Discussion in 'Performance & Fuel' started by JManuta, Mar 10, 2010.

  1. JManuta

    JManuta New Member


    Yes I know these questions have been beaten to death, but it seems I can't find a solid answer to my questions. I've been searching the forums for a few days now. I have a 1999 Sierra 2500HD with a 6.0 in it. The exhaust has a little crimp/bend in it from backing up into a cement barrier. I am planning on getting it fixed, and I thought now might be the time to upgrade from the stock exhaust to something better since I'll be under there anyway.

    Right now the stock setup has the dual pipes going into a single inlet on a muffler with a single out going out behind the rear tire. Will replacing just the muffle, with something like a flowmaster 40 or 44, and the pipe back give me any performance boost or mpg increase? Is there any real puprose to a true dual exhaust if I were to go that way, or a single in/dual out muffler?

    Also, i was looking into a Volant CAI, and read someones post on here that it won't inrease mpg unless i get the ecu reprogrammed. Is that true? My plan for now was to get the exhuast upgraded and Volant CAI installed. Will that be any benefit or do I have to get it reprogrammed as well. Or would this setup without the tuning lower my mpg?

    FYI - Right now I'm averaging 15 mpg and it mainly stays on the highway 90% of the time to and from work.

    Thanks ahead for any input.
  2. Stealth

    Stealth Epic Member 5+ Years 1000 Posts

    Just replacing the muffler will help your truck, but the most power gains on most vehicles are found with a dual exhaust.

    TYMBOM Former Member

    You should know better than that. Single or dual on a stock vehicle(no major mods) is only for looks. Any good aftermarket exhaust, single or dual, will have gains.

    I have said it before and will again, I still have a single exhaust and am just fine.
  4. Stealth

    Stealth Epic Member 5+ Years 1000 Posts

    True, I don't think that the dual is worth the money if all you are looking for is power gains.
  5. Project Reaper

    Project Reaper Rockstar 100 Posts

    well power and mpg are different sides of the spectrum lol cant gain mpg and gain performance unless your gonna get a diesel. but if you want to just replace the muffler it will flow better and you might get a little mpg out of it. But if you go the full exhaust it wil have an effect on your mpgs. if you get a tuner that will help your mpgs. but if you want it you gotta get it all or go home lol.
  6. JennaBear

    JennaBear Rockstar 100 Posts

    X2, I have seen many a vehicle actually lose torque due to the configuration.
  7. JManuta

    JManuta New Member

    Thanks for all the input, I'll let you guys know what I do. Thanks.
  8. Stealth

    Stealth Epic Member 5+ Years 1000 Posts

    Shoot, I was wrong. Sorry guys, I won't make the same mistake again.
  9. JManuta

    JManuta New Member

    Thought I'd reincarnate my old post about upgrades now that I've finally put them in. I first put in a Volant CAI 2 weeks ago and right away saw a huge boost in acceleration. Last Friday I replaced my stock muffler with a Flowmaster Super 44 and repaired my crimped up exhaust pipe and saw decent gains with that. Tonight I bought a hypertech power programmer 3 for pretty cheap from a friend and he helped me install the program. I'm still reading more about the programmer, and still learning about the transmission shift points...I know he changed my rev limit up and changed my octane setting and a few other things, and so far I have felt a huge power gain when I get on the freeway. I am so amazed how much more power my truck has. After this next fill up i plan on doing some "regular" driving and not romping on the pedal so much (sometimes I can't help it, it just sounds and feels so nice), and hopefully I can see some mpg gains...Before I was getting 15 mpg average every tank (90% hwy), or if I drove in town a lot it would be more like 10-12 mpg. I can already kind of tell right now, based on my trip meter and the fuel gauge position that I'm getting a little bit better than usual, and it's mostly been in town driving...But after the next tank I'll know for sure what the improvement is. Thanks guys for the recommendations some of you posted!!! I love my truck!
  10. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    If you switch ALL you trucks fluids, engine,transmission, axles and transfercase you will see a small h/p and gas mileage increase.

    ---------- Post added at 11:43 AM ---------- Previous post was at 11:40 AM ----------

    O.K., I have sh*t for brains. I forgot on my last post to say switch to SYNTHETICS fliuds for a little better h/p and gas mileage.

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