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Thread: Need some guidance

  1. #1
    Potential Tuner
    Join Date
    Feb 2020
    Posts
    2

    Need some guidance

    i swapped a gen 3 4.8 into my mud truck with a th400 and could use some assistance. stock 4.8 only did a cam and spring swap i put a sloppy stage 2 cam in and springs to support .im on rockwell 2.5 ton axles and 54in r2 ag tires. its my first time tuning so would appriciate any advise . already messed with my disired idle speed. played with air flow a little and the spark table. idlles good just has no balls when i put it in gear. it moves but doesnt go anywhere fast. if anyone has input please let me know .thank you. log and tune attached running moving.hplmudtruck tune running and moving.hpt

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    You're missing a couple important channels of information.

    Add knock retard, burst knock, injector pulse width avg for both banks, cylinder airmass, the MAP sensor channel. Add your front o2 sensors to the log as well.

    You will need to purchase a wideaband o2 sensor to monitor real time air fuel ratio's so you can dial in the fueling with that camshaft swap. And to make sure you don't run out of fuel. The calibration says that this engine is running 21-22lb/hr injectors, which are the smaller every offered on the 4.8/5.3 trucks. Do no be surprised if you run out of fuel at wide open throttle.

    You also need to make sure you have 58psi of fuel pressure all the time. I suggest 91 or 93 octane only in a mud truck because you are going to be full throttle pretty much all the time.

    I would say your timing is too aggressive, kinda looks copy/pasted from someone else's tune. And both both timing tables should not mirror each other, the low octane table must have less timing in it in case it has knock.

    You left the abuse mode enabled, set that to 8,000rpm and 0 mph.


    Past that I don't have enough information to go on with the log to see what's up. Not knowing if fueling is okay makes things hard. And don't expect a ton from the 4.8, you'll be lucky to make 290-300hp and they are pretty gutless down low compared to a 6.0 with way more torque.
    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
    Potential Tuner
    Join Date
    Feb 2020
    Posts
    2
    Thank you for the info . I'll will make those changes over the weekend and repost the log and see how it acts