Results 1 to 5 of 5

Thread: Need some help

  1. #1
    Tuner in Training
    Join Date
    Feb 2011
    Posts
    38

    Need some help

    I am helping a buddy with a LS swap in a RX-7. The swapped motor is a 5.3 from an 01 Tahoe with a car intake. The motor runs really bad with MAF connected, and the fuel trims are going up to 50. The o2 sensors are staying low. If we disconnect the MAF, the car runs pretty good, the fuel trims are within 10 and the o2 sensors seem to be working normally.

    Any ideas? I'm pretty new to tuning and such. Thanks

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    You must tune the motor for the change in intake manifold. The MAF and VE tables are now going to be way off because the truck intake design is different from the car intake.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner in Training
    Join Date
    Feb 2011
    Posts
    38
    Quote Originally Posted by 5FDP View Post
    You must tune the motor for the change in intake manifold. The MAF and VE tables are now going to be way off because the truck intake design is different from the car intake.
    Thanks. Can I just copy the tables from somewhere, or does it need to be dyno tuned?

  4. #4
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    You can do everything with real world driving, no dyno needed.

    And no you can't copy and paste from anywhere, they never made a 5.3 with a LS1 style intake.


    You'll want to invest in a wideband if you don't have one and look up how to VE and MAF tune the car and go from there.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    Tuner in Training
    Join Date
    Feb 2011
    Posts
    38
    I see, thanks