Couldn't stay away any longer. Missed those days under the coach.

My exhaust system is far from the original stock dual system. I have Thorley headers which join into a single muffler on the driver side. The single exit pipe then runs straight back a bit, then angles out in front of the rear tires. Not bad for low restriction but a bit more "big bore roar" than I need.

I am in the process of quieting down the Barth, so I decided to install another muffler in the straight section behind the first muffler.

The original straight section:



I cut out 24 inches and installed the largest muffler that will fit. I remounted the hanger between the 2 mufflers.



(I had to bend the driveshaft out of the way but that shouldn't be any trouble)



The noise reduction was immediately obvious. Haven't done any road trips but it should be much quieter. Now to work on the doghouse!

I think your going the wrong way. Back in 1980 I bought a new H.D. had all kinds of mechanical noises. 2 days later, a set of strait pipes and all those noises disapeared.

But see the problem is... I'm half deaf in the left ear (cheap 12 gauge shells in high school, no ear plugs...) So all I got is my good right side to hear my wife complaining (oops, I meant"talking") and if the coach is too loud I miss the important things she has to say...

I could just go the modern isolationist route: ear plugs and loud chainsaw metal music...

Doorman is right Steve, install straight pipes and you'll no longer hear Liz complaining I mean talking!

Looks great should be much quiter now, mine has the dual exhaust, it's really quiet. I thought about adding some rumble make that 454 roar a bit on the other hand it's a coach not a dragster.

And they say chocolate is addictive!

I got some marine use sound deadener in a swap for work and lined the inside and out of the doghouse. Found out later it's very expensive stuff, but it really killed the sound.

Here's a thread from 09 with pics from Bill and me.
http://barthmobile.com/eve/for...?r=48210406#48210406
Just realized I never answered the question about Barth tape. It's a grey heavy duty cloth tape available at any hardware store. [They call it duck tape, for some odd reason].

Sound Deadening and Heat Transfer:


When I recarpeted my Barth, I used an item called FatMat. I used probably $400 worth of it. I went crazy with it. It is a lot cheaper than Dynamat (I think it is $125 for 100 square feet). It is a self-adhesive rubberized material with foil on one side. I put 2 layers above the engine, all the way back to the doorway, 3 layers on the top and 3 more layers on the underside of the doghouse. I then put 1 layer of bubblewrap with foil on both sides on top of everything ( stapled it but did not put on underside of doghouse) and then put the carpet pad and carpet. I also caulked and sprayed foamed all cracks and joints I could find. I found that Barth was not too careful about sealing around the dog house. I found HOLES that I could stick fingers through and the only thing to stop the noise was the carpet and pad. Also, there is a metal "firewall" under the dash that I was getting a lot of noise and heat through. It was impossible to get large pieces of FatMat through the front engine access or up underneath. SO HERE'S WHAT I DID: I cut small pieces of all sizes, 4'x'6, 5"x5" etc....any size I could and would reach up from the front access adn from under the dash and stick them any and everywhere on the metal firewall. It took awhile and doesn't look great from underneath but it really did the trick.

My wife and I can converse in regular voices going down the road. I can BARELY hear the clutch van kick in. I can't hear the engine idling either.

One other item that might work and might cost less than FatMat would be the rubberized water shielding you all use back East near the edges of your roofs to prevent ice-dams. It appears to be very similiar to FatMat but without the foil. We don't use it here in the lower Midwest adn cannot get it.

Hope that helps someone

K&E

This is just the reason I love this site! Thanks for the tips on sound insulation materials and techniques. Saves me from having to search around as much. I need to ask my dad what he used on his boat, it worked very well.

I have 4 stages in mind for noise reduction:

Reduce noise at source (mufflers, air silencer, etc)
Seal gaps around doghouse, floor, firewall, window seals too
Apply sound absorbing insulation to doghouse
Additional insulation on floors and firewall

I intended to do these before Milford but I got a little sidetracked with that crankshaft thing...

oops, thread drift... I'll put my 2 cents when I get that stuff done and start a thread with some more pics. Thanks for the feedback.

