X & H pipe vs straight dual exhaust

Mopar Exhaust Systems

  1. crackedback

    crackedback FABO Gold Member FABO Gold Member

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    This discussion brings to mind one of my favorite jokes.

    What does 80 yo pussy taste like? Depends...

    There is no definitive answer as to which system works best for every engine... PERIOD.

    tti can claim 15hp or whatever. I've seen cars slow down using an X. Also seen them pick up. For tti, that particular set up liked the X, much like Myron's race car liked the X system. It is totally combination dependent.

    Most engines that are street driven, aka 400-450hp or less tend to like an X or some type of crossover.
     
  2. Mopar to ya

    Mopar to ya Well-Known Member

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    I had straight duals on my 408. It rapped at low speeds and on decell. I was embarrassed. I went to true rolled 3' out of my TTi's and put in an H pipe. It goes into dual Flowmaster 40's and rolled 3" tailpipes out the rear. It sounds good and I no longer have that stupid rapping problem. My brother always said it sounded like a Chevy before I changed it.
     
  3. 1Fast340

    1Fast340 Well-Known Member

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    im not saying they are no good at all,but they sure has to create restriction from turbulence considering the design. i have looked at hundreds of X-Pipes of different brands and types and made quite alot of them aswell. the problem with the pressed sheetmetal type X-pipes is that they all have tubefittings stuck into the X-part that is almost like a chamber these fittings are not welded edge to edge with the sheet x section the tube fittings create a step. and therefore must be a restriction. might not be a problem at the inlett side but sure has to be one on the inlett side.

    think of the X section as a piece of 3" tubing with the fittings being 2½"tubingstuck into the bigger tubing and then a fat weld around them. then look into the bigger tube and you will understand what the exhaust pulse will look at trying to exit these xpipes.


    i suck at explaining stuff like this. much easier being able to point at the problem with a product in hand.

    the only reason i can see for that designs popularity is that its cheap to make and very universal for a manufacturer.
     
  4. Lelo Dart

    Lelo Dart * FABO Gold Member

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    Huge / Wide open in there, can't see the problem. Must be thinking of something else:dontknow:
     
  5. bamamopar

    bamamopar Well-Known Member

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    Over straight to mufflers there was a pretty good gain with my 3in X pipe exhaust. It sounds killer.
     
  6. bamamopar

    bamamopar Well-Known Member

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    Sorry for the bad video but here is my 300 buck x pipe new super 40s [ame]http://static.photobucket.com/player.swf?file=http://vid1104.photobucket.com/albums/h336/bamamopar/VIDEO0022_zps3cd75041.mp4[/ame]
     
  7. 1Fast340

    1Fast340 Well-Known Member

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    a quick googlesearch gave me this pic.lets hope it work. not uncomon to see bigger steps inside them,but there is a step visible.

    [​IMG]

    would you accept if a person porting your heads left a step like that in a port?
     
  8. Lelo Dart

    Lelo Dart * FABO Gold Member

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    Those dang mufflers most really mess up the flow then huh?
     
  9. 72BBSwinger

    72BBSwinger Well-Known Member

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    X pipes do have the potential to have to tight of a merge and can take your exhaust from being a dual 3" system to a single 3.25" system at the merge. Does that make sense??
     
  10. ir3333

    ir3333 Well-Known Member

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    ..Larry Sheppard,Mopars' head engineer for their Direct Connection program says an H pipe
    produces no increase in hp.An H was installed on some factory models to quieten the exhaust
    and allow the use of less restrictive mufflers.
    ...the H should be smaller than the exhaust diameter and be located 12 to 16 inches back.
    ...i have no experience but it's hard to believe a 6 inch piece of pipe could make any power?
     
  11. 1Fast340

    1Fast340 Well-Known Member

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    would you accept that kind of step in a exhaustport? i wouldnt.
    the point with an X-pipe is to keep velocity high enough to help pull the next pulse coming in the other pipe thru the exhaust that big box wont do that and those steps will create turbulence.

    will it restrict power in any noticeable way on most streetcars? probably not a big isue.

    is it the best way of doing it? i can guarante its not.

    is it good enough? thats your choice,but when you are building a performanceexhaust why would you settle for something that is worse than it has to be?

    some would say oh well that thing will be good enough since its not a racecar, i would say think a few steps further and try to use the best workign pieces the whole way and the car will run stronger and be alot more fun without spending more money.
     
  12. Lelo Dart

    Lelo Dart * FABO Gold Member

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    Sorry, just giving you a hard time. Can you give an example of the good X pipe?
     
  13. rod7515

    rod7515 Well-Known Member

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    Thanks for all the feedback so far. There have been many different thoughts on this subject and in the end it looks as though I may be just as good to use a straight dual exhaust system. I plan on using the flowmaster 40 series mufflers but the jury is still out on an X or H pipe or just go straight thru exhaust. I was happy to see a 15 HP gain but then others say there is no gain. If its only a noise reduction, not sure if its worth the cost.
    Rodney
     
  14. BrianT

    BrianT Let's go!

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    Me too! Like I said before I'd be interested in learning all I can before making my decision.

    I strongly suggest that you research your exhaust more before throwing on a set of Flowmasters and not running some sort of cross over pipe. My Flowmasters had a drone from the exhaust at highway speeds that made the car no fun to drive, and that was with a H pipe. There are much better mufflers out there that flow just as good.
     
  15. Lelo Dart

    Lelo Dart * FABO Gold Member

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    Now this is a x pipe!
    :burnout:
     

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  16. RJS

    RJS Well-Known Member

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    I don't know how all these experts come up with some of this stuff??
    I've never seen a 71 Charger 440 6pack without an H-Pipe.
    Infact back in the summer of 78 we took my friends original exhaust off his Charger when we put headers on and were about to toss the Original H-Pipe when another friend pulled up and grabbed it like it was gold for his 383 car.

    I know my 70 Cuda 440+6 didn't come from the factory with an H-Pipe but Hemi's did.
    Ron
     
  17. 1Fast340

    1Fast340 Well-Known Member

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    its a hard one realy, most you find in a box made out of mandrelbends would be ok if they just got two things right about them.

    one thing that sucks with alot of them, the monkeys that make them rarely debur the cuts before final welding wich looks like crap and might create alitle turbulence,,its also quite comon to see that noone took the time to match the two sections togheter giving what i consider another chance of turbulence with the two openings cut out of the bends not fit togheter right.

    i used to make x-pipes and created a design for the company i worked for without much actual testing but with good craftsmanship and pride in makeing the parts fit togheter right.

    in the very simple backyardstyle testing i did i found that you dont realy need a very big hole betwen the two tubes to create a strong pull thru the opposing tube. it was mostly about attention to detail on the cuts realy. im sure welmade parts from some brands makes slightly more power due to more scientific testing but just attention to a good fit betwen the parts seem to be what is important and i would avoid cutting out to much since there realy isnt a point in doing so.

    for simplicity compare TTI X-pipe for an abody to alot of the cheaper universals and you will get a pretty good idea about basic differences in cutting the bends.
    i also like to use less than 90 degree bends for neat packaging under the car and less restriction. with the front section being wider spread than the rear section.

    avoiding to get into to much details to avoid any trouble with my previous employer (its not TTI or any of the big american brands) that im still on good terms with and want to keep it that way and considering the possbility this somehow managed to get trademarked or similar since i left.

    hope it helped a little hard to explain in text.
     
  18. airwoofer

    airwoofer Drivetrain limit explorer

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    I had similar results going from TTI headers (open) to a 3" X-pipe into 3" flow 40's and then dumps. Even with the added weight the 1/8 ET went from 7.25 to 7.20. I later added 8" long cherrybombs in front of the flows to take away the raspy sound. I love the way that exhaust system sounds with my 416.

    And "one thing that sucks with alot of them, the monkeys that make them rarely debur the cuts before final welding wich looks like crap and might create alitle turbulence" I agree and used a round file to deburr the Summit X pipe so it could cross over better before the exhaust guy welded it all up.
     
  19. Oldmanmopar

    Oldmanmopar Going left turning right FABO Gold Member

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    Flush two hoppers with loads in them at the same time. See what happens when they meet at the X. I rest my case.
     
  20. Oldmanmopar

    Oldmanmopar Going left turning right FABO Gold Member

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    If you make more power by adding an X to your oversized exhaust. You didn't need the X you needed a smaller exhaust or a much larger motor.
     
  21. 72BBSwinger

    72BBSwinger Well-Known Member

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    Chrysler must not of gotten your memo about how sucky X-pipes are Old man because they have been in almost every SRT-8 since 2005. You need to tell them they're doing it wrong! Might as well tell Chevrolet, Ford,BMW,Mercedes,Ferrari and Cadillac while your at it.
     
  22. mvh

    mvh FABO Gold Member FABO Gold Member

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    One the other side...
    My muffler guy recommended against any kind of crossover. My car of course is a completely different ticket than a big block with headers -- 273 4bbl with manifolds and 2.5" back to dual Super Turbos. I don't think HP/torque was even considered -- he thought it would kill the sound... not to mention get in the way when monkeying around underneath. He seems to have a good idea what I'm about :)
     
  23. Locomotion

    Locomotion Well-Known Member

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    I guess Nascar teams use X-pipes as another form of "restrictor plate"?
     

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  24. crackedback

    crackedback FABO Gold Member FABO Gold Member

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    Hoppers DO NOT pulse like an engine does. Entirely different flow environment.

    In that case every engine should have zoomies because you have a jam up at a 4 into one collector.
     
  25. rklein383

    rklein383 Well-Known Member

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    I wish everyone would say what they really think....
     
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