6" SS EXHAUST STACK

[David Brady]

In other words, it was slow with the 6" and its still slow with

the 5". It would be interesting if you could do a benchmark.

Climb a six percent grade before and after, or put it on a dyno.

I'll have to dig out my fluid flow equations to let you know what

the real restrictions are. Coming out of the turbo with a narrow

pipe should increase velocities due to the Bernoulli principle, but

shortly thereafter you really want to dump it to a wide low back-

pressure exhaust. Without benchmarks it's hard to tell what power

loss you've sustained.



David Brady

'02 LXi, NC



ronmarabito2002 wrote:

I went to 5" muffler on my 8V92 last year. Have not noticed any

change in performance. My logic is the fact that 5" is the outlet

from the turbo. Besides that, 5" is the common exhaust on most of the

over the road rigs today. There are exceptions, but I don't see any

advantage to 6" with the turbo outlet restricted to 5"



R.E. (Ron) Marabito, Dallas, TX 92WB40



--- In "WanderlodgeForum%40yahoogroups.com",
David Brady "dmb993@..." wrote:

>

> The LXi, like your WB, uses a 6 inch muffler. Five inch will

> certainly suck some ponies away.

>

> David Brady

> '02 LXi, NC

>

> Kurt Horvath wrote:

> >

> >

> >

> > Yea I've heard that but the one with the liner has fixed the
high

> > pressure leaks according to the Mfg. Let's hope. Prevost has
from

> > what I recall pipes bent in one piece, they are held together
with

> > those nifty band clamps that seat and conform to the pipe
exterior,

> > If the V-Bands and Flanges don't work out I'll go to those
pipe

> > clamps. The Flanges are also available with three different
types of

> > gaskets, o-ring, flat, and, and, and I can't remember, oh yea
the

> > type I bought, male-female flanges, perfect alignment, leak
free,

> > again according to Vibrant Mfg. There is also a Stainless
Steel

> > Muffler available that may work well on your coach, but it's
inlet

> > outlet is 5" not the 6" like on your coach. well I assume
yours is

> > 6"??? Also it is 10" in diameter which would help with crowed
exhaust

> > tunnel.

> >

> > Kurt Horvath

> > 95 Pt 42

> > 10AC

> >

> > --- In "WanderlodgeForum%40yahoogroups.com"


> > <"Wanderlodge"Forum%40yahoogroups.com>,
David Brady

> > wrote:

> > >

> > > Hi Kurt,

> > >

> > > No thanks, I already have a stock muffler. Thanks for
the links,

> > > there's some pretty nifty items there. Be careful with
those fancy

> > > braided stainless steel pieces. They look sharp, but
they've always

> > > leaked on my turbocharged subaru wrx. Kurt, you've been
around

> > > a few over-the-road coaches, Prevost' and what not, what
do they

> > > run on their exhaust systems; i.e., expansion pipes,
flex pipe, etc.

> > >

> > > David Brady

> > > '02 LXi, NC

> > >

> > > Kurt Horvath wrote:

> > > >

> > > > David, Would you like to take that brand new
muffler off my

> > hands???

> > > >

> > > > According to DD straight pipe & ECU will not
have any issues in

> > the

> > > > 95 vintage S 60.

> > > >

> > > > OEM built that pipe for BB ACAP - As Cheep As
Possible -

> > > >

> > > > The original routing of the pipe leaves the turbo,
source of the

> > > > first failure, cracked the 1st 90 degree turn a
short straight run

> > > > 2nd. 90 degree turn, then into a double ball
connector that also

> > > > telescopes in and out. You can check out that piece
of S---, sorry

> > > > engineering wonder here.

> > > >

> > > > http://www.dynaflexproducts.com/downloads/DP_Catalog_03_pg70-


> > <http://www.dynaflexproducts.com/downloads/DP_Catalog_03_pg70->

> > 89.pdf

> > > > <http://www.dynaflexproducts.com/downloads/DP_Catalog_03_pg70-


> > <http://www.dynaflexproducts.com/downloads/DP_Catalog_03_pg70->

> > 89.pdf>

> > > >

> > > > Page 76 Double Ball Joint with Slip Joint Feature
Allowing Lateral

> > > > Movement length 16 to 18 inches mine measures 14
.55 inches at

> > > > present. This marvel allows for 10 degrees of
angularity 360

> > degree

> > > > rotation 2" of offset 2" axial movement,. Hell the
u joints can't

> > > > move around that much. Besides it was hard clamped
to the mount

> > from

> > > > the engine in front of this connection not to
mention rusted to

> > the

> > > > point that it took an pneumatic impact chisel to
get it apart.. So

> > > > what's the point. You need flex in between the
turbo and the first

> > > > mount.

> > > >

> > > > The Flex Connector with liner I choose is here at

> > > >

> > > > http://vibrantperformance.com/catalog/product_info.php?


> > <http://vibrantperformance.com/catalog/product_info.php?>

> > > > <http://vibrantperformance.com/catalog/product_info.php?


> > <http://vibrantperformance.com/catalog/product_info.php?>>

> > > >

> > cPath=1022_1035_1064_1114&products_id=1008&osCsid=999d7ef5fdd15864bae3

> > > > 3db41abf5ef9

> > > >

> > > > The 2 90 degree turns were fabricated in that
manner because it's

> > not

> > > > easy to bend large diameter pipe in a single 180
degree bend, thus

> > > > they weld 2 90's together, which is the industry
standard for

> > > > manufacturing a 180 degree turn in large pipe
exhausts. Well this

> > > > ain't the factory and we're not constrained by what
is easy. I

> > have

> > > > acquired a 14ga 180 degree U-Tube that has the same
external

> > > > dimensions as the original pipe. I'm not an
engineer but I

> > reasonably

> > > > certain that with the remaining 90 degree bend and
a 45 degree

> > bend

> > > > there will be sufficient back pressure.