WINDOW RATTLING NOISE


One thing I forgot....I had an issue on my coach with the windows rattling. The felt was dried out and probably needs to be replaced...so I would open the window and put a piece of black electrical tape on the edge of the window and close it firmly. This was just enough to almost completely stop the rattling...

Hope it helps someone!

K&E

Noisy Kohler Genny


Couple of other things... To help quiet my Kohler, I cut a piece 3/4 rubber matting between the generator and the generator slide drawer.

For $30, I got a 4ft x 6ft piece of 3/4 inch HEAVY rubber matting from Tractor Supply that is used in horse stalls. Also, I used some of the header wrapping material from NAPA and wrapped the exhaust pipes on the generator. Both really helped and cut the vibrations....

quote:

Originally posted by Steve VW:


My exhaust system is far from the original stock dual system. I have Thorley headers which join into a single muffler on the driver side. The single exit pipe then runs straight back a bit, then angles out in front of the rear tires. Not bad for low restriction but a bit more "big bore roar" than I need.

I am in the process of quieting down the Barth, so I decided to install another muffler in the straight section behind the first muffler.



The noise reduction was immediately obvious.

I took a slightly different path.

Our Barth already had factory duals, so when I put in the Thorleys, I just connected them straight to the factory mufflers.

The hotrodder in me said the 502 needed more flow, so the stockers were replaced by a pair of Afterburners. Essentially turbo mufflers.

It was pretty decent until I put in side dumps. Sounded too much like a hot rod, especially on the backrap with the driver window open, since I was hearing only four cylinders, with the impulses spaced unevenly apart. So, in went an H pipe.

That helped the noise and midrange throttle response, but still a little too loud, especially since I drive with the window open a lot.

Next was an X pipe. Works fine. More power, less noise. Still has a rasty idle. Every now and then, someone's head will turn and he will walk over and say, "Whaddya got in that thing?"

But smooths out nicely when under way. Sounds quite nice. Just a BIG engine, but not a noisemaker hot rod. Seems like more power across the whole power band, as well.

I have to say, I'm thankful for the simplicity of a DP's exhaust; I've replaced it all. 3" flex from the turbo, to a 3" input, 4" output muffler, 4" elbow, and 4" stainless tip.

Bill h that system is sweet! If I were going to go with duals I'd do the same thing. For now the second muffler seems OK, better than before. Not too sure about power since I don't climb much.

The muffler I used is a Series 70 Flowmaster Big Bore. Not straight through but fairly open I think. The different length collector pipes are not in phase, idle has some rumble but down the road is pretty smooth.

Now that I'm lounging in the Keys I wanted to be sure people know it is not all warmth and relaxation, (except for Liz and the cat of course.) Besides, things are bit slow here on the site.

The original system was dual exhaust all the way back. Before I got it, headers and a 2 to 1 system were installed. It was a bit loud so I installed a second muffler as detailed above.

Having replaced the old 454 with the HO version, I decided dual exhaust would be better for the new engine. I decided to reinstall the second exhaust system.

First I bolted in a perforated steel angle. I had to eyeball the side to side clearance, settled on a location and bolted to the 3 cross members on the frame. The perforations allow me to mount the hangers anywhere I need them.



I needed a 3rd hanger in front of the two mufflers but the tag axle brake system was in the way of the angle. I bolted the 3rd hanger to the tag axle bracket. Played around a bit with the front to back locations and bolted in the hangers.





Next the two mufflers. I went with the same layout as the other side to balance the sides for flow.







Straight muffler in front (school bus type) and Flowmaster 70 in rear. I have a 3 inch stainless 90 degree bend and stainless pipes for the tailpipe.

I measured for the front head pipe and tail pipes and will finish soon.

Photobucket is slower than ever. What a PITA.

to be continued: