Switching from a 2 1/2" system with H pipe to a 3" with an X.

[Kern Dog]

I've read that the X pipe systems give you additional torque over an H pipe system. I have also heard that the X  gives a more refined sound.
Currently I have a 493 with 2" TTI headers and Flowmaster mufflers. I am likely to keep my 2 1/2" tailpipes even though I want to use a 3" intermediate section. The types of X sections are varied. This one is the cheapest I've found:

http://www.summitracing.com/parts/jex-xp6/overview/

[Kern Dog]

Not that I'm hung up on going the cheapest route. This design looks more refined but would it deliver a different sound and power level ?

http://www.autoanything.com/exhausts-mufflers/69A2672A0A0.aspx

[cdr]

the cheap one looks fine,it would be better with 3in tails,but good luck finding them

[cdr]

this is the magna flo set up on my junk

[tsmithae]

There are a couple people that offer the 3" tails - I have a pair.  I think they are offered by Year one, TTI, Herb's, and probably a couple others.

[fy469rtse]

CDR , it's not junk, it might have seemed that way at the start, but at your threads ? Look at how many guys like yourself are looking on I awe at what you can do yourself,
Cars come along way since you picked it up, it's in good hands
I have a look at everything you do
3" tail pipes yes had to make my own, I put 20" inch red back hotdogs where the straight section leading up to tips , this will hopefully get rid of that resonance these get at a certain speed,

[RallyeMike]

Summit makes complete kits with 3" tail pipes. Buy their x pipe conversion and bash them together.

[bill440rt]

I might be wrong, but thought I read you were toying with the idea of a GV unit, or may already have one?
From what I understand the X-pipe won't clear a GV unit. Something to consider if you're planning on installing and OD setup. 

[cdr]

I might be wrong, but thought I read you were toying with the idea of a GV unit, or may already have one?
From what I understand the X-pipe won't clear a GV unit. Something to consider if you're planning on installing and OD setup. 

OP has a gear vender,mine is a518 odrive

[c00nhunterjoe]

I have the summit 3" kit on mine. Had to slightly modify for the left header/collector hookup. I think they are bent for hooker super comps and i have heddmans. Otherwise it was a perfect fit. No issues with clearance or fitmant. I love it.

[Kern Dog]

I do have a Gear Vendors in there but there is still plenty of room to fit an X in place. The kit from TTI claims to NOT fit a GV equipped car probably because they first fabbed the system on a 727 and 833 car and didn't think of any other possibilities. The GV means that the X needs to be a bit closer to the headers which makes the pipe bends slightly different. I wish I could use the TTI mandrel bent kit to further less restriction. Muffler shop bends always result in reduced flow. Anyhow I figure that 3" pipes with compression bends are still better than 2 1/2" pipes done the same way.

[Cooter]

Whatever kit you do run, be sure and use band clamps. I can have the whole system out in 15 min.

[cdr]

Whatever kit you do run, be sure and use band clamps. I can have the whole system out in 15 min.

yep 

[Kern Dog]

Currently I have 3 bolt flanges at the collectors and at the inlets of the mufflers. This allows me to remove the center section of the exhaust in 1 piece. I might have the X pipe system done the same way.

[bill440rt]

I remember BananaDan having problems with his X-pipe when installing the GV. It needed some mods to make it work, it did not "fit". Not sure if he's running 2-1/2" or 3" pipes, though.
TTI claims an H-pipe will fit no problem.

[c00nhunterjoe]

When we are modifying 40 year old cars from stock and mix matching components, i dont expect many things to be a direct fit.

[bill440rt]

Isn't that the truth! 

[Cooter]

When we are modifying 40 year old cars from stock and mix matching components, i dont expect many things to be a direct fit.

That there is about the best post yet.

[Kern Dog]

I'm used to having to "massage" everything with this car. Why make things easy on myself now?
I put in my own H pipe last month. The stories I hear is that an X pipe reduces the cackle and instead has a higher pitched sound. It is also supposed to add torque. The Ultra Flo mufflers are supposed to outflow the Flowmaster mufflers while being quieter. This to me seems like a good way to go.
Has anyone heer made a similar change?

[bill440rt]

Funny you should ask...
My '68 has Flowmasters with an H-pipe. The '69 has Ultra-Flows with an X-pipe. Both cars have 2-1/2" systems however, from TTI.

Flowmasters are definitely louder & aggressive, I had to add resonators out back after years of dealing with the drone. This made no change at idle, but took care of the annoying drone while driving.
The Ultra-Flows with the X have a real nice tone, quieter but still aggressive, no drone either. I MUCH prefer this setup. 

[Kern Dog]

I ordered an X pipe kit from Summit, 3" MagnaFlow "Tru-X" and 3" Dynomax Welded Ultra Flo mufflers. I mocked up the kit.
The placement of the X isn't decided yet. If I place it in front of the gv unit, the exits from the header collectors is a bit sharper than I'd like. I doubt that it is a good idea to place it directly below theGV unit itself since the heat may cook the thin oil in the unit. I'm likely going to just place the X centered under the end of the unit at the output shaft. This may not be optimal for power but it may be the best I'll be able to do.
With the Flowmasters, the inlets face each other toward the driveshaft. To fit the X in place, I'll have to put the inlets opposed so the pipes are spaced further apart. I doubt that this would be a problem as long as the exhaust enters the inlet.

[Kern Dog]

I ended up placing the X centered just below the front yoke of the driveshaft.
The old system was cut out with a Sawzall and set aside. I had to cut all 4 pipes to get it all to fit, then I tack welded everything in several spots. The tailpipes were a pisser since they are 2 1/2" and the muffler inlet/outlets are 3". I cut slits in the muffler outlets and bent the "tabs" in to meet the tailpipes. My welding skills are not great. I'm fine at overhead work but it is the sideways and upside down welds that are difficult to do. The metal wants to "drip" away from the pipes. I called a buddy for advice. He said to increase wire speed and weld in "pulses" when doing anything other than welding from overhead. I'll have to try that. I need a better welding helmet too. My cheap POS is too dark and I have trouble seeing what I am working on. I may buy another helmet next week.
The center section was unbolted to allow me to do better welds on it from overhead. The car is on jackstands with limited room to work and move.
I may have to have the tailpipe welds redone after all is finished but I think the main section will be fine after I "tune up" the welds with a grinder. I know that you're not supposed to grind on welds but some of the joints are sloppy looking. My skills are not pretty but I've never had anything fall apart or crack.
I'm anxious to crank it up and hear it run. I hope to have it done tomorrow.

[Cooter]

  I've found with anything other than 3/16" plate, it's better to stack up alot of  .  Spot welds rather than one long bead.
yes, welding upside down sucks!

[Kern Dog]

This sucker sounds great. It is hard to describe what a change like this "sounds" like, but I like it. It is quieter at idle. Quieter at cruise speed too. I can't tell if it is any faster or not. It does sound great under power though.

[deepockets]

how about sound video and picts?