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New Exaust, Dual or Single???

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by SandSlugg, Oct 27, 2002.

  1. SandSlugg

    SandSlugg Registered Member

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    So i have the stock exaust system, looking to get some headers and new pipes to the rear. So, lookin for opinions, dual 2.5" or single 3" are my thoughts? who has done either, do you like it, would you switch???

    also, i am looking for a good stong sounding muffler, not too loud, just a nice solid sound, suggestions???

    THX /forums/images/graemlins/pimp1.gif
     
  2. k20

    k20 3/4 ton status

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    i got dual 2.5's into delta flow 50 series flowmasters. Wouldnt change it for the world, love hte sound.
     
  3. joker89blazer

    joker89blazer 1/2 ton status

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    Do a search this has ben talked about many times. Everything else being equal 3" single or a 2 1/4" duals will give you about the same horsepower [ I saw a test on this somewhere, maybe 4-wheel mag.]. Just don't run the pipes staight out the back of the truck or you will get fumes in the truck,even with the windows up. flowmasters sound sweet, but the sound can get very tiring on long trips.On my truck I have true duals with factory manifolds and dynomax mufflers and no cats. For low rpm use you might want a crossover pipe if you use true duals. This setup is not very loud but gives a good mellow tone at idle to part throttle but when standing on the throttle it sounds really good in my opinion. A shop is most likely not going to install true duals becouse it is not legal. hope this helps
     
  4. rogerwilco71

    rogerwilco71 1/2 ton status

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    I suppose it'll determine what you're going to use your truck for. On my '77 I had header, 3" dual, with 2 chamber flowmasters--great for higher rpm hp in mud and sand. I imagine for off-road and torque you'd want 2.5" tubes and a muffler with more back-pressure.
     
  5. Sample

    Sample 1/2 ton status

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    I would go with the single 3" pipe. They look better and are perfect sized for the 305 or 350. Unless, you are going for the Redneck look, then go for the dual pipes. /forums/images/graemlins/laugh.gif
     
  6. Cmoe

    Cmoe 1/2 ton status

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    Duals:
    2.5" are to big if your going dual unless you have a big hp motor. 2.25" is a perfect dual size for a stock motor. little larger than stock exhaust but not over kill!

    Single:
    3" is great for a single.

    I ran Dual 2.25" and love them. It's easier to tuck the smaller tube up tight, compared to the Single larger pipe.

    I put the flowmaster 50's an they are just to load for me, so I'm planing on changeing to a nice softer muffler
     
  7. Stoopalini

    Stoopalini 1/2 ton status

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    I had edlebrock long tube headers running straight back true-dual style to turbo II mufflers and it got pretty bad doing 65mph down the highway. The true duals were creating a head-exploding feeling inside the cab. /forums/images/graemlins/crazy.gif

    I now have Hooker super comp shorty headers, custom Y pipe, 2 1/2" single pipe to a 3" dynamax cat, a 50 series 3 chamber SUV flowmaster, and dual 2 1/4" pipes.

    I like the single setup MUCH better. It's comfortable cruising the highway, not too loud at all. At idle, it gives a nice low tone, and doesn't get all that loud even when I slam the gas.

    What kind of a sound are you looking for? I wanted a setup that would produce good low RPM torque, and give a comfortable ride for long trips to the beach, mountains, etc. This setup definitely does all of that ..... and my gas milage probably went up too!

    Another reason I went with this setup, is clearance. The shorty headers and custom Y pipe are tucked so far up, they don't have a chance of hitting an obstacle. The single pipe is run down the passenger's side, right next to the frame rail. So it too is tucked way up underneath. I chose the passenger's side so the exhaust would be on the same side as the front pumpkin, leaving the driver's side clear for obstacle conquering /forums/images/graemlins/wink.gif LOL

    Thomas.
     
  8. meatloafK5

    meatloafK5 Registered Member

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    I like my single 3" setup but the only drawback is that you have to watch out for the front drive shaft clearance due to the crossover Y-pipe needed for a single pipe. It can limit how much lift you can add to your blazer due to the angles changing.
    /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif
     
  9. Stoopalini

    Stoopalini 1/2 ton status

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    If you use shorty headers, the Y pipe crosses over underneath the high side of the oil pan. With this setup, there are no front driveshaft clearance issues.

    That was one of the main reasons I went with shorty headers. I should take some pics, the guy who did my exhaust really did an amazing job!

    Thomas.
     
  10. k20

    k20 3/4 ton status

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    </font><blockquote><font class="small">In reply to:</font><hr />
    , you are going for the Redneck look, then go for the dual pipes.

    [/ QUOTE ] Pretty much /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
     
  11. fr8train

    fr8train 1/2 ton status

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    Dual 2.5" is what I am running. Good stuff. Like the sound, running the 40 series though. Look at my webpage for pics. of how its run. I am adding some 4" tips after I get it out of the shop. So the area around the gas tank will change.
     
  12. 84K5cedric

    84K5cedric 1/2 ton status

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    I went true dual 2.25 which I think allowed me to maintain some torque while opening it up a bit and by eliminating the Y pipe necessary in the single exhaust setup, I don't have to deal with drive shaft clearance issues. As for sound, if you want quality but not obnoxious, I recommend the flowmaster 50 series. Me... i'm cheap... I went Turbo's.
     
  13. BlazinRojo

    BlazinRojo 1/2 ton status

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    I put edelbrock headers and crossover on my stock 350. I love my flowmaster 70 series. Quite until you step on it, then you hear it. Not as louad and annoying as the 50 series, but still roars when you get on it. Go with a single 3" or dual 2.25"
     
  14. Shaggy

    Shaggy 3/4 ton status

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    <font color="green"> Just my 2 cents - if you go dual 2.5 is too big for a mild small block. Go 2.25 or you'll lose a fair amount of torque on the low end. </font color>
     
  15. 84K5cedric

    84K5cedric 1/2 ton status

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    I have the 70 series on my 96 Silverado. Great sound and I agree... at highway speeds or just maintaining speeds the sound is just noticeable. At WOT, they sound great... of course the K&amp;N filter charger makes its share of growl /forums/images/graemlins/grin.gif
     
  16. Rick

    Rick Registered Member

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    I got true duals 2.25 on mine with flowmasters 50 with headers and it sounds good they don't sound that loud to me unless you mash the gas.
     

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