H-pipe vs X-pipe? 3

[Latexman]

Is sound quality, and thus marketing, the big difference? Does one create less backpressure than the other at the same flow? Or, does one affect scavenging more than the other?

Good luck,
Latexman

 

[IceStationZebra]

I don't have any hands-on experience but the "testing" done by Hotrod and the like have shown a slight improvement in power with the X design. My intuition agrees with this as the H design requires the gases to make a sharp 90deg turn, which should decrease the effective RPM range where the crossover helps. And this is not a scavenging effect so much as a decrease in back pressure and frequency tuning. ISZ

 

[FoMoCoMoFo]

with exhaust systems the one that works best with the engine is the hardest to fit in the chassis. can you say axiomatic ?

 

[patprimmer]

You mean like fitting a 180 deg exhaust to a V8 with a cuneiform crank. ;-)

Regards

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Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[ShawnR]

The "O" Pipe is far superior to the X and especially the H pipe. Link =

http://kalecoauto.com/index.php?main_page=product_info&products_id=3

 

[Rob45]

The 'H'-pipe is primarily used for sound quality, and I doubt there was ever any significant amount of flow through it.
The discussion of its effect is better suited to the acoustics forum; it is located based on acoustic wave behavior in the pipes.

 

[Latexman]

I doubt there was ever any significant amount of flow through it.

I agree. Because of this, one would reason that the H-pipe would put less backpressure on the motor. If this is so, why does an X-pipe consistently have slightly better HP and torque than an H-pipe in the magazines IceStationZebra and I have read? That's a dilema I don't understand.

Good luck,
Latexman

 

[patprimmer]

Data in magazines is not always representative and accurate.

Editors sometimes seem to give extra support to products of advertisers in their magazines

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[kenre]

I have to get a couple of O pipes!! there the answer to all my exhausting problems, I cannot fit either an X or H crossover pipe to my project. only a left and a right hand system on a V8.... but it looks nice in stainless.

Question, does anyone think there will be any tuning issues??

http://www.retallickeng.com.au

Was told it couldnt be done, so
i went and did it!

 

[Latexman]

Yes, the pressure to produce profits is mighty, but what about those that just want the most bang for the buck, like

http://www.pontiacstreetperformance.com/psp/exhaust.html

Good luck,
Latexman

 

[Kriegen]

H-pipes are an old car trick to keep the flow pressures equalized. It didn't really help the sound difference much at all but is the cheapest exhaust mod. The X-pipe is another pressure balancer but in this case the higher flowrate helps "suckout" the opposite which frees up piston power. Usually the X-pipe only increases hp by 10% but every little bit helps.

 

[patprimmer]

10% increase, boy that must really suck.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SomptingGuy]

I really enjoy the hand-waving discussions that take place here. "suckout" (sic) has got to be one of the best single words used to describe tuning effects.

 

[PackardV8]

Am surprised by the restraint shown by all our professionals who absolutely, positively know empirically there is no way a X-pipe can produce a 10% net horsepower increase on a street-driven, street-legal exhaust over similarly sized twin isolated pipes or H-pipes.

Again, the sound effects belong to the acoustics forum, but empirical experience has proven over and over, an H-pipe will attenuate many resonances found in twin isolated exhaust systems. If sufficiently large and properly placed, it may show some very slight horsepower advantage, but its OEM use has always been for acoustic control.

For many years, GM preferred to place a second "resonator" muffler at the end of their dual exhaust system, instead of using the H-pipe favored by Ford. Problem was, these resonators, being at the end of the exhaust, seldom warmed sufficiently to vaporize condensate. Thus, they rusted out regularly.

thnx, jv

 

[FoMoCoMoFo]

I understood Patprimmers post to be a comment on the 10% claim. I'm still waiting for a single exhaust craze to sweep the performance automotive world. happy motoring

 

[Tmoose]

On my pals' 1962-1966 Chevy Impalas (Impalae) I think the "resonator" was the forward muffler in each branch.
Their removal added a bunch of noise at full throttle.

 

[patprimmer]

The post was so obviously wrong, I expect no professionals thought it worth their time to give a serious reply.

4:1 single exhaust works fine on a 4 cylinder or even better, 3:1 works great on a 3 cylinder. I'm sure that craze if alive and well in motor cycle circles.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[AboveRedline]

If you have a nasty cam and a single plane intake manifold a crossover pipe (H) can pick up a lot of mid-range torque. It tends to fill in the hole in the torque curve. I didn't think it was ever about top end horsepower or exhaust flow, it probably looks more like adding collector volume in the model.

 

[bentwings1]

I just talked to Flowmaster Muffler co. about some mufflers. The guy told me to be sure to add a cross pipe (H pipe or X pipe whatever you want to call it). The sole purpose was to create the "right sound" IE deep rumble for streetrods. Otherwise he says no performance gain at all with or without it. Put it where ever you want as long as it is in fromt of the mufflers. It apparently alters the mix of sound waves to make a more "pleasing" sound. Gotta admit that if you are a gearhead, their mufflers sound great.

As for the 10% increase. I think way back when this was first introduced someone added the 10% better sound effect and someone else interpreted it to mean 10% hp gain. haha

Never seen any gain or loss in hp.

99 Dodge CTD dually.

 

[strokersix]

I prefer the sound of two independent exhaust systems on American v8 engines. One such system is factory style headpipes into Flowm***er mufflers, then over the axle to custom built resonators exiting under the rear bumper. I've built resonators using perforated stainless tubing as the core surrounded by glass and cases cut from glasspack mufflers. Works great!