need the pedal from the ls4 car, tac coding, and bcm reflash to run it properly.
    The most hated, make the most power.
    93 Ranger. 5.3 D1X. 1069hp.

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    Are there gains going with LS4 TB on turbo'd LSJ? Debating going back to stock TB but I made a custom manifold with LS4 TB flange, so I will have to figure that out.

  10. #10
    Advanced Tuner Japeatr's Avatar
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    the LSJ and LS4 is the same bolt pattern

    384whp/303wtq
    Built 2.0LSJ: TVS w/2.6, 1000cc, Stage 2 cams, custom fuel system, E85, Dual Pass, 3"intake, 3" Catless exhaust, CIA midlength Header