Foretravel Owners' Forum

I decided it was time to do a few things in the muffler bay area.  I had not re sealed that section of beltline yet and I realy didn't want to do it ( tailpipe ) laying on my back ( stuff falling in the face and all that ).

  Going to start towing something soon and decided to loose the muffler for an extra horse or two.

  The glue holding the filon ( if that's how to spell it ) to the floor had come loose, I suppose from the heat.

  Our S hose storage is there and there is room for 2 storage tubes.

  Just clean, ospho any light rust, prime and re paint while I'm in there.

  Bonus...  I found two hydro hoses that had been rubbing together and eventually would have worn a hole in one of them.

I'm watching with interest. I'm wondering what the noise level increase is running down the road. Looks like a straight pipe makes sense .

I Like!  ^.^d  I did my resonator install lying on my back in our driveway - stuff falling in face.  Your way looks much more pleasant.

I doubt you will hear much sound difference in the driver seat going down the road.  Standing at the rear of coach when it's idling will be louder, but surely no worse than those Dodge dually diesel pickups that wake you up at 05:00 in the morning (discussed in a recent thread).

Nice project and good photo report!

Rollin' Coal!!
Nice job.

I also replaced my muffler with a straightpipe. Not because I wanted more power, but because I wanted my exhaust to exit behind the RV, not into the engine bay. My muffler was rusted apart into swiss cheese.

louder going down the road? yes.
loud when standing behind the RV? triple yes.
leaving a campsite at 5AM? absolutely not.
the most awesome upgrade performed? YES.

I love the sound. The turbo spooling up and down as load changes on cruise control is absolutely amazing to hear. My bedroom floor is still warm, my mattress is still hot in the summer, but the entire rear end is no longer covered in soot after a trip and my motorcycle stays clean on the rack behind me. I'll never modify it with a muffler or resonator.

First mile test drive down the road and back.  Little loader at idle and going down the road ( with windows down ).      But taking off and acceleration,  oh ya. Definitely hear the turbo spooling up and down.    I like it.

Bob, I would think about wrapping the muffler or some type of heat shield depending on how close the exhaust pipe is to that PVC. would probably do it anyway just to reduce some of the heat. Still, a nice job!

Unbelievable, I did the same thing two weeks ago! lol  :thumbsup:

Cuure,
 
It looks like you increased your exhaust pipe from 4" to 5" after your engine unit did its thing.
 
Is there really a benefit to using the larger pipe after leaving the engine exhaust system?
 
I am not sure whether my output is 4" of 5". My thought process has been to use a 4" resonator if it already 4" and a 5" resonator if it is already 5". Now you guys are making wonder if I really need a resonator.
 
Decisions, decisions, decisions.
 
Trent

I did the 4 to 5 inch piping just for the sound. About the performance, I could not really tell a difference. Maybe faster spool up time on the turbo. About the piping diameter, what really chokes the exhaust is the diameter on the turbo down pipe.

We visit a lot of National Parks here in the west and with the varied topography with it's ups and downs, a coach with a straight pipe or short resonator is not going to be the most popular with fellow campers. I can imagine what we would sound like with a straight pipe and the Jake in operation. Our high altitude with noise and smoke from our generator got a knock on our door from an incensed tent camper before we went solar. Getting good campsites in summer at parks like Yellowstone mean early departures to the next campground. While "the morning hour has gold in it's mouth" is usually true, many campgrounds mix RVs with tent campers and the sound of a heralding trumpet in the early morning hours does not make many friends.

Pierce

Pierce.
 Would you be using your jake in a campground ??     
 With the short time that I have driven it ( 3 miles or so ) it seems the idling noise level has gone up a little but not much.  I have also noticed that at 750 / 800 rpm idle speed, I don't need much extra throttle going thru a rv park.    And increased throttle doesn't change a lot either.  No more than a 500 hp 45' pusher.

 Where I expect the big difference in noise to be is under acceleration, merging traffic and climbing the PNW hills.  And in those conditions who cares. Might wake up some other "distracted" drivers also ( short of using the Hadley's). 

 Give me a couple hundred miles and my opinion could change completely :)

 rbark.  I will be wrapping the pipe with heat tape nearest the hoses today as a precaution and installing a longer heat shield too.

No. Can't imagine many using the Jake in a campground but in parks like Yellowstone, there are many turnouts for attractions that are on roads with a gradient. Not only are Jakes rude but climbing past the turnouts is also rude with an open pipe. The turbo does take a bit out of the noise but it's still loud. I've run several cars with turbos without mufflers and from the outside, the noise was offensive. Big rigs are offensive enough but when they use the Jake, it really adds to the noise. That's why many places have signs posting no Jake brake.

I still remember hiking on a nice peaceful trail when the quiet was spoiled by a few bikes a mile or so away. While some of us may watch our carbon footprint, it's nice to have a low noise level footprint too.

Pierce

Think a resonator is the best compromise. Gets rid of the 55 gal heat sink muffler, frees up space on most coaches, saves 40 or 50 lbs, gives you a little power increase,  and keeps bedroom cooler. Have put them on 4 coaches and notice little change in noise level, different tone, but no louder.
Not for use if you have a jake, put a resonator on a series 60, and first time I used the jake, thought someone was  shooting at me.

While I'm not sure if it's true, I have heard some say a Detroit 6V92 with a straight pipe is louder than a Cummins 8.3 with a straight pipe.

Our 8.2 DD with a straight pipe is still a lot quieter than most of the Harleys I have heard. And the folks driving them don't give a damn about the loudness.
I care, and most of us here are considerate of others and ease out of RV parks even if not utilizing a straight pipe or resonator.

I'm a gonna find that out when I do me some exhaust upgrade! I'm a wanti'n ta put me a resonator on. But a couple other thangs are a gonna happen furst ! :))

While on the parking committee during the recent Alaska Motorcade, I could sure tell who had removed their factory muffler, whether with a straight pipe or resonator, whether at idle or slight power application moving through an RV park.

Bob & sue,    I guess now you are a fan of removing the body panel as I have been pushing for years to do as you too have found out how it gives you unfettered access to any and all problems in each area, and the ease at fixing them with it off.
Well done.
JohnH

John.
 I had already removed the opposite side panel  ( CAC & radiator ) to repair broken mounts on the CAC so I knew the access would be convenient. And there was virtually no way to repair the filon underlayment without taking the panel off. But I did remember your post about it. 
  I would recommend panel removal for anyone wanting to work in the muffler bay area        Then refresh stuff while your in there.

Hey, Guys;
 
Do you need to do anything to protect those areas from the rain while the panels are off?
 
Thanks,
 
Trent

None at all Trent,  that when they are on there is so much road crap and water being thrown around under them that it is no different with off. It is so easy to take them off  and the access to other issues makes it to me a "no brainer".
JohnH

Trent.  The only thing that I did ( with the panel off ) was to wire brush, ospho, prime and re paint the angle iron where the rolocks connect to the side wall.  This can still be done with the panel on  But.    Much more difficult to reach it and treat it.    And the panel now has new stainless screws like the rest of the beltline.

If I had the panel off and rain was expected, I would apply some small pieces of masking tape to the screw holes in the sidewall to prevent water from entering.  And then upon installing the panel I would "bed" the screws with silicone sealer.

My resonator is going in, in a couple of weeks. Looking forward to see what happens with BR temps.
 I got this one:
Amazon.com: MagnaFlow 12774 Exhaust Muffler: Automotive (https://www.amazon.com/gp/product/B000XQO0ZM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1)

Bob,
 
What size screws and what type of heads did you go with?
 
Thanks,
 
Trent