I installed [the Dynomax kit] about two weeks ago (ordered from Allpar). It came with the little adapter needed to fit it onto the existing pipe. HOWEVER, I have to suggest welding it on instead of clamping. I used the supplied clamps, and I just couldn't get it tight enough that way. Just this morning I took it to the muffler shop and they welded it for me. That also got rid of an annoying whistling noise it was making at certain low rpms (due to a leak at the clamp, I'm sure). I have no complaints about the sound now. It's very slightly louder and deeper than stock.
Getting the old pipe off can be a chore, especially if you don't have the right tools. I cut and pried and banged until I finally got it. There's a picture of the damage I did at http://188.8.131.52/sundance/air.htm.
Also, FWIW, I put some audio of my Sundance with NO muffler at http://184.108.40.206/sundance/results.htm.
if you all are changing your exhaust systems out here's an idea for you all: use Walker stainless clamps instead of horse shoe clamps. This way you can disassemble the exhaust system easy if you need to. The clamp wraps around the outside of the muffler so it doesn't actually crimp it. Might be a little bit of a looser fit, but I like it for the prospect of being able to swap mufflers easy. I've got 'em on my car. Available in different sizes from summit (800) 230-3030. Oh and that reminds me: if you're going to change out the old muffler get a Dremel type tool to cut off the old horseshoe clamp and old muffler. The stock clamp on there crimps the muffler to the midpipe so there's NO way that you'll yank it off. Be careful when cutting not to damage the midpipe unless you want to buy a new one! Here's how to cut it:
Wear safety goggles and mask over your nose and mouth when doing this. If at all possible cover your entire face (ski mask?) and any exposed portions of your body. Bits of metal from the muffler plus bits from the disintegrating cutting head fly off at a high rate of speed. I was pulling things out of my skin for days after I changed my muffler.
DISCLAIMER: This is what I did when I changed my muffler and it worked, I make no guarantees for you. Instructions are for educational use only and not guaranteed to be proper or in compliance with anything. I'm not a Mopar tech and have no affliations with Chrysler. Bottom line: don't sue me or Allpar if you try this and something goes poof, falls off and gets wrecked, etc.
Crank the Dremel device up to max speed.
Cut off the piece of the muffler that's about 4 inches from the clamp (towards the back of the car) so that the muffler can be used (SAVE THE OLD MUFFLER!)
Then to get off the piece of the muffler that's still on the midpipe you need to make 2 horizontal cuts (one on each side at about the same height).
It'd be best to start from the front and work the way to the rear so you can see the proper depth that the cutter blade should go. Lightly apply pressure with the cutter to the metal (remember the muffler and midpipe overlap) You'll know when you've reached the midpipe (it's obvious).
Now once the old muffler has been entirely removed get the trapese assembly (for lack of a better term) that suspended the old muffler off the old muffler without damaging it. For ones with a screw holding it on (heard these exist) removal is self explanatory. For ones with a bolt holding it on (my old one) use the Dremel to cut off the fat part of the bolt.
I found that the screw provided by Chrysler (yes, I bought one for $2.50) doesn't work for the Dynomax. I made a substitute by using a screw just big enough to get through the Dynomax's hole and then stepped it up to fit the hole of the trapese assembly using washers. PAY ATTENTION TO WHAT YOU USE TO HOLD THE SCREW TO THE MUFFLER!
In other words: use lock washers, drill a hole in the screw and use a cotter pin, etc. to make sure this doesn't come undone. I put mine on last October, driven it hard with lots of vibration, and haven't even had it screw budge so I'm pretty certian that if proper caution (and common sense) are used to the screw then you'll have many miles of worry free driving. Now you can pitch that old muffler.
Now a little note from experience: The superturbo that I put on mine had one little problem with it: the muffler was shorter than the rear end of the car and put out so much bass that it made it sound like a carpet bombing raid was occurring in the cabin when I started going. Of course I did do something stupid (well two things). Mistake number 1: I probably should've used that little piece of pipe enclosed in the kit to point the exhaust downward instead of leaving it off (this would've probably directed the sound waves safely to the ground). Mistake number 2: not being that smart at that time I stuffed a pipe slightly smaller than 2 1/2 in it and attached a Monza 4" big bore attachment (2 1/2 intake side, 4" outake) with resonator. Only problem is that the pipe was as long as the last chamber of the muffler. Translation: I'm not using the muffler’s capacity correctly, leaving my little EEK with it's 2.5 4 banger sounding louder than a Ferrari in heat at only 3k rpm (really screaming later on). Not seeing the error of my ways early enough, I left the pipe in there too long and it's pretty much soldered in there with no hope of coming out (ever).
Hope this doc provides some guidance/laughs for everybody that's going to buy the Dynomax. Despite all my mistakes I still like the muffler a lot and the performance difference was noticeable from day 1. Just my two cents.
Trenton’s 7 and 15 millionth enginesMilestones in 440 and slant-six form
Texas MoparfestBig Mopar show in the Lone Star state
This page is in-image-ad-free, 50% of the time. Support Allpar by using our Amazon link
All Mopar Car and Truck News
Killing the buzzes
Dodge pickup trucks, 1961-71