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Dual 3" Exhaust on a 6.2 diesel

Discussion in '1982-Present GM Diesel' started by josephn, May 27, 2002.

  1. josephn

    josephn 1/2 ton status

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    Dual 3\" Exhaust on a 6.2 diesel

    I would like to know if anyone has done this and how did you like it? Because my exhaust is shot and I need to get it redone and would like to do it 3". I already have dual exhaust and don't want just a single 3" pipe like on some of the other exhaust kits that I have seen.
     
  2. Dirty Dave

    Dirty Dave 1/2 ton status

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    Re: Dual 3\" Exhaust on a 6.2 diesel

    I got some info on this from several sources but went with 1 3 inch pipe well a 3 to 3.5 because I will be going to a turbo soon.

    While waiting at the muffler shop a guy came in pulling a drag car. He was driving a blazer like me with a 6.5 N/A transplanted. We got to talking and he said he had hummer headers to 3 inch pipe to the rear axle with a H pipe . Over the rear axle he went to 3.5 and before the turn behind the rear wheels he went to a 4in pipe. This way, so his thinking was, the pipe was not restricted as much by the bends staying close to 3in all the way. Make sense? He took we for a ride in his blaze and it was by far the strongest N/A diesel I have ever rode in.
    It had some work done to it but he said the exhaust made a hell of a difference. Lee Swager over on the Diesel Page has 3in duals with a H pipe on his hot little 85 6.2.

    If you want to use 3in pipe you will need an adapterat the manifold to get the best results.
     
  3. arveetek

    arveetek 1/2 ton status

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    Re: Dual 3\" Exhaust on a 6.2 diesel

    I'm using adapters designed by Dr. Lee from the diesel page that I had made at a local machine shop that allow me to bolt up 2.5" pipes directly to the stock exhaust manifolds. The stock setup only allow a maximum of about 1 7/8" pipe to clear the three studs on the manifolds, so adding 3" pipes after that doesn't help much with such a big restriction at the beginning. The actual opening of the exhaust manifolds is close to 2.5", so this is the biggest pipe than you can really get on the stock manifolds. Of course, headers are the best flowing option, which allow you to bolt up 3" pipes, but they're so expensive for the diesels that you'd be better off investing that money into a turbo setup.

    My 2.5" pipes leave the manifolds and then turn into dual 3" pipes as soon as possible. This is on my '81. I am currently running dual 3" side pipes that you find on race cars and such. I will soon be doing away with them once I get my turbo installed.

    I would also recommend an H pipe if you can. I think it helps a bunch on the diesels.

    Once I get my turbo installed, my exhaust system will consist of a 2.5" cross-over pipe, a 3" downpipe, turning into a single 3.5" pipe, possibly even into a 4" tailpipe.

    Casey
     
  4. josephn

    josephn 1/2 ton status

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    Re: Dual 3\" Exhaust on a 6.2 diesel

    I am tempted to fab my own headers with a 3" collector to make it easier. Do you know of any headers that have 3" collector for the 6.2? I really like that guys idea with his 3.5"-4" Pipe on the curves I just might try this. Pretty cool.
     
  5. Dirty Dave

    Dirty Dave 1/2 ton status

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    Re: Dual 3\" Exhaust on a 6.2 diesel

    If you can find some Hummer headers you'd be set. They are the shorty style but they work. They are also what the guy above used.

    I have purchased a set on e-bay for 150.00 brand new and plan to put them on the M1008 I'm about to get. I will also go with the same system the guy had on the blazer. Which by the way I had my single pipe ran that way.

    Dont know if it works but it makes sense to me.
     
  6. josephn

    josephn 1/2 ton status

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    Re: Dual 3\" Exhaust on a 6.2 diesel

    Cool, I will look for some Hummer Headers. If I can't find any I am just going to bust out the pipe bender and welder and make some of my own.

    Thanks for your help. /forums/images/icons/smile.gif
     

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