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Single VS Dual Exhaust?

Discussion in 'The Garage' started by m1ndless, Mar 17, 2007.

  1. m1ndless

    m1ndless Banned

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    I am contemplating running single or dual exhaust, what would give me more power? Can I even run dual exhaust with the k5? Would it he hard to run?

    Would Dual 3" Exhaust be over kill and sound like crap? Maybe Dual 2.5"?

    Here are my options...

    Single 3" Exhaust
    Dual 3" Exhaust
    Dual 2.5" Exhaust
    Somthing Else?

    I will be using Flowmaster Super 44 mufflers most likley.
     
  2. BlaKK54Speed

    BlaKK54Speed 1/2 ton status

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    a single 3 or dual 2.5's will offer plenty of breathing room.

    i would compare prices, the looks, and the sound and see what you like the best
     
  3. 1990k5fan

    1990k5fan 1/2 ton status

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    Go for the Single 3" Exhaust. Mine sounds really good. Make sure your cat is running good too because before I knew my cat was plugged my flowmaster sounded like ****. Now that it was replaced, it sounds so much better. I'm really happy with it now.
     
  4. m1ndless

    m1ndless Banned

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  5. 1990k5fan

    1990k5fan 1/2 ton status

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    If you installed the single 3" you will notice a power increase. Do you have the stock or a high flow cat?
     
  6. m1ndless

    m1ndless Banned

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    Its a stock cat, but I bought a new cat (magnaflow carsound) and muffler(flowmaster super 44) , I am waiting til my next check so I can get some headers too and do it all at once.

    I guess the super 44 is a little lounder/more agressive than the super 40, yay! :D

    Would 3.25 or 3.5 be overkill?
     
  7. 1990k5fan

    1990k5fan 1/2 ton status

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    Yeah then you will notice a power gain when you swap out that big stock cat and put headers on.
     
  8. m1ndless

    m1ndless Banned

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    What if I kept the stock manifolds and just upgraded the exhaust? Could I do that and in a few months go back and do the headers, or should I be patient and do it all at once?
     
  9. 79k20350

    79k20350 3/4 ton status

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    the single 3" will be best power for a stock/ mild 350. Especially low end. also your only running 1 pipe = less to get damaged/ more room underneath...

    Also im not a fan of full length headers unless you spend the coin on the big $$$ ones. They either fit wrong or start to leak or rust out...

    There is a guy that sells stainless shorty headers on ebay, much nicer and youll have not fit issues. Being that your a 79 in AZ I doubght youll even need a cat but idk the emissons laws/ inspections down there...
     
  10. m1ndless

    m1ndless Banned

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  11. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

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    A single 3" with a high flow cat and good muffler flow plenty for a sb....

    Full length headers and single exhaust with a cat is not a very viable option.. Routing the y-pipe becomes difficult... The best option for single exhaust is a tri-y, like the Thorleys... For less performance, a shorty..

    headers are a major component of a good exhaust... Matter of fact, THE major component.. It'd be stupid to run new exhaust, then do headers a month later.. Just be a pain for the exhaust guy to mate up your new pipe to the headers... Most guys install the headers, run it down to the shop and let them hang the rest of the pipe...

    And iirc, you said you had a guy that was going to instal headers and hang a full exhaust for $135? well, thats just retarded cheap... Noone in his right mind would do that and expect to make a living.. bend pipe, hang your muffs and go from installed headers, maybe.... But just installing headers for $135 is cheap..

    Sounds like you just want the cheap, fastest done thing... You'll regret it, but hey, some of lifes lessons have to be learned the hard way... ..

    The other thing is, you said you need to smog, but haven't mentioned a thing about A.I.R.... That is a component in your emisions system.. Alot of headers have no provivion for this.. Meaning every cheapie your gonna consider buying... Most good manufacturers, Thorley, Hooker, Edelbrock, etc have provisions for A.I.R.....
     
