My 4.8 needs more power. Help Me

Discussion in 'Performance & Fuel' started by whoisMDU, Jun 23, 2012.

  1. whoisMDU

    whoisMDU New Member

    what are some ways I get more horsepower out of my 07 silverado 4.8?
    I have a 05 silverado 5.3 and it runs like a race truck. the only thing I done to the 05 is add dual exhaust.

    please help
  2. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Dozens of things can be done, more air in, more air out. Duals, tune, etc. Want to spend a lot of money, add a supercharger, or a turbo.

    For the money, I think a retuned PCM is the best way to go.
  3. whoisMDU

    whoisMDU New Member

    I kind of new to the truck thing. I know PCM is powertrain control module. But is that like a Bully Dog or something. Dont laught at
  4. old school guy

    old school guy New Member

    hi just thought i would chine in i have had three 4.8's 2 where 1999s and my current is a new body 07 as power goes both 99s would eat my 07 for lunch power and milage both suck 14.5 highway old 99 i bought new would get 18+ highway . if you find an answer to this problem let me know love the truck for ride and handling also load capacity best hualing 1/2 ton i ever had but slugish on power
  5. sstoner911

    sstoner911 Epic Member 5+ Years 1000 Posts

    if I ever buy a new truck I am just going to get one with the biggest engine they got! However, the custom tune, and 4.10 gears made a world of difference for my 4.8.
  6. RallySTX

    RallySTX Member 100 Posts

    Cold air intake, open up the exhaust, and hop up the ECM, and you'll get better power. I'm not even sure you are talking about a V8 or not. But the same principals apply to any motor, I just don't know what's all out there for the 4.8.
    Brian L.
  7. larryleeUSN

    larryleeUSN Rockstar 100 Posts

    just to add to the other advice. i had a 4.8 in my 06 and i did exhaust, diablo predator programmer, cold air intake and a throttle body spacer. and after i lifted it 11 inches i ran 4:56 gears in it and it had plenty of power with 35's. i constantly pulled a 18ft car trailer with various cars and mud trucks and it was all the power i needed. you are probably running 3:42 gears so id recommend changing the gears out to a good set. and think about future plans so you wont ever have to worry about gears again.
  8. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Yeah, the Bully Dog does the same kind of thing. A custom tune is a new program loaded into the factory PCM to replace the GM program.

    From the factory, the PCM is programmed to provide good MPG and to protect (read reduce GM's warranty costs) the transmission and drive-line.

    A custom tune will remove some of the power retarding in the stock PCM, letting more power get to the wheels when the driver wants it (from a stop, or passing). Some have even insisted that the MPGs have improved.

    A word of caution... if you have warranty remaining, GM may use it as an excuse to not honour the warranty.
    Last edited: Jun 24, 2012
  9. KevAlexander

    KevAlexander New Member

    CAI would help it some, Headers, exhaust, like some of the guys mentioned, a PCM. But if youre gonna spend that much money, go with the supercharger....turbo on a truck? could work but..meh
  10. jrmchevyman

    jrmchevyman New Member

    Several things can be done to your 4.8L truck. LT headers, custom tune, shorter gears, higher stalling torque converter. Next would be a Cam or Nitrous. Next would be some kind of boost, Supercharger or Turbo.

    Just a muffler and CAI is not going to add much power, you are looking at 10-15hp max.. Long tube headers are a good idea with a free flowing exhaust + a custom tune. Those 3 in combination will wake the truck up a bit, but it still wont be a race truck.

    You do know that a 278mm 3000-3200rpm torque converter alone with a custom tune will lower your 1/4th mile times by .3 - .4 on a stock truck.

    So if it were my truck and you didn't want to get into the cam territory yet I would do this..

    LT headers, free flowing exhaust, Custom tune. When you want more after that look into a 278mm higher stalling torque converter from like circled. They act like a stock converter until you floor it and then it wakes up a bit. You can daily drive a 278mm converter just fine daily and they are not aggressive. Only thing you might want to get with the 278mm is a bigger tranny cooler like a tru-cool 40k.

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