6" SS EXHAUST STACK

[Kurt Horvath]

David,

The Max exhaust outflow from a DD S-60 470 HP motor is 2877 CFM @
875degrees F. these numbers are the same for the 500 HP version..

Then from your calculations of 5" diameter:= 6500 cfm & 6"
diameter:= 10000 5" diameter: 6500 cfm 6" diameter: 10000 cfm you can
extrapolate, the 5" pipe has more than 2.25929 times more capacity
to exhaust the gases the Series 60 is capable of producing and the 6"
has nearly 3.47584 times more capacity than the engine can produce.
If calculate in . back pressure of 2 inches of Hg:5" diameter: 5500
cfm 6" diameter: 8750 cfm. You are still under max. capacity The
flow may be further enhanced by the use of Ceramic Coatings or
Thermal Blankets. To retain flow velocity. I intend to employ both.

Mufflers should be based on flow capacity rather than size because
engines are flow sensitive, not size sensitive. This being so, why
should the same not apply to the selection of mufflers? The answer
is that it should, as the engine's output is influenced minimally by
size but dramatically by flow capability. Buying a muffler based on
pipe diameter has no performance merit. The only reason you need to
know the muffler pipe size is for fitment purposes. The engine cares
little what size the muffler pipe diameters are but it certainly does
care what the muffler flows and muffler flow is largely dictated by
the design of the innards.

I have review all the available mufflers from all mentioned sources,
Fleetgaurd, Nelson, Donaldson and several custom Mfg.'s. I decided to
go with a mfg. Outside the box, who manufacture mufflers for race &
show cars. His design is basically a straight pipe. So to continue
discussing mufflers isn't where I'm going, I don't intend to use a
muffler. I am going to use a pipe that doesn't restrict flow but will
reduce SOME of the noise. Nothing more.

Honestly I would not use anything from any of the typical sources,
due to the one size fits all mentality and the materials used in
their Mfg. . That is not Stainless and the mediocre quality accepted
as OEM quality.

Whether you go 5" or 6" in a Straight Stack it will more than handle
the load.

Kurt Horvath
95 PT 42
10AC


--- In WanderlodgeForum@yahoogroups.com, David Brady
wrote:
>
> And at a back pressure of 2 inches of Hg:
>
> 5" diameter: 5500 cfm
> 6" diameter: 8750 cfm
>
> I think the work you are doing is applicable to my BB. It's
> not quite apples and oranges. Do you have a source for a
> 5" stainless steel straight thru pipe? If you do, I'd like to have
> it. Looking forward to you letting us know how loud a straight
> thru