Any real benefit to an H pipe compared to regular dual exhaust?

Discussion in 'Classic Mustang Specific Tech' started by jerry S, Jan 4, 2006.

  1. I have had somebody offer to fit an H pipe on my nearly new set up. I am wondering if it would be worth it.
  2. Dyno-proven that you will gain power.

    ~5-7rwhp. So if it is just a cruiser, then you have to justify the dollar to horsepower ratio. If you are concerned about getting all the power you can, go with the h or x or what have you.
  3. if you have the room the x pipe is better as it will flow smoother. I have the H pipe as that is what came with my flowmaster kit.
  4. Better scavenging, exhaust pulse balance, and a quieter tone.
  5. Ditto, but I too, vote for the "X" pipe route, or what I did on my 89 Ranger: built an "equalizer" chamber pipe. This is a foot long 4" pipe that the two exhuast pipes run into, then exit back to duals between the collectors and mufflers.
  6. Well, I just did some internet research and my preliminary conclusion is that between the X and the H, the H is the better way to go. First, I found a tech note from Flowmaster's FAQ. Have a look

    Do I need to install an "H" pipe to my dual exhaust?
    Flowmaster strongly recommends using an "H" pipe, commonly known as a "balance tube" on all "true dual" exhaust systems. An "H" pipe equalizes the pressures between both banks of the engine giving a broader and flatter torque curve throughout the rpm range. It also eliminates "back-rap" common on deceleration, and creates a deeper mellower tone both inside and outside of the vehicle.

    Is an "X" pipe better than and "H" pipe?
    Over the years, Flowmaster's testing of all types of crossovers, including "X pipes", has revealed no substantial benefits over a properly installed "H" pipe on street driven applications. However, in race applications with small cubic inch engines and /or restricted (small bore) carburetors, will respond well to the addition of X pipes, tri-y styled collectors and/or properly designed single exhaust systems.

    Then, I found an article from Mustang 50Monthly in which an X and an H were tested side by side. The H came out on top.

    Finally,, the H is easier to install on my current set up. Just cut and weld. More work would be involved to get the X to fit.

    Attached Files:

  7. Actaully, the dyno chart you posted above is from the cat-convertor equipped X & H pipes. It's not apples-to-apples, as the two pipes used different convertors.

    What you really want to look at is the "off-road" (non-cat) X & H pipe dyno test, which clearly show the X's better numbers.:nice:

  8. I stand corrected. I thought that chart I posted was the off road one. I still wonder about the FAQ from Flowmaster saying that the H Pipe is the best way to go. In my case, the H is really a simple install. And at the end of the day, the X only makes about 5 more hp and ft. lbs. torque.
  9. if you look at the second chart, you will see that the X pipe, while having an advantage over the H pipe, the advantage doesnt become clear untill the rpm's go over 3500 rpm. fine for a race car, but not so good for the street. for a street car, go with the H pipe and save some money.
  10. Also, usually its easier to fit in an H over an X.
  11. that's with cats, on the ones without cats, the X killed the H
  12. My observation is that it is about even until higher RPMs at which point the X builds only 5 hp more until you get to 5600 when it pulls ahead to about 10 more hp and 10 ft lbs of torque. I don't spend that much time at redline so those benefits to me are only fleeting. The H is cheaper and easier to install and I really doubt that I will miss those few hp I might see at 5600 rpm.
  13. My 2 cents. Any difference between an X and Y will not be something you can feel, especially on the street. Also, The only way to know would to do a dyno test. The results will vary with different combinations, some of which will benefit the H. The other issue is which sounds better to you. I preferr the old school H-pipe rumble. YMMV