71 M code X pipe, H pipe or neither

[Milalynne]

On my 85 mustang I always had an exhaust shop build and installed a H pipe to go along with my long tube headers and flow masters.
Well my 71 has just exhaust manifolds which im replacing with long tube hedders and having them ceramic dipped by the guy that did the ones for my 91 corvette. I like the H pipes but everything I read that the X pipe is better maybe only a little but still better and I will have to buy them already built, anyone used a x pipe on their car before and if so, what are your thoughts and did you like the sound of them?

 

[Steve McMahan]

Maybe these guys can offer some advise:

 

[giantpune]

There are too many variables to make a broad statement like H pipe or X pipe will always add power. If you could say that, then you would see people running X pipes on all their dyno runs to milk out every last horsie power.

Personally, I go with neither. Just straight duals all the way to the back. That lets you play with the transmission and driveshaft without having to take your exhaust apart. It still makes a nice vroom vroom sound.

 

[Sheriff41]

I've had both on my '72; H-pipe with stock manifolds and X-pipe with long tube headers. I prefer the sound of the H-pipe and will eventually replace the X-pipe. It's purely a personal preference thing, though.

 

[72conv]

A simple H-pipe will sound good and will help to balance the exhaust pressure between the two sides. I have one on my car.

 

[California 72]

Can attest to the “H” pipe interference with the transmission. As I was removing mine recently because I couldn’t pull both assembled due to space, the tail of my FMX hung up and it sat for a couple weeks teetering on the converter and “H” pipe.
One other thing of note, being a convertible, there’s that really necessary flex plate straddling the shaft tunnel that the exhaust is also routed thru.
While it is being held up quite wel just behind the “H”, it’s when I reinstall the motor with long tubes attached where I’m concerned. Not exactly sure how everything will line up for making modifications without removing the plate and system. Especially in a home garage.

 

[rcadd1ct]

I went fpa long tubes, X pipe and hooked max flows with turn downs

All 3” as that is what I had from squirreling parts away.

 

[Barrysmach1]

I am having exhaust done on 72 Mach 1 with Booker long tube headers ,I am going with H pipe but we are making it removable , I like sound of h pipe over x

 

[RIBS]

It really boils down to what sound you want. Slight rasp with X, slight rumble with H. The performance gains of each are so minor it probably completely indistinguishable in everyday driving.

 

[c9zx]

How often are you at 6500 RPM and looking for an extra 3-5 HP? The H sounds better everywhere. Divorced duals sounds like an old man farting in a bath tub after drinking way too much beer. Do what you want. Chuck

 

[turtle5353]

 

[turtle5353]

I like x pipe. This is the one I had installed on the yellow Mach 1 I did.

 

[Tnfastbk]

I have had both. The X pipe is a lot quieter for sure. I was shocked by how much. The exhaust shop said think of it this way as far as sound. X pipe = Indy car/exotic car. H pipe = Nascar/muscle car. That being said I will be going back to the H pipe if I ever change my exhaust again

 

[Cleveland Crush]

How often are you at 6500 RPM and looking for an extra 3-5 HP? The H sounds better everywhere. Divorced duals sounds like an old man farting in a bath tub after drinking way too much beer. Do what you want. Chuck

Who the hell doesn't love the sound of a drunk old man farting in the bath tub !!!???

 

[BigBlue]

I've had both on the same exact setup, and as others have said, I'm on the h-pipe camp.
You won't notice any power difference, and whatever little horsepower difference there is, you can count on one hand. So don't let that be a deciding factor.
The h-pipe has a deeper, throatier sound, especially on the higher revs. The x-pipe has a raspier, more "exotic" sound. Sounds appealing on writing, but it's not. At the upper end of the rev range it just sounds weird. I switched to h-pipe a few months ago, despite the muffler shop guys trying to talk me out of it, and didn't look back. It was the right decision. Makes it sound more like a proper muscle car.
Granted, I have a 302, so maybe an x-pipe sounds better with a 351, but comparing both on my setup, there's zero contest IMO.

 

[tony-muscle]

H pipe and 12" collector extensions work great. The extensions should help to improve your bottom end torque. There is another Engine Master episode that goes through this.

 

[mjlan]

H-pipe is a more tradiational sound, X-pipe will sound like a late model V8.

I like x pipe. This is the one I had installed on the yellow Mach 1 I did.

@turtle5353 whoever installed your exhast did anawesome job. Kit or custom?

 

[turtle5353]

H-pipe is a more tradiational sound, X-pipe will sound like a late model V8.


@turtle5353 whoever installed your exhast did anawesome job. Kit or custom?

Local shop did mine and this one. They do great work. Around $650-700 for everything from headers back. E&E exhaust in Mercer PA.

 

[mach71351c]

H pipe with cut outs so it doesn't matter. LOL

 

[mrgmhale]

After doing a lot of reading online and watching the Engine Masters episode where they covered the H vs X pipe question, in our 73 Mach 1 I opted to go with an X-pipe because I wanted to remove some of the audible harshness I would otherwise get. The X-pioe worked perfectly. I have had balance (H) exhaust plumbing in the past. It is better than nothing.