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All "H" pipe VS "X" pipe questions

52K views 73 replies 44 participants last post by  marcus410 
#1 ·
All of the cars shows I watch anymore show them putting on exhaust systems with an X-pipe. Is the X-pipe that much better than the H-pipe?

Has anyone had a H-pipe and changed nothing else, but went to an X-pipe?

I am running 2 1/4" exhaust with Flowmasters, would changing to an X-pipe help reduce the resonate noise coming up through the floor? (my exhaust runs all the way out to the rear bumper)
 
#3 ·
Someone did some research on "X-Pipe" vs "H-Pipe" vs no crossover and tested the results with different size pipes and mufflers etc. I think it was a Pontiac related project but should apply to anything. I think the difference was significant between "X" and "H" pipes.
 
#5 ·
72Orange said:
Someone did some research on "X-Pipe" vs "H-Pipe" vs no crossover and tested the results with different size pipes and mufflers etc. I think it was a Pontiac related project but should apply to anything. I think the difference was significant between "X" and "H" pipes.
Here's the article 72 is referring to. Reading this is what caused me to put an X-pipe system on my car vs. an H-pipe system. It looks like it's worth about 1/10th in the quarter on this guys test.

http://www.pontiacstreetperformance.com/psp/exhaust.html
 
#6 ·
I ran an H pipe on my Nova back in the seventies. It improved torque but really changed the tone of the exhaust. The X pipe configuration has replaced the H pipe design. If you want that true dual exhaust sound then don't put either on.
 
#7 ·
Paul Wright said:
I ran an H pipe on my Nova back in the seventies. It improved torque but really changed the tone of the exhaust. The X pipe configuration has replaced the H pipe design. If you want that true dual exhaust sound then don't put either on.
One thing I've noticed, and also heard from discussions around here and other sites on the net, is that my X-pipe system has a different sound from most of the other cars I hear at the shows. It's very smooth at the tailpipe and not horribly loud. This could be due to my muffler choice also, but it doesn't have the classic dual exhaust note to it. It's perfect for what I wanted hear out of my car. :) At speed it's kinda fun too. :D
 
#8 ·
A tech article in one of the recent National Dragsters stated that stockers and super stockers are starting to use X pipes more due to torque gains over headers and torque tubes.
 
#9 · (Edited)
NovatoriusRex said:
One thing I've noticed, and also heard from discussions around here and other sites on the net, is that my X-pipe system has a different sound from most of the other cars I hear at the shows. It's very smooth at the tailpipe and not horribly loud. This could be due to my muffler choice also, but it doesn't have the classic dual exhaust note to it. It's perfect for what I wanted hear out of my car. :) At speed it's kinda fun too. :D

I agree totally with the above. I put an X on my dual exhaust, the idle mellowed out big time, at cruising speed the sound also lowered dramatically, also felt a minor, yet positive, improvement in seat of the pants feel. Couldn't believe the difference made with all things being equal, with the exception of the added X pipe.

The theory behind it is, the X pipe tricks the system into thinking its larger than it is, hence improved flow and performance.

If someone is looking for more internet info to back up these claims, here is one I found using a brand F car. :)


http://carcraft.com/techarticles/69238/
 
#10 ·
Unusual X-Pipe

I was just wandering if anyone had seen this X-pipe design before. These guys seem to have come up with a slick way to build their own in-house. I found it interesting.

http://www.customexhaustsystems.com/
 
#12 ·
If I were in Texas, I would probably have to pay these guys a visit about doing some work. I like their way of thinking.
 
#16 ·
I know this get asked all the time. BUT other then the obvious visual differences between the two types of balance tubes what is the difference? Does one of them work better for a street car while the other works better on a drag car/race car? Is one better for torque? Why would you choose one style over the other? Also how do they both effect the sound of the car?

Thanks in advance:)
 
#18 ·
I've had both on my BB. For me it came down to sound. The X pipe had a higher pitched Indy car sound and the H pipe had a lower muscular rumble to it, which I personally like better, so I chose the H pipe. I've read that the X pipe is suppose to be a little better in overall performance gain. Personal preference I guess :) .
 
#20 · (Edited)
Mike Goble said:
Thats very interesting reading Mike...I guess the "X" pipe is the way to go but the link itself says that either crossover style is useful its just that the "X" style gave addition improvements over the "H" style. For those that dont want to read the link here is the general findings from the link

By Jim Hand & Tom Hand said:
1. Always use a crossover of one kind or another. Our tests indicate that the X type gives additional improvements over the H type.

2. Mount the mufflers as far to the rear of the chassis as possible. An important characteristic of the exhaust system (behind the headers) is its ability to dissipate heat energy. Heat loss brings with it, gas volume reduction, enabling smaller mufflers and pipes to be used without penalty.

3. Always us the largest case muffler that you can fit under the chassis possible. The larger internal volume allows additional acoustical energy to be absorbed ,dissipated and eliminated.

4. Unless an engine is in the 500+ horsepower level or run at very high RPM, the maximum tailpipe size required for minimal power loss is probably 2.5" diameter. When the exhaust pipes and mufflers drop the temperature significantly, the volume of the exhaust gas is reduced and tailpipe sizes is not as critical.

5. When you must adapt various pipe sizes, always use long tapered cone reducers, such as, those available from Flowmaster. You can also use a crossover that has reduced pipe sizes built into it.
Now its interesting that their findings for a muffler is very simular to the findings poster by other member in another thread:

Colin said:
Dawg Im in Marion, about halfway between Hickory and Asheville.
Flowmaster 40 series 2 chamber flows 60% of what an open 2.5" pipe will flow.
Dynomax Ultra-flo flows 93%
Dynomax welded Ultra-flo flows 100%
Magnaflows are 83% for the 14" long and 85% for the 18" long.
I dont have any info on the Flomaster super 40 series.
Sound levels at 3500 rpm(with a big cubic inch engine) in same order as above:
98dB
91dB
93dB
94,95dB
A crossover pipe(x-pipe) will usually lower the sound level a little depending on rpm range.
All tests were done using a large displacement(454+cubic inch) engine.
Goerlichs Xlerators flow nicely too at 94 and 97% ;)
So I guess Flowmaster isnt the master after all.
Just as a refference a popular brand OEM mufler flows 53%
Stay away from the Magnaflow baffled mufflers though they dont flow as well......but still flow better than the Flowmasters.
Good to know info:)
 
#23 ·
The way I read the article, a 3" x pipe going into my 2 1/4 stainless exhaust is the way to go(i don't want to buy another $600 exhaust just to upgrade to 3" all the way) am I right ???
 
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