  12. m1ndless

    m1ndless Banned

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    Hmm, thanks ryoken. So I cannot run full length headers with a Cat? I need a Cat in AZ to pass emissons. . I will be patient and save up a little more if needed.

    Can you reccomend some headers for my set up then?

    I am on a college studnts budget so its hard to be paitent to do things, lol.
     
  13. MetalCore_Blazer393

    MetalCore_Blazer393 Registered Member

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    i got dual 2 1/4 exhaust on my 87 k-5 with headman headers and i not real sure but i think its dual flowmasters too ( i bought the truck with this setup) but compared to what u said how its hard to get up to 60 i can hit the gas half way and its barks the tires from 1st-2nd and i got 35s and the only other performance part i have is k&n air filter and i have no problem gettin to 80mph+ so you should notice a HUGE change.

    o and i have my cats right before each muffler and i dont think there anything speacial
     
  14. rwillis757

    rwillis757 Registered Member

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    I have a '75 K-5 with Hooker headers and dual 2.5" exhaust. I used a pair of ??? I forgot, they're NOT flow masters....and sound GREAT at idle and low power. At high power, they're deafening..... Anyway, Duals wil easily fit, BUT.....my mechanic says that a single 3" would have given me more TORQUE.....as opposed to higher RPM HP.... (the duals SOUND good) good luck, Rob
     
  15. dyeager535

    dyeager535 1 ton status Premium Member

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    I can't quote on the y-pipe issue, (it's not the cat that is the issue, I think it's the y-pipe) but the tri-y headers seem to have the least fitment issues of the "long tube" header setups. They are still not as effective as "real" long tube headers, but more effective than shorties/block huggers, etc. Probably don't hang down as low either.

    Thorley stuff is apparently real good quality according to people here that have them, and can probably be had with any emissions stuff you need.

    If you don't need the clearance and can figure out a y-pipe solution, you could go with cheaper long tube headers, but there will likely be minor "tweaking" required to get them to fit. Very few (one or two) header manufacturers are actually smart enough to engineer their headers to clear the truck front end components, Thorley is one of them.
     
  16. m1ndless

    m1ndless Banned

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    The only thorley ones I found were clost to $400, and thats way over my budget, I might just go with some full length hookers and see how they work out.
     
  17. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

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    yeah, it's not so much the cat, it's running a y-pipe from what I've seen.. Without a cat, it leaves a little more room for finding a y-pipe location...

    Mindless, if the $379 for Thorleys is too much, I'd just get a set of Hooker comps, I think the part # is HOK-2453HKR and let your exhaust guy deal with fitting it all up... If ya gotta run duals, so be it..

    Does the truck have an A.I.R system on it? smog pump with pipes plumbed into the exhaust manifolds?
     
  18. stevos67k20

    stevos67k20 1/2 ton status

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    i sense some you guys are exhaust masters...

    i have a mildly built low rpm 454 bored to 460 and dual 2.5/flowmasters and 2.25 tail pipes. when i rev it high, it sounds like a gay lowrider (i have nothing against gays or lowriders, i just dont want my truck to have anything to do with them) you know the real poppy sound, and high rpm horsepower is crap. my engine flows a lot of air, when at idle, it will blow relaxed fingers back and blow your pants around. should i make custom dual 3" or should i just lose my tailpipes and go with 2.5 turndowns and keep my existing exhaust? or other??
     
  19. ryoken

    ryoken Puppy Fabricator Premium Member GMOTM Winner

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    yes... :D

    nice hijack... :wink1:
     
  20. rwillis757

    rwillis757 Registered Member

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    I checked my receipts, I have dual "TURBO" mufflers. nice idle and low throttle, deafening at full power. The HEADERS did the absolute most good. I put long tube hookers, fit right in , were about $150. The '75 didn't come with CAT's so that was not an issue for me. take your time, save your money and do it ONCE. Rob
     

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