"H-pipe," X-pipe," or no pipe?

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FISHBREATH

FISHBREATH

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I know that the factory "H-pipes" were a great improvement over separate dual exhaust pipes. New data seem to indicate that "X-pipes" are an improvement over "H-pipes." However, are these pipes of any benefit over headers with only open headers and mufflers? Do they provide benefit only with full exhaust systems?

Am I correct in noting that Super Stock cars run with "open" headers with only an extension pipe and no crossover pipe?

The reason I ask is that I plan to use header mufflers and side exhaust on my '68 'Cuda.
 
Waking up an old thread with no answer. Anybody have any experience with crossovers on open exhaust?
 
Larry Sheppard Mopars' head racing engineer says an H pipe provides no increase in power but will make your exhaust quieter.This allowed the factories to install less restrictive mufflers back in the day.
me...i don't know.
 
According to a friend who designs this stuff, the X-pipe eliminates the turbulence problems associated with H-pipes. They both equalize pressure between left and right banks.
 
I have an x-pipe system from DR GAS (with 30" boomtubes..similar to NASCAR). I am REALLY happy with this Exhaust system. They have dyno tested their systems and it quiets your system down 12-15 decibles with zero HP loss when compared to open headers. It cost me about $900 for the parts, and $250 in labor to pay someone to weld it and install it. It sounds SICK! Check out these pictures and videos. Send me a private message if you want to talk off line about it. You can hear my car with open headers and after the exhaust has been installed (skip to the middle of the video) at [ame="https://www.youtube.com/watch?v=cDkwrmhScIk"]1965 Plymouth Barracuda tribute car: Pat Clark - YouTube[/ame] and here is similar system on a 65 chevelle at [ame="https://www.youtube.com/watch?v=pYRzU6OLefs"]Dr. Gas Boom Tube Muffler Exhaust Build for 65 Chevelle - YouTube[/ame]

here is their website http://www.drgas.com/xpipes & http://www.drgas.com/Boom-Tube-Muffler_p_32.html (I went to their factory in Salt Lake, met with the owner, saw them being built). What quiets the sound down are the half circles welded into the chambers...very cool). You will have to paint them and cut them to whatever angle you want if coming out the sides, or leave them alone if going straight out the back).
 
Open crossover vs open exhaust. You're probably not going to see a whole lot of difference in power between the two. In the sound department? Open headers sound WAY better than does the open X pipe. It's one of those things that you have to hear in person to understand how much of a difference it is.
 
I bought the Dr. Gas X pipe also on the recommendation of someone who is way smarter than myself on exhaust systems. It cost me 3X what I could have bought one from Summit for, but my expert says that it's worth it. Dr. Gas has done extensive research in designing high flow/low restriction exhaust systems.
 
I cant say if the x pipe i have on my Dart improves it's performance, but i can say it sounds really really good with the x pipe, compared to a previous car with a similar exhaust system but without a x pipe.
 
I have had the same Dr. Gas x pipe (3" in / 2.5" out) on my last two big block cars for the last 15 years.I love it and think their design is true compared to a lot of the cheap copies out there in terms of flow and sound.
It also creates a scavenging effect helping to pull the exhaust out(I am no engineer but that is what the claim is).
On your setup it will quite the exhaust versus without it.It will also raise the pitch of the exhaust note as well.
Run what fits easily if space is tight.
 
Had the x pipe on the Scamp, sounds like a frickn mustang to me. Left it off when I upgraded to the stroker.
 
Bought the TTI system in 99, with dual 3inch pipes, Dynomaxers, and their simple H-pipe crossover. Drove it for 4 years or so. Had to sacrifice it when I put the GearVendor in it.It seemed like I lost a ton of torque.From right off idle to maybe 2400 or so rpm. But it sounded better, to me, out the TP.I put 4.30s in/problem solved. 4.30 x .78 = 3.35 final-drive. That was fun for a summer or two. Then, eventually, I put 3.55s back there. 4.30s suck with a 3.09 low, on the street;(4.3 x 3.09= 13.29starter gear. Sounds like a doggone Mustang 5 spd. Sheesh)
Sorry, I digress. I vote crossover. Any kind. Whatever your budget allows. Extra torque,off-idle, is always welcome in a streeter.
 
I've mentioned this before in another thread. I read this in a car mag or article somewhere a long while ago. They did a dyno test between the three. No crossover, X pipe, and H pipe. I don't remember numbers, but the X pipe made more peak power, and the H pipe made more torque over the X pipe. When I built my own H pipe I could definitely tell a difference on the low end and it sounded better and quieter in my opinion.
 
x-pipes will make slightly more horsepower, but you can split an H-pipe so it's easier to work on the trans...
 
