I was taking a looking at my stock muffler and noticed a very small crack where the hanger met the muffler. I think I am going to go with the Resonator. It looks like coming off the turbo, it is a 4" pipe that is adapted up to a 5".
I have seen posts where some used 4" and some use 5". I have a 2001 Cummins 8.3.
Any suggestions on sizing? Should I adapt it to a 5" and continue all the way out with 5", or use 4" all the way ?
Also, any preference on brand, Jones, Aero, MagnaFlow??
I have pretty much the same coach and used a 4 to 5"adapter before a Wilson resonator and an happy with it
Simple change over and now have another storage box behind that door for more stuff.
I also removed that body panel to work on change over, simple
Johnh
My answer is what I picked, and why. Only a O-pinion. Everbody got one.
The smallest inside diameter pipe in your exhaust system will be the effective "restriction" regardless where it is positioned.
When we got our coach the exhaust was 4" pipe from turbo to OEM muffler, then a 5" tail pipe (which was not original).
I elected to switch to a MagnaFlow resonator part #12771, which is 4" in and 4" out. Downstream of the resonator, I used adapter to go from 4" to 5" simply so I could retain the existing tail pipe. The 5" tail pipe offers no performance advantage.
I picked MagnaFlow cuz I had used their products on several hot rod cars and liked their signature sound and their quality construction.
Whatever resonator you decide to use, be sure to verify the (smallest) inside diameter (bore). You might find there is little internal size difference between the different inlet/outlet sizes. I know in the case of MagnaFlow, the 4" in/out model and the 5" in/out model both have a 4" core, so there is no point in going to the bigger, more expensive size. This may not be the case for other brands.
Just something to check before you plunk down your cash...
On our last coach(2000 U320) I went with the jones xl, it was about half the price of the aero and from the research I did looked the same
Keith
I put a 5" straight pipe on a 2005 ram 2500 with a 5.9 Cummins. It was the loudest vehicle I have ever owned. It was a higher pitched sound than these bigger engines and the older 5.9s put out. Just a loud drone all of the time. I remember heading to Nevada one year pulling our fifth wheel. We had stopped to get fuel or something and when we started up the on ramp there was a hitchhiker or somebody standing at the side of the road. I mashed the pedal to gain speed to merge onto the interstate and when I looked back in the mirror to see where the person was they were running in the other direction at a high rate of speed with their hands over there ears. It did make me chuckle at the time. I couldn't hardly go anywhere with the back windows down. It wasn't as bad when the truck was empty either. I did eventually put a resonator on it and it made quite a bit of difference. I don't think these bigger engines have that same problem. They get loud I think but it's different.
I need to get a part's list for that system. Someone was selling a Flowmaster setup on classifieds, but so far no response? Looks like a great way to go.
5" 45
5" 90
Short piece of 5" flex pipe ( varies to your application)
4 or 5 band clamps
2 exhaust hangers
Resonator of your choice
I used my old tip so I didn't have to get a new one
Bought the 45*, 90* and flex pipe at a local diesel truck parts business near me The rest I got on amazon
Hope this helps
Keith
I'm interested too, but don't want to order unnecessary parts. How do I approach ordering the correct connectors, bends, hangers necessary for my 2001 U320?
This is new territory for me, and I bet, for others.
Does someone have a parts list?
Is Amazon the " go to."?
Oops. hdff got to it first
If yer gonna do the resonator swap yourself, you need to put your coach up on the safety stands, crawl under the rear end, and take a look at your existing exhaust system. Figure out what will be left after the big OEM muffler is removed. Look at the condition of the left-over pipes and clamps - decide what is reusable and what needs to be replaced. Take some measurements to determine what new components will be required to hook up the resonator. Figure out how you want to "hang" the new resonator and what hanger parts will be needed.
To avoid component stress and reduce transmission of vibration, the exhaust system should not be rigidly hung. Let it move a little!
Each coach might be a little different, depending on how the owner wants to position the new resonator. Different engines present different working space considerations. Older 8.3L GVs are really easy cuz there is basically nothing in your way. Newer coaches are tighter and have some air conditioning components that must be avoided. That's why it is best to research your installation BEFORE you buy the necessary hardware.
Plan your project, take your time, do it right. If you don't mind getting your hands dirty, it can actually be fun! Plus you save $$$.
Resonator (https://www.foreforums.com/index.php?topic=27013.msg219731#msg219731)
Resonator and muffler replacement (https://www.foreforums.com/index.php?topic=15111.msg206944#msg206944)
We used exactly what Keith (hdff) used on our resonator install this Spring. Ordered the 5" resonator and 5" chrome curved exhust pipe on Amazon. I was able to get the pipe bends, hangers, etc at a NAPA store except the flex pipe, which I picked up at a local muffler shop, (used 10"). At NAPA you can bring back for refund what you don't use. AAA card gets you a nice discount. I picked up both a long sweep and short sweep 90* and used the long sweep 90. A die grinder worked great for cutting components. It all went in easy,. As Chuck said, raising coach and blocking the frame gives you plenty of room to work. Was able reuse clamps, hangers. Changed my chrome pipe to a curved tip as the velocity of exhust is much greater without the restrictions, was worried about "blow torching" the Fiat 500 Toad! Just position the curved tip slightly down, or you'll be kiccking up lots of dust if you get on a non paved area.
I created a hanger bar out of 1" X 1" steel angle iron to give the assembly more support, attached it to the top old muffler hanger and bottom to the AC condenser frame. I then installed a heat blanket around the cable/hose bundle that was close to the 5" pipe, used stainless steel ties. Lots of space now! Noticed much less down shifting on hills and, yeah no sneaking out of camp grounds now!
Jeff & Kristen