exhaust

>

It is time to replace the mufflers on my Palm Beach and had the following idea.
delete both mufflers, have muffler shop make custome Y-pipe connected to main pipe
going to the back and install a low restriction performance muffler such as the super trap.
I am not concerned about a bit of rumble as long as it isn't excessive. The mufflers are the
low point on my GMC (thats why one of them is on a shelf in my garage!) and this setup
should add a few inches of clearance and drop a few pounds.
My logic could be flawed so I would appreciate any input.

Dan Vanderknaap
"Loud" 76 Palm Beach
 
This is exactly what Jim Bounds did to his 'Dumpster' that he drove to
Myrtle Beach. Sounded different, but good. Jim may haver some
observations from his trip on this setup. (Spotlight of Jim.............

>>
>
> It is time to replace the mufflers on my Palm Beach and had the
following idea.
>delete both mufflers, have muffler shop make custome Y-pipe connected to
main pipe
>going to the back and install a low restriction performance muffler such
as the super trap.
>I am not concerned about a bit of rumble as long as it isn't excessive.
The mufflers are the
>low point on my GMC (thats why one of them is on a shelf in my garage!)
and this setup
>should add a few inches of clearance and drop a few pounds.
>My logic could be flawed so I would appreciate any input.
>
>Dan Vanderknaap
>"Loud" 76 Palm Beach
>
 
Dan,
Funny you should bring this up, Thom is right, this is the exhaust system I
have on the "dumpster". I have a great many ideas but have not wanted to
try stuff out on customers coaches, maybe I should change the name of my
coach to "lab rat"!

I made up a "Y" pipe with no mufflers and tied it directly to the rail
pipe. I did not use 3" pipe, the rail pipe was aluminized so I kept the
pipes OEM.

At the rear, I turned the pipe 90deg. and put on a low restriction muffler
with 2 ouput pipes from a big block V8 late model car, nothing expensive or
fancy. I have 2 pipes peeking out from under the driver side rear.

Now, you want to know how it works? The major noise I hear is the fuel
sucking through the carb.. It really sounds like a pushed from the driver
seat! No muffler noise under the floor, no heat from the muffler, man it
works super!

You may have to think a bit about the sewer dump hose, mine has no holding
tank, but I think you could horn the muffler back there.

The trip to the rally told me the idea does work and that I want to try it
out on other coaches. Give it a try, the first test subject lives!

Come see the "dumpster" in all of its glory any time in Orlando- free
admission!!!

Jim Bounds
- ---------------------

>This is exactly what Jim Bounds did to his 'Dumpster' that he drove to
>Myrtle Beach. Sounded different, but good. Jim may haver some
>observations from his trip on this setup. (Spotlight of Jim.............
>

>>>
>>
>> It is time to replace the mufflers on my Palm Beach and had the
>following idea.
>>delete both mufflers, have muffler shop make custome Y-pipe connected to
>main pipe
>>going to the back and install a low restriction performance muffler such
>as the super trap.
>>I am not concerned about a bit of rumble as long as it isn't excessive.
>The mufflers are the
>>low point on my GMC (thats why one of them is on a shelf in my garage!)
>and this setup
>>should add a few inches of clearance and drop a few pounds.
>>My logic could be flawed so I would appreciate any input.
>>
>>Dan Vanderknaap
>>"Loud" 76 Palm Beach
>>
>
>
Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
> The trip to the rally told me the idea does work and that I want to try it
> out on other coaches. Give it a try, the first test subject lives!
>

Jim,

That's all I needed to here. As soon as the ground where it is stored is dry
enough, it's
comming off the blocks and heading for the muffler shop. I will let you know how
it
turns out.

Dan Vanderknaap
76 Palm Beach
 
> The trip to the rally told me the idea does work and that I want to try it
> out on other coaches. Give it a try, the first test subject lives!
>

Jim,

That's all I needed to here. As soon as the ground where it is stored is dry
enough, it's
comming off the blocks and heading for the muffler shop. I will let you know how
it
turns out.

