My 'Selecable' Muffler Install (w/ Pics)
 

I decided it was time I 'straightened' out my exhaust a little bit. . . . . From past experience with the mighty Cummins and a 'straight' through muffler that was too loud for pulling, I was a little hesitant to just completely straighten out the exhaust on my Mega. I bought one of those Rokk Tech mufflers and when I saw the inside of it I couldn't help but come up with the idea of making a slide to put inside it so I could have both a muffler in one position and completely bypass it in another. I started off wanting to take the OEM system apart intact so if I ever had to 'replace' anything it would make it a lot easier than if I had just cut it out of there. Another aspect of doing it this way is if you do a mod like this and don't like how it turns out, it is easier to change it down the road. (My last Cummins had a straight through muffler and you couldn't tow above 70 mph without it splitting your head!!)

My professor suggested using a clamp design to pull the factory pipes apart. I feel fortunate in that they didn't over tighten the u-bolt clamps on my exhaust. I had pulled those clamps off right away when I got the truck. Here is a pic of the clamp I made to pull the joints apart:

Attachment 45191

It really did work quite well!! Only place I had trouble using it was for the tail pipe right behind the muffler. That is a little tight since the tail pipe has a resonator in it right in front of the rear axle. Two rigs, some chain and a come-a-long will also pull this joint apart! Here is a pic of the inside of the OEM resonator:

Attachment 45192

This is what the inside of the new muffler looks like. This is the only openings in it at all! They are roughly 2 inches square ea and right near the end of the muffler. The instructions say to install it with these at the rear:

Attachment 45193

This is a shot of the 'slide' I made to go inside the muffler. It basically covers the openings in the muffler making it a straight pipe. When I want a muffler again I use the 'handle' to slide it forward and expose the openings inside the muffler. I use the muffler for towing heavy. It takes the drone out of the cab and makes for a pleasurable trip!

Attachment 45194

Here is another that shows how I ran the handle through the tail pipe to be able to move the slide inside the muffler:

Attachment 45195

Another part of this install that I really like is the wide band clamps that I used to hold it all together. These are just like what big rigs use and I recommend them. It only takes a couple of minutes to connect a joint in the exhaust. It comes apart just as fast! If you have any doubt of whether you will like a muffler or not; this is the way to go!! This is also a very good thing to have in case you have to 're-install' anything in your exhaust for certain 'agencies' if you know what I mean. Here is a pic of one of these clamps (Notice the red arrow pointing out my 'handle' to be able to select which mode of muffler I want!):

Attachment 45196

Hope this helps. If you have any questions or ideas, just let me know! :tu:

Looks interesting, smooth and easy to operate? Those Torq-Tite clamp are awesome, used one yesterday.
I have always thought about a 2 position valve that would either direct the exhaust through a muffler, or just dump it off. Never came to life, but I'm pretty sure it's possible.

I have always wanted to have some kind of cutout valve in the exhaust of most of my rigs... Just never got it done. This seems to be a good system!
It is easy to operate. In fact, I need to find a way to keep it from moving back into the 'bypass' mode. I tried tightening a wire around the outside of the pipe to keep the handle from moving back but that didn't work. I need to come up with a fastener or latch of some kind.

Where did you get the muffler from?

From:

Rokk Tech

But, they have listed the muffler as 'Out of Stock' for some time now. I don't know why or if they will ever have them again.

The Donaldson muffler is supposed to be the same thing. The one I purchased from Rokk Tech was a 48" one.

Just the other day I removed my OEM tail pipe which had the resonator welded into it and replaced it with a different one without a resonator. I can't believe how much the resonator was doing for me. It is so much louder now. Sounds a lot like a tractor now! Turns out 'straighter' is better! Course I have to tow with it to see if I can stand it. I hope to do that soon. We will see. :pca1:

Hmmm I checked them out they seem like a pretty good idea. I may have to contact them and see if I could get one in a 5" and run a setup like you have. I want to run a stack and want it to be LOUD when I want it to be, but would like to also be able to set it to where its quiet for long trips.

Re: My 'Selecable' Muffler Install (w/ Pics)
 

Very nice!! Ferraris and lambos do that. Except they have a switch on the steering wheel.

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i was thinking about just buying a cheap cable operated exhaust cut out. i think i can pick one up for about 60 bucks. have one side strait piped and then the other side muffled. just my 2cents

looks good!!! i agree with RAwilliams...those torktite clamps are awesome!!!

What Donaldson muffler do you mean? :pca1: