This is a great method of modifying the stock exhaust system on a 2000 4.7L Dakota (not rated for California emissions). The power and sound is a definite improvement over stock. The first time I modified the exhaust, I had some exhaust clangs, but this method of modifications has absolutely no clangs. (Even when intentionally driven over hard bumps to challenge the effectiveness of the exhaust hanging method.)

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You will need the following parts to match my exhaust setup:

1 Dynomax Super Turbo Muffler - (NAPA Part #17748)

1 2.5" 90 Degree Mandrel Elbow - (NAPA or online through JC Whitney)

1 Exhaust Hanger (See Photo of Hanger in Instructions Below)

2 2.5" Stainless Steel 2.5" Exhaust Band Clamps - (NAPA or online through Summit Racing)

1 U-Bolt Style 2.5" Exhaust Clamp - (NAPA Part #733-5337)

You will need the following tools (or similar) to assemble an exhaust setup like mine:

(Dewalt) Reciprocating Saw

Reciprocating Saw Blades

Socket Set or Wrench Set (Primarily, but not limited to 1/2", 9/16", or 13mm and 14mm sizes)

Mallet / Hammer (You'll see why, nothing needs to be forced.)

Vice

One of the first choices you will need to make is whether or not you want your Dakota for street use, or off road use only. There are certain muffler designs that are not legal for street use, and there are many that are. The closer you get to an illegal muffler, the more power gain you will will see (usually) and the louder your vehicle will get. I am not going to get into the details of backpressure creating harmonic resonance, thereby resulting in improved power. For the sake of simplicity, I shall talk in terms of power gain being directly proportional to backpressure.

Since the Dakota is not a vehicle I am interested in modifying heavily at this point in time, I chose to use a conservative muffler. Major plans for the Dakota remain 5-7 years out. Therefore, you will not find many high performance modifications on my site for the Dakota. I went to my local NAPA store to browse through various Dynomax muffler products that were reasonably priced and that would offer the power gain/noise level that I wanted. You can also purchase Dynomax products from organizations like Summit Racing.

This is the muffler I purchased at NAPA. The reason why I chose this muffler is because it would be quiet while providing much better flow than the stock muffler. It was also under $60 after sales tax. I wasn't looking for a full on race muffler. While the thought did cross my mind, I did not want to attract the attention of our friendly Washington State Law Enforcement officials who don't like loud vehicles. I have friends who have been pulled over multiple times due to the noise level of their exhaust. (Even though their vehicles were street legal, and under the legal limit for noise level per Washington law when tested with decibel meters.) That is why I wanted quiet performance, which is exactly what this muffler provided. In addition to power, this modification should also improve fuel economy.

The markings on the muffler give you a rough idea of how exhaust gases pass through the piping. All of the piping is perforated so that exhaust gases can evenly pressurize the entire muffler. This helps to avoid unnecessary travel through the muffler passages if gases are being expelled at a rate greater than that of exhaust gases at the input of the muffler. The dashed lines represent the perforated exhaust passages. There is actually a little more space between the perforated lines than shown. The curved lines at the ends of the exhaust passages represent the curved brackets that are welded into place at the end of the exhaust passages to help direct the flow of exhaust gases.

Placing the muffler in the exhaust stream of your Dakota is totally dependant on the dimensions of the muffler you choose. For the purpose of keeping this simple, I will use the dimensions from my truck as if you chose the same muffler that I did. If you did not choose the same setup that I did, then you will need to modify the placement of the cuts you make on the stock exhaust system. Standard exhaust clamps and band clamps were both used. I recommend the use of band clamps for connections that contain exhaust flow (if you intend to use this exhaust for a long time). Band clamps like the ones sold at Summit Racing can be purchased at your local NAPA auto parts store.

Now that you have the parts, it's time to make some cuts on the stock exhaust system. I recommend the use of Dewalt blades over that of Milwaukee or Blu-Mol. The Dewalt blades far outlast the other brands when it comes to exhaust work. For my exhaust setup, I made a cut in the stock exhaust system approximately 13.5" laterally (in a horizontal plane) downstream of the stock exhaust joint held together by a U-bolt clamp with grounding strap. From this point downstream to the tailpipe, all stock exhaust componentry should be removed through the use of a reciprocating saw and/or the appropriate tools.

The next step of the exhaust modification is to slide a 2.5" band clamp over the stock exhaust pipe that is remaining. Then slide the inlet of the Dynomax muffler over the outlet of the stock exhaust. Secure this coupling with the 2.5" band clamp as shown in the above photo. The next step will be to attach the 90 degree elbow to the outlet of the muffler using another 2.5" band clamp as shown in the photo below. Be sure to route the outlet of the 90 degree elbow slightly downward and toward the passenger side of the vehicle.

I purchased the single exhaust hanger at my local Schucks/Checker/Kragen auto supply store. However, I would like to note that:

I try to avoid buying anything from them because the people who work there seem to only understand carbureted engines rather than fuel injected engines. Another reason is that if you intend to modify your vehicle, the employees don't seem to understand or even have the slightest bit of creativity in their heads so you can't tell them what you're doing. Otherwise, they'll question why your modifying your truck with various items while you could be putting a 4" lift kit on it like they do to their rusted trucks parked outside in the parking lot.

Now, back to instructions for the exhaust modification. The single point hanging system depicted below is pretty self explanatory. The exact instructions are to remove bolt in the frame rail that is connected to the next piece of frame toward the back of the truck. Only remove the nut and bolt shown holding the exhaust hanger in the photo below. Do not remove both nuts and bolts. Doing so could be problematic, and it's not necessary.

Notice how I have made a bend in my exhaust hanger that lines up with the horizontal edge of my frame rail. I did this by lining up the first hole in the metal exhaust hanger with the bolt hole and marking a line on the hanger that lined up with the edge of the frame rail. Then I placed the hanger in a vice in a manner that would be conducive to bending along the line I had marked. I used a rubber mallet to make a bend of about 45 degrees in the exhaust hanger as shown above. Then I placed a 2.5" U-bolt style exhaust clamp on the 90 degree elbow attached to the outlet of the Dynomax muffler and attached the clip on the hanger to the 2.5" U-bolt style clamp and 90 degree exhaust elbow as shown in the photo below:

As you can see, the hanging setup controls lateral as well as vertical movement. It works very well, and I hear no exhaust clangs. -Even when I'm trying to make them. I've also noticed that as a result of this modification that fixed driving conditions that I experience on a sometimes daily basis no longer require me to downshift as they did previously. Therefore, I know something positive in terms of power and fuel economy came from my efforts.

Send Questions, Comments, or Suggestions to Craig Grass.

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