Dan Vanderknaap
76 Palm Beach
 
Jim, how about bringing it to New Mexico, along wiht some windshields.
Al

> Dan,
> Funny you should bring this up, Thom is right, this is the exhaust system I
> have on the "dumpster". I have a great many ideas but have not wanted to
> try stuff out on customers coaches, maybe I should change the name of my
> coach to "lab rat"!
>
> I made up a "Y" pipe with no mufflers and tied it directly to the rail
> pipe. I did not use 3" pipe, the rail pipe was aluminized so I kept the
> pipes OEM.
>
> At the rear, I turned the pipe 90deg. and put on a low restriction muffler
> with 2 ouput pipes from a big block V8 late model car, nothing expensive or
> fancy. I have 2 pipes peeking out from under the driver side rear.
>
> Now, you want to know how it works? The major noise I hear is the fuel
> sucking through the carb.. It really sounds like a pushed from the driver
> seat! No muffler noise under the floor, no heat from the muffler, man it
> works super!
>
> You may have to think a bit about the sewer dump hose, mine has no holding
> tank, but I think you could horn the muffler back there.
>
> The trip to the rally told me the idea does work and that I want to try it
> out on other coaches. Give it a try, the first test subject lives!
>
> Come see the "dumpster" in all of its glory any time in Orlando- free
> admission!!!
>
> Jim Bounds
> ---------------------

> >This is exactly what Jim Bounds did to his 'Dumpster' that he drove to
> >Myrtle Beach. Sounded different, but good. Jim may haver some
> >observations from his trip on this setup. (Spotlight of Jim.............
> >

> >>>
> >>
> >> It is time to replace the mufflers on my Palm Beach and had the
> >following idea.
> >>delete both mufflers, have muffler shop make custome Y-pipe connected to
> >main pipe
> >>going to the back and install a low restriction performance muffler such
> >as the super trap.
> >>I am not concerned about a bit of rumble as long as it isn't excessive.
> >The mufflers are the
> >>low point on my GMC (thats why one of them is on a shelf in my garage!)
> >and this setup
> >>should add a few inches of clearance and drop a few pounds.
> >>My logic could be flawed so I would appreciate any input.
> >>
> >>Dan Vanderknaap
> >>"Loud" 76 Palm Beach
> >>
> >
> >
> Jim Bounds/Co-op Motor Works Orlando www.gmccoop.com
 
Dan,

If you look in the archives there were some threads along these lines about
a year ago. It might pay to look them over.

My exhaust runs into a Flowmaster 2.5" in by 3" out "Y" located on the
passenger side. The "Y" is on a 3" 45 degree fitting and feeds an
aluminized 3" pipe running aft.

I kept this "Y" as far forward as I could. This leaves two empty spaces
available between cross members and frame rails where the old mufflers and
old "Y" were. I plan to eventually build and install fresh water tanks in
those two cavities.

At the rear my exhaust makes a gentle 90 degree turn and feeds a Flowmaster
muffler with 3" input and two 2.5" outlets. It is mounted behind the waste
tank gate valve and macerator. If you keep the original sewage dump pipe
this exhaust routing will not work. I use a 3" "T" after the waste tank
gate valve. A clean out plug faces aft and the macerator is side mounted.

Although it is large, there was plenty of room for the Flowmaster muffler in
this area. A nice feature with this muffler is a metal heat baffle is
available to reduce heat passing through the floor into the interior.

Exhaust components are above frame bottoms except my outlet pipes pass under
the frame rail behind the rear drivers side wheel.

Most components are aluminized and I fastened with band clamps rather than
welding or "U" clamps.

A local parts house ordered my aluminized components made by Walker. My
Flowmaster muffler, "Y" and aluminized 3" mandrel bent elbows were ordered
by a local speed shop. Many muffler shops seem to stock cheap tubing which
rusts out quickly. I wanted a lasting system, so I tried to use good
components.

By relocating your muffler aft exhaust gas is some what cooler. The muffler
has less work to do as volume of gas is directly proportional to
temperature. This may be one reason many late model cars have aft mufflers.
With cooler gas they can install a smaller lighter muffler.

Straight pipes were almost loud enough for me 50 years ago. Now I like to
feel the power instead of hear it. If rumble is excessive there is room to
add some resonators after the muffler.

Another consideration is with original mufflers our fuel tanks catch a lot
of heat and sometimes the fuel gets pretty hot.

I'll bet if GM were designing the exhaust today, they would change the
original design.

Don Miller
75 Glennbrook
Shenandoah Valley of Virginia

> It is time to replace the mufflers on my Palm Beach and had the
following idea.
> delete both mufflers, have muffler shop make custom Y-pipe connected to
main pipe
> going to the back and install a low restriction performance muffler such
as the super trap.
> I am not concerned about a bit of rumble as long as it isn't excessive.
The mufflers are the
> low point on my GMC (thetas why one of them is on a shelf in my garage!)
and this setup
> should add a few inches of clearance and drop a few pounds.
> My logic could be flawed so I would appreciate any input.
>
> Dan Vanderknaap
> "Loud" 76 Palm Beach
>
 
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