X-pipe vs. H-pipe

[Pac-man]

If the X-pipe is supposed to work better than the H-pipe, does anyone know why GM used the H-pipe in the C5? I think the cost would be about the same but maybe I'm missing something. Any input is appreciated as I am considering adding the X. Thanks in advance.

 

[MsSchroder]

Why are you considering changing it? Are you having any problems?
I've heard that the notorious pennies-in-a-can sound on Z06's can be solved by getting the X-pipe.

Tammy

 

[Bioscache2]

I could tell you from a fluid mechanics perspective why the X-pipe is better but I could only guess at GM's decison to use the H-pipe. If pressed I would say the straight pipes were easier to produce then the curved X-pipes. But thats only a shot in the dark.

 

[Remo]

Diesel,

Here's another guess. First the H-pipe design has been around for many years and GM might have the "if it ain't broke don't fix it" mentality. Secondly, the stock exhaust system is so quiet that the need to smooth out the flow (eliminate popping and gurgling) was a non issue.

On the other hand, I recently installed a Borla Stinger exhaust system and found the popping sounds on decleration to be something I didn't like. As a result I replaced the GM H-Pipe with a Corsa X-Pipe. It smoothed out the exhaust flow and eliminated that "motor boat" popping.

Now on the subject of which offers better performance. There have been many threads on the CAC as well as studies done by various Corvette magazines on this subject. Most parties agree that there is "some" performance improvements using an X-Pipe but nothing like the claims by the vendors.

Remo:cool

 

[Pac-man]

Thank you for the answers, but one question remains. Will the addition of the X enhance the sound of the Stingers or mellow it out? Has anyone added the X after a catback system was installed previosly? Don't really care about 5hp. Looking for a bada$$ sound.

 

[jrose7004]

I think that the X-Pipe will mellow out the sound!

 

[Ken]

It's an ongoing discussion that appears to have no end: Google search for "X-pipe vs. H-pipe". Have fun - there's lots of reading.

 

[David Gordon]

I have TPIS headers MTI X-pipe and then down the line the factory H-pipe. So i have both, I wander if this is costing me any power.
I JUST ADDED THE fAST 90MM INTAKE and TPIS throttle body and dynoed 486 rwhp and 448 rwtq. fyi that is from my last dyno of 485 rwhp and 466 rwtq so my tuning may be a little off. But still back to the exhast has anyone ever tried running the x and h pipe both?

 

[Ken]

... has anyone ever tried running the x and h pipe both?

What would be the point? :confused

 

[David Gordon]

No point its just what I have.

 

[Ken]

I wouldn't think it'd hurt anything; it'd simply be more difficult to work around. Plus, it would just be an unnecessary expense.

As for the differences between an X-pipe and an H-pipe ...

For any performance exhaust system, some type of crossover connecting the two sides of a dual exhaust system is important because it acts to balance the two banks of the engine. The common H-style crossover is good at balancing sound pulses between the two halves, but does little to promote scavenging because the exhaust gases tend to follow the path of least resistance - straight through each pipe rather than taking the 90° turn through the H-pipe into the other half of the system.

In an X-pipe system, however, where the two sides of the system intersect, the gasses have no choice but to intermingle as they pass through the junction. This promotes improved scavenging effects by smoothing out uneven exhaust pulses from the engine’s firing order. It also helps quiet down the exhaust, resulting in a mellower, less raspy tone. The faster acceleration of the gasses through an X-pipe causes them to flow in a linear fashion parallel to the walls of the tubing rather than tumbling. This laminar flow of gas is much quieter than tumbling gas, resulting in an exhaust tone that is somewhat quieter than a traditional H-pipe.

 

[Patrick]

The faster acceleration of the gasses through an X-pipe causes them to flow in a linear fashion parallel to the walls of the tubing rather than tumbling. This laminar flow of gas is much quieter than tumbling gas, resulting in an exhaust tone that is somewhat quieter than a traditional H-pipe.

Exactly why I have no intention of changing out my H-pipe. I got my Corvette precisely because of the meaty, aggressive exhaust note. A sports car ought to sound like a sports car, and every X-pipe I've heard just doesn't sound as aggressive as I'd like. As I said, that's only a personal preference.


-Patrick

 

[Ken]

... every X-pipe I've heard just doesn't sound as aggressive as I'd like.

You haven't heard mine yet, Patrick. :L

 

[Larry's Yellow Rdstr]

X pipe better?

Not quite on the subject but it deals with the choice between the X and H pipe on a Chev V8.. I built a 383 stroker motor for my El Camino (white fang). The guy doing the final tune and dyno work strongly suggests we use the X pipe rather than the H pipe. He feels there will be a slight increase of usable HP with the X. White Fang has long headers into flowmasters and is too too LOUD!

This thing couldn't sneak up on a logging truck.

Keep the wave.

 

[Ken]

This thing couldn't sneak up on a logging truck.

But we like it that way, right?

 

[hcolon]

Ok, guys, let's see if I can chime in here a bit. I recently changed my entire exhaust sytem with a Supermaxx by Dynatech. this sytem is compromised of LT headers, high flow cats, x-pipe(crossover pipe) to Corsa Indy's. The sound is unbelivable! However, there is quite a bit of backfire, popping on deceleration. I am not too crazy about the popping either, but I was told that the high flow cats are the reason. Hope this helps.....
herbie

 

[hcolon]

I have TPIS headers MTI X-pipe and then down the line the factory H-pipe. So i have both, I wander if this is costing me any power.
I JUST ADDED THE fAST 90MM INTAKE and TPIS throttle body and dynoed 486 rwhp and 448 rwtq. fyi that is from my last dyno of 485 rwhp and 466 rwtq so my tuning may be a little off. But still back to the exhast has anyone ever tried running the x and h pipe both?

Hey Dave! 485 rwhp, with just headers, x-pipe , h pipe and a fast manifold and 90 mm TB? On a coupe? What else is on your car??
Herbie

 

[David Gordon]

That would be good for exhast and intake huh. I forgot the extra cubic inches.

 

[hcolon]

Sorry, what extra cubes? Never really heard of a coupe pushing that much juice with intake & exhaust, that's why. Just curious.
Herbie