> > > >

> > > > There will also be a flexible pipe hanger mount
behind the Flex

> > > > connector mounted on the ceiling of the engine
compartment that

> > will

> > > > support the middle section of pipe and will allow
for any movement

> > > > and or torque that may be transferred to the pipe
by the motor.

> > The

> > > > original clamps for the muffler have to go as they
are 6" but the

> > > > rubber isolated mounting bars will remain and
that's all that was

> > > > there to begin with. So where's the rub? Bub!

> > > >

> > > > Not to take anything away from the engineers that
designed the

> > Bird,

> > > > But there are some glaring deficiencies. 7 way
trailer plug, Air

> > > > Purge System, Watts valve, Accelerator and Brake
peddles, Front

> > Left

> > > > Shock Mount, Relay for Jake Brake, W/D Vent for
Slendide 2000,

> > > > Installation of Refrigerator with inadequate
convection, The seat

> > > > belts mounted to floor instead of the seat, That
reminds me I

> > still

> > > > have to fix that one. Nothing like hitting a road
transition just

> > to

> > > > have the air ride seat bounce and the seat belts
automatically

> > adjust

> > > > for the slack then the air ride seat rebounds and
the belts try to

> > > > cut you in half at the waist. That's just the 95 PT
42. I'm not

> > > > bitchin! I'm fixin

> > > >

> > > > Kurt Horvath

> > > > 95 PT 42

> > > > 10AC

> > > >

> > > > --- In "WanderlodgeForum%40yahoogroups.com"


> > <"Wanderlodge"Forum%40yahoogroups.com>

> > > > <"Wanderlodge"Forum%40yahoogroups.com>,
David Brady

> > > > wrote:

> > > > >

> > > > > Kurt,

> > > > >

> > > > > I agree with Greg. I'm gonna keep mine stock.
There's a bunch

> > > > > of vibration and movement back there. I figure
BB's been

> > building

> > > > > buses a whole lot longer than I have.
Initially I'd scratch my

> > > > > head when looking at the frame and support
pieces, but when

> > > > > you consider that something as big as a bus
must twist and flex,

> > > > > this flexibility needs to be designed in. Make
one piece

> > stronger

> > > > > and you've created a stress raiser someplace
else.

> > > > >

> > > > > I have a friend who transplanted a honda
v-tech motor into a

> > > > > lotus elise. Everything worked but the
alternator mount. The

> > mount

> > > > > insists on cracking. There can be some weird
harmonics and

> > > > > resonant frequencies going on that are
difficult to grasp and

> > > > > only trial and error and a 50 year track
record of building

> > buses

> > > > > can solve (unless you can model it and run
high powered

> > > > > computer finite element analysis on it). He's
still fighting

> > that

> > > > > mount...

> > > > >

> > > > > Okay, I'm off my soap box.

> > > > >

> > > > > David Brady

> > > > > '02 LXi, NC

> > > > >

> > > > > Gregory OConnor wrote:

> > > > > >

> > > > > > Kurt, try and figure why there were 4
bends. it may be that

> > it was

> > > > > > engineered to alow for swing room between
the 'hung exhaust'

> > and

> > > > > > the 'torque reaction of the ruber mounted
detroit'. look at

> > the

> > > > roll

> > > > > > of the torque and see that there is a
place for the movement

> > to

> > > > twist

> > > > > > a union. I kinda think this movement was
the problem with the

> > > > > > resulting crack. crack=result
;movement=cause ;facilitate

> > movement

> > > > > > =repair. may be that BB enginered it
correct but someone

> > > > > > overtightened a band to cure an exhaust
leak??????? you also

> > got

> > > > to

> > > > > > keep the stack from cantilivering off of
the maniford with

> > your

> > > > new

> > > > > > design. Scavenging is one variable in
fuel efficiency. even

> > > > straight

> > > > > > pipes some time will result in lower fuel
economy because the

> > > > intake

> > > > > > variable get screwd. backpressure is
mathed into the computer.

> > > > > >

> > > > > >

> > > > > > ----------------------------------------------------------

> > > > ------

> > > > > >

> > > > > > Internal Virus Database is out-of-date.

> > > > > > Checked by AVG.

> > > > > > Version: 7.5.405 / Virus Database:
270.8.0/1715 - Release

> > Date:

> > > > 10/9/2008 12:00 AM

> > > > > >

> > > > >

> > > >

> > > >

> > > > ----------------------------------------------------------

> > ------

> > > >

> > > > Internal Virus Database is out-of-date.

> > > > Checked by AVG.

> > > > Version: 7.5.405 / Virus Database: 270.8.0/1715 -
Release Date:

> > 10/9/2008 12:00 AM

> > > >

> > >

> >

> >

> >

----------------------------------------------------------

> >

> > Internal Virus Database is out-of-date.

> > Checked by AVG.

> > Version: 7.5.405 / Virus Database: 270.8.0/1715 - Release
Date:

10/9/2008 12:00 AM

> >

>

Internal Virus Database is out-of-date.

Checked by AVG. Version: 7.5.405 / Virus Database: 270.8.0/1715 - Release Date: 10/9/2008 12:00 AM