I spoke with Doug Thorley hisself many years ago about this. He told me that all of they dyno and drag strip testing they ever did showed no appreciable gains from any kind of cross over pipe. Be it H, X or whatever. He also said (and I agree with him) that any kind of cross over takes away some of the crispness of dual exhaust.

I think for something on the street, you 'd not notice a power difference one way or the other, but the sound certainly does change with a cross over.......and IMO not in a good way.
 
RustyRatRod said:
I spoke with Doug Thorley hisself many years ago about this. He told me that all of they dyno and drag strip testing they ever did showed no appreciable gains from any kind of cross over pipe. Be it H, X or whatever. He also said (and I agree with him) that any kind of cross over takes away some of the crispness of dual exhaust.

I think for something on the street, you 'd not notice a power difference one way or the other, but the sound certainly does change with a cross over.......and IMO not in a good way.
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agree w/ rusty, straight duals w/ collector size pipe make more power, but, more noise.
 
No pipe , sounds better , at least I think so . Factories added H pipe to cut noise down
 
i have a hard time believing a 6 inch piece of pipe can make any power.
...but i've been wrong before.
 
I've battle tested open headers, x-pipe open and x-pipe with mufflers. X-pipe with Flow 30s ran the same ET as open X, and both were quicker than open headers. I have also seen other guys get a significant power increase from those extension pipes, but I've never tried them.
 
gumper said:
I've battle tested open headers, x-pipe open and x-pipe with mufflers. X-pipe with Flow 30s ran the same ET as open X, and both were quicker than open headers. I have also seen other guys get a significant power increase from those extension pipes, but I've never tried them.
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It would be cool if you could post some specifics of the differences (et/mph) between the systems. I assume the car under test is the Duster with a 408? Thanks.
 
6pkScamp said:
Had the x pipe on the Scamp, sounds like a frickn mustang to me. Left it off when I upgraded to the stroker.
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You say that like a it's a bad thing. If it sounds that smooth, then I'm sold!

I'm actually planning on going the X-pipe route, but I don't know if I want to get the Summit brand or the Pypes brand to go along with my Doug's headers. I kinda decided on the Summit brand welded Flowmaster knock-off mufflers. Or, I might use the Magnaflows I have but I don't like how they sound.

There's also a local muffler guy that makes them that comes to the Long Beach (CA) High Performance Swap Meet often who I plan to check out soon since my engine will be ready by next week.
 
Demon 408 said:
It would be cool if you could post some specifics of the differences (et/mph) between the systems. I assume the car under test is the Duster with a 408? Thanks.
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Yes, the Duster with the 408 about 7 years ago. Several parts have changed since then (fuel system, ignition, torque converter....), but the homemade exhaust is the same. Time slips are long gone, but I remember the testing on a Friday night at the 1/8 mile track. It ran 8.15 open, 8.04 with the x-pipe and 8.05 with the mufflers. The exhaust goes 3" collectors, 3" pipes, x-pipe, mufflers and dumps before the axle. Was pretty simple to swap the pipes on in the pits after the first run, and the mufflers are clamped on. I figured the x-pipe would help due to reading many other dyno tests proving their worth, but the mufflers surprised me. They don't cost any power, so may as well keep my hearing somewhat good by using them over open pipes.
 
JoesEdge said:
You say that like a it's a bad thing. If it sounds that smooth, then I'm sold!

I'm actually planning on going the X-pipe route, but I don't know if I want to get the Summit brand or the Pypes brand to go along with my Doug's headers. I kinda decided on the Summit brand welded Flowmaster knock-off mufflers. Or, I might use the Magnaflows I have but I don't like how they sound.

There's also a local muffler guy that makes them that comes to the Long Beach (CA) High Performance Swap Meet often who I plan to check out soon since my engine will be ready by next week.
Click to expand...

Honestly, does it or not sound like a stang? If thats what you want your car to sound like than so be it. Been there done that, over it.
 
JoesEdge said:
You say that like a it's a bad thing. If it sounds that smooth, then I'm sold!

I'm actually planning on going the X-pipe route, but I don't know if I want to get the Summit brand or the Pypes brand to go along with my Doug's headers. I kinda decided on the Summit brand welded Flowmaster knock-off mufflers. Or, I might use the Magnaflows I have but I don't like how they sound.

There's also a local muffler guy that makes them that comes to the Long Beach (CA) High Performance Swap Meet often who I plan to check out soon since my engine will be ready by next week.
Click to expand...

I used the Summit X pipe on the stock 5.2 with the Hedman shorty headers and a 2.5" mandrel bent custom exhaust with the Summit dual exhaust kit with the turbo mufflers...I don't think it sounds like a Mustang at all. It sounds like a smooth running stock small block V8 through a generic exhaust system with a crossover. Truthfully speaking, I'm pleased with the way it sounds.
 
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