H Pipe vs X Pipe vs Y Pipe

[GregO]

Which one is your favorite

Y as in,
2 into oval x 2 out.
Look no further than Dr. Gas, Boomtubes or even MRT’s exhaust mid pipe design.

Sponsored

 

[Rapid Red]

How about this? Best of both worlds.

I can honestly say there is a real difference. Between an ad and real world.

Like the pizza on TV, and box of half baked, tomato sauce and cheese in a box....delivered

 

[LSchicago]

How about this? Best of both worlds.

Good in theory, just like the old 180 degree headers, but sound kind of fluttery.

 

[Norm Peterson]

Y as in,
2 into oval x 2 out.
Look no further than Dr. Gas, Boomtubes or even MRT’s exhaust mid pipe design.

What you've done there is build an extended-length X-pipe. I built this over 20 years ago from scratch and a little imagination for a car that was limited to having only a single converter. Turns out that pairs of 2.5" exhaust tubing could be gently massaged to fit into the converter's (flattened) 4" inlet and outlet.

Sounded exactly like an X-pipe running up the rev range, echoing off the Jersey median barriers.

Norm

 

[GregO]

What you've done there is build an extended-length X-pipe.

But without the CFM restriction of the reduced cross-section area. I’m speaking of a true X-pipe and not the sweep bends with the back radius chopped off and welded together.

I’ve only seen X-pipes work as designed on 6 cylinder motors. Personally speaking, an X-Pipe doesn’t belong on a high power high RPM 90 degree fire V-8.
But I understand the X-pipe has its place in the personal preference sound category.

 

[GregO]

Right...that your Internet Professional opinion

Call it what you want.
The information is out there be it Dyno, Books or Web based tech forums.

 

[Mach VII]

No option for double H-pipe?

 

[WildHorse]

No option for double H-pipe?

Why stop there ? put a quad h-pipe. Haha. It's a gimmick. Does nothing but take your money. Same with the double x-pipe.

 

[GregO]

MRT, as close to a double H-pipe Boomtube as it gets and zero CFM loss.

 

[LSchicago]

No need for double H pipes.

No option for double H-pipe?

 

[GregO]

Here we have a Y and a few forum member from the past that posted up how this Magnaflow creation actually yielded faster 1/4 mile times.

 

[GregO]

Post #14 sums it up.
https://www.mustang6g.com/forums/th...-pipe-install-home-built.105486/#post-2278288

 

[WildHorse]

I ask for actual engine benchmarks

Overall, the main difference is sound rather than performance, meaning there are no pros or cons. It's simply a matter of personal preference. X-pipe you lose power downlow, gain up high. H-pipe you gain down low, don't lose/gain anything up high. So in my books that's a wash, all things being equal with the only difference being either a x or h pipe.

 

[FreePenguin]

I dont see how exhaust makes a difference, as long as there's no restriction, the shit goes whereever.

magic

 

[Norm Peterson]

But without the CFM restriction of the reduced cross-section area. I’m speaking of a true X-pipe and not the sweep bends with the back radius chopped off and welded together.

I get what you're saying, and for that, the details will matter. Fortunately, exhaust flow is a series of pulses, so the left and right banks aren't going to be at peak flow at the same time. Even if they did, you'd only effectively need about 40% more pipe diameter in the merged section.

FWIW, the catalytic converter in my other post was rated to flow 600 cfm at about 1 psi pressure drop. Or only about a 2.5% or so loss of peak power and smaller sacrifices in torque everywhere below that.

I’ve only seen X-pipes work as designed on 6 cylinder motors.

You would still get the benefit from essentially putting the mufflers in parallel for less pressure drop. But . . .

Personally speaking, an X-Pipe doesn’t belong on a high power high RPM 90 degree V-8.

On a 90° V8 with a flat-plane crankshaft and proper header design, maybe not (though the mufflers in parallel matter would still be present). Think 3.0 liter Cosworth DFV here, not the recent GT350 here.

With a crossplane crank, the firing orders for 90° V8 engines put two cylinders in the same bank firing in sequence, first on one side, and later on the other. This dumps a combined flow from two cylinders down each pipe, in side to side alternating fashion. This is where your classic V8 rumble is coming from. But this also means you get periods of somewhat higher backpressure some of the time. An X-pipe merges the flows and splits them more equally going rearward to the mufflers, whose resistance is also dependent on exhaust gas flow.

I got pretty deep into this. Here's a rough approximation of how it plots up. The big widely spaced peaks are your low-frequency V8 rumble, and the red trace is what a fully merging X-pipe (or pair of Y's, your choice) would end up giving you. The smoother, higher frequency appearance of the X-trace is obvious.

But I understand the X-pipe has its place in the personal preference sound category.

I'm not discounting that at all. I was more than pleasantly surprised at how my effort above turned out.


Norm

Sponsored