Well I've been thinking about this.

1) Stock muffler does not show any restriction (unless in the hidden third pipe).

2) Aero does not seem to be any peppier with the Dynomax.

3) Dynomax seems to sound like a beater from inside van (does have nice throaty roar outside when you rev engine). Think fiberglass matting fuzzes the sound.

3) Object was to fix hole in pipe. Easy to replace muffler because hole was at hangar which was 2 inches from muffler body.

4) I figured out how to reinstall old muffler and eliminate holed pipe at same time.

So, I probably will put the old muffler back on, since it is too much hassle to add a resonator and hope it is quieter. Will try to return muffler. I know Dynomax has gaurentee if you are not satisfied. Or save it for someday when I get a Ranger 4 banger or something like that.

 

a chopped fiberglass packed muffler only gets louder with miles.

Ford used anti resonance technology in the OEM stock muffler with interior tubes and baffles

aluminized on steel last close to what a stainless steel muff. does.. the top line in Walker Quiet Flow is in this class

 

The "stock" muffler is a replacement. OEM muffler went out maybe in 4 years. Replacement lasted 2 years. Then I went to a different shop and this muffler has been on since about '98. The problem is the pipe was rotted through around the weld where the hanger attached.

Usually with only a couple inches of stub on the muffler you can't reconnect easily because the inside pipe is permanently welded in by rust. But I figured out my extra 2.25 OD pipe from my F150 exhaust project slips over the flange nicely, so I will clamp a piece on, then use a 2.25 ID to 2.00 ID reducer to get to the stock pipe.

I figure, there is no need for loudness unless there is power gain. Only thing, I can't see the third tube inside the muffler. On the F150 factory muffler that third tube was 1.75" ID on a system with 2.25" OD piping. That muffler was a big plug. But in this case it does not seem so. I would like to check out that third tube, but hate to drill a hole in the end plate to look in (can measure with coat hanger bent on end), because I would have to plug it with a big lag screw. But maybe worth it to know.

As for the Dynomax, I don't know if I like the fiberglass packing. They say it will take something like 1600 F, but I also think it gives it a sound, interiorwise anyway, like a rag over the pipe. Outside, if you blipped the throttle in neutral, it gave a nice growl, but overall, my Raptor (which has no packing) sounds a lot better.

Live and learn, so they say. Anyway, I don't mind the floor time. It's fun working on the Aero and it is not in vain as I am acheiving something, that is, the rotted pipe will be replaced and it will be good to go for a few more years.

I'm going to look up the work order and see if they stated what kind of muffler.

 

blew out the chopped fiberglass in dual "cherry bomb" style glass packs on a Chev. BB 454ci PU towing in Yellowstone years ago.
rangers made me park it because it was LOUD, shook the bears out of the trees.
closest muffler shop auto parts store 50 miles away and they didn't make deliveries

packed 'em with steel wool and wired the ends to hold the steel wool in, drove it home. lasted several more years until I replaced them with real truck mufflers
quiet as a mouse

 

Did you mean to say "quiet as a moose"?

 

Well, now I know I can't put that OEM type muffler back on the Aerostar. The 2" piping in the exhaust system has a 2.75 square inch internal cross section. I bored a couple holes in the end of the OEM type muffler that I pulled off and discovered that there is no third tube. Instead of a third tube there twelve holes, each 3/8 inch diameter. That figures to about 1.32 square inches cross section--A 50 PERCENT BLOCKAGE!!!!!!!

 

Well, now I know I can't put that OEM type muffler back on the Aerostar. The 2" piping in the exhaust system has a 2.75 square inch internal cross section. I bored a couple holes in the end of the OEM type muffler that I pulled off and discovered that there is no third tube. Instead of a third tube there twelve holes, each 3/8 inch diameter. That figures to about 1.32 square inches cross section--A 50 PERCENT BLOCKAGE!!!!!!!

Thankfully, my wife is relatively indifferent about the sound of the Dynomax. She doesn't like it but her dislike is not enough to have me back under the van. Hopefully she will just live with it and the Aero will be better off.

 

the top line in Walker uses a 3 tube noise reduction design

that 454 BB Chev actually towed better with those blown out "Cherry Bombs" DIYer'd with steel wool plugs. needed the back pressure to improve the torque response

 

Dynomax is made by Walker and is a three tube design.

