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Hi everybody ! I'm looking for a complete exhaust system for my 67 convert. with has a 302-2V. Actually, it's a simple exhaust and I want to put it double. What is the best choice between an H-PIPE or an X-PIPE system ?

Thanks for your opinion,
Dan
 

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I think that the X pipe will give you faster throttle response. Cost a bit more but that is what the exhaust dude told me when I put a new system on.
 

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The H-pipe is a lot easier to configure or install. The original dual exhausts were always equipped with an H-pipe. Here's a 66 Shelby:

 

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I think they both do the same thing... the X-pipe might do it better because of the velocity moving through. I could see the H-pipe letting some by that the X would catch, just based on the direction of the flow. The pressure on the low side of the H would have to be lower than the velocity is high on the firing side to pull it over (because of the 90 degree turn it would have to make). I'm not explaining this well at all and just sound like a tard. Nevermind.
 

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I think they both do the same thing... the X-pipe might do it better because of the velocity moving through. I could see the H-pipe letting some by that the X would catch, just based on the direction of the flow. The pressure on the low side of the H would have to be lower than the velocity is high on the firing side to pull it over (because of the 90 degree turn it would have to make). I'm not explaining this well at all and just sound like a tard. Nevermind.
Well, the function is not for the H to carry actual flow, it evens out the "pulse" of each cylinder as it hits the system. This way, each pulse hits both mufflers, creating less back pressure, and deeper, mellower sound.
 

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Discussion Starter #7
The H-pipe is a lot easier to configure or install. The original dual exhausts were always equipped with an H-pipe. Here's a 66 Shelby:

So, the H is cheaper and easier to install, but the X is better for the sound and the efficiency ?
 

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I was as usual thinking to hard into it. I knew the function was to equalize pressure, and was overthinking the equalization with the flow dynamics of the moving gasses.
 

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Well, the function is not for the H to carry actual flow, it evens out the "pulse" of each cylinder as it hits the system. This way, each pulse hits both mufflers, creating less back pressure, and deeper, mellower sound.
++

When you think about it, there may be some power difference between the two of them, but it would be like 1/8 HP or something. In other words, far too minor to worry about. My own intuition tells me that the H is probably better though I couldn't define why if asked.
 

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I prefer the deeper tone from an H-pipe. It just sounds tougher.
 

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Oddly enough, for best power, neither may be right without substantial testing.

I had a friend...who was a well known racer sponsored by Flowmaster. They did substantial back to back testing of straight pipes, x pipes, and h pipes. They baselined the engine, and ran the straight pipes. Then they began testing by moving the crossover incrementally until they got the best ET. Rinse and repeat for each type crossover. The x was slightly faster, with the h coming in second...but ONLY when they were within 2" of optimum placement, which had nothing to do with the color of the exhaust or anything else the tuning myths tell you to use to place them. In any other configuration they lost acceleration to the straight pipes by a large margin.

And guess what happened when they changed the carb tuning and advanced the cam?

The optimum placement moved around substantially.

So in the end, for a street/strip car that isn't looking for the last tenth...but wants the best power with the least work, just run the straight pipes (I do). For a street only guy who wants a specific exhaust tone, choose by sound quality. The only guy that should be worried about X or H or straight, is the guy who is searching for every last ounce of acceleration at the track.

Here's an example of what my daily driver sounds like with 3.5" straight pipes and four dynomax race bullet mufflers, dumped before the axle:

RLYSLOW - 67 Mustang Coupe Startup and Walkaround - Car Videos on StreetFire

Cris
 

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ChrisAnderson, that car sounds SWEET! But further to the original post, I'll need to make the same decision shortly. I've noted that the aftermarket systems that incorporate "x-pipes" state that they will NOT fit convertibles. But in searching this same topic I read that some folk have been able to fit a "universal" x-pipe in their verts. I'd very much appreciate a pic from anyone who has done this.
 

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ChrisAnderson, that car sounds SWEET! But further to the original post, I'll need to make the same decision shortly. I've noted that the aftermarket systems that incorporate "x-pipes" state that they will NOT fit convertibles. But in searching this same topic I read that some folk have been able to fit a "universal" x-pipe in their verts. I'd very much appreciate a pic from anyone who has done this.
Thank you!

Just for the record, Summit sells all the pipe bends AND the crossover fitting to build your own x pipe...at very reasonable prices. If I had any issues with noise violations with the coupe, I was going to install a 3.5" x pipe to tone down the exhaust a bit more. I'm sure that one could use these fittings to install one in a convertible.

Just a thought.

Cris
 

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The convertible problem is there's very little space forward of the center plate to install the more bulky X pipe.
 

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I read this thread with interest as I too will need to choose in the future.

Frank, I LMAO, at your politically incorrect comment!

I'm not explaining this well at all and just sound like a tard. Nevermind.
To the OP...good question:thumbsup:
H will work for me.
 

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As mentioned already, there is definitely a sound difference, the H-pipe will be a little bit lower of a tone, and a have a bit more rumble. the x-pipe will have a smoother idle and have a bit more of a 'racier' or modern sound.

There is certainly a noticeable difference in sound for the same car with both styles back to back. Don't worry about the performance difference between the two you won't notice. Just decide what kind of sound you are going for and pick that way.
 

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Heres mine with tri-y's, universal summit x-pipe, and Spintech mufflers.. Stops right behind the mufflers, haven't got tail pipes yet.. You can hear the volume a lot more when the camera is looking at the back of the car.

I definitely think X-pipes sound better.

 

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No one mentioned exhaust scavenging, primary benefit. The issue is that every engine and combo may need a different placement of the crossover to really do much. Due to turbulence and other things, the location is also affected by what rpm you want the gains at.

Old school I use to run a crayon along the inner edge of both pipes. Run the car at the rpm where you want the gains. Find the most melted or burned off spot of crayon (hopefully somewhat aligned but never perfectly) and put the H here. This worked, dyno proven. However, doing an x this way would prove most difficult. I would think equal length primaries would be a must for an x pipe to be ideally located. I have also always thought that the silly old SBF firing order with sequential 7 and 8 on the same bank cant be ideal, not just for crank forces but for exhaust pulses.
 

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Several years ago I was looking to upgrade the exhaust system on my 96GT. The prevailing thinking on the message boards at the time was that an H pipe performed better at lower RPMs and thus provided better torque numbers, whereas the X did better at higher RPMs and increased available HP. At the time a popular swap was the Bassini X which I had installed on the car and still works great today.

About two years ago I ran into a guy from Magnaflow. Magnaflow is based in Orange County, CA. and attends the bigger car shows around here. The rep said that the X is always better and that the rumor of H impacting torque better than the X was false.

Take it for what it’s worth…to my eyes, it seems like an X would be better at equalizing the pulses as there is no 90 bend. I don't, however, have experience with airflows at cyclinder exhaust velocities so i can only offer an opinion.
 

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Had an H but switched to an X to quiet the car so the next door neighbor wouldn't complain about the noise. Had Dynomax Super Turbos with the H and went to Hooker straight through Max Flows with the X. The X even with the straight through mufflers is definitely quieter and stopped the complaints. The H sounds better though. The X sounds too weird. Would go back to the H if it weren't for the neighbor............

 
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