 

Yeah, I did notice a power increase with the Fullblown Muffler on my van, but then again I have the 4.0L. TallPaul already expressed that my van would be too loud for his wife, so that idea was killed. If the Dynomax is what you and your wife are happy with, stick with it. You can't mess with satisfaction.

And yes, the performance mufflers are better, but how much better depends on a variety of conditions. My system is 2.25" from the catback which is a good size for the 4.0L. So some of the improvement probably came from enlarging the pipe as well as replacing the factory muffler. I do not really recommend just replacing your factory muffler with a performance muffler unless you need a new muffler anyway.

 

the Dynomax Super Turbo is a 3 tube noise cancelling design w aluminized case
http://www.dynomax.com/products/superturbo.html

the DMax Ultra Flow is a single tube design with far less noise reduction
http://www.dynomax.com/products/ultrafloweld.html

the fiberglass in both designs mats down from cold startup moisture and burns out over time causing a noise increase

too rich for my blood
i stick with the standard Walker 3 tube, all steel, no glass, aluminized

turn down the volume for the last one
http://www.dynomax.com/sounds/flash/sounds.html

had a ski boat years ago with a Berkley pump, 455 Olds, 6-71 blower and straight headers
the riders in the back seats had to wear hearing protectors, keep their bare legs away from the red hot headers and their hair out of the supercharger intake
used about 2 gallons per mile of leaded 105 octane

 

Pretty sure your Walker is going to me more restrictive. Walker's are generally OEM type mufflers.

I could have gotten a cheaper muffler in the Raptor with no glass.

 

if i were concerned about max. flow, i would just run a straight pipe from the flex out the back end to clear the pass. compartment with exhaust noise and fumes

here's what I run
http://www.walkerexhaust.com/products/mufflers_quietflow.asp
not much restriction in that

not going to see much performance improvement from free flow muffler on these small V6s until the rpm is above 4k rpm
the crossover, cats and flex pipe add more backpressure than the stock OEM muffler

 

96, you beat me to it.

You know, we might be straining at gnats here. These vans aren't hi-po machines, but they run pretty well.

All I've noticed with muffler replacements was a little more smoothness and better throttle response, but nothing earth shaking. The cats would be the choke point, and this van has 2 of them inline. I'm not ready to spring for a hi-flow cat and y pipe replacement just to gain an increase that might not be worth the money invested.

I say keep it legal, keep the noise to a low rumble, and enjoy the obvious dependability of the van.

The first replacement muffler was a generic Thrush turbo muffler, just a regular oval model. I had to replace the flex coupler and it was a good time to put something else on it. After I put that one on, I noticed better throttle response and it ran a little smoother. Noise increase was noticeable, but negligible from an annoyance perspective.

That one lasted for a few years and then it rusted out like all things in the salt belt. The flex coupler was giving up the ghost again and the muffler was rusting out on the front seam. The tailpipe, at 125k, was finally ready for replacement.

So I went to Advance, asked for a new tailpipe and a glasspack close to the same length as the OEM muffler, and walked out for a little over 60 bucks, clamps and all. I had to get the flex coupler from NAPA, and it cost me 60. Made in China, GGGRRRRRR, but it was in stock and ready to install.

If the glasspack blows out, it blows out. I can almost run with a straight pipe out of the cats and live with it, but it won't be legal. I think the cats really do help with the noise, and they have to be there, anyway.

I'm no big fan of glasspacks and loud exhaust, but I am a big fan of saving money on auto repairs, as long as they are done properly. Once I grew up (maybe I haven't yet, you'll have to ask my kids) I never felt that a vehicle had to make a lot of noise to run well. Too many fart cans, and I'm ready to stab myself in the face with a fork.

That's why they make aftermarket stereo head units and hi-watt amplifiers. Forget those booming woofers, just put together a well balanced system. My kids tell ME to turn it down, but they're still surprised how well I can hear them talking in the other room.

 

i never could understand the music listening thrill of these boomer box Honda Samari kids with their 10 giga watt sub basement 42 inch woofer

the windows flex in and out and the car moves with the bass thumps

i would never subject my next car over driver neighbor to Shostakovich's Drums of War

nothing like the sound of a SB Chev with a big cam turning 6k in 2nd gear and the rpm dropoff crackle in the exhaust as we go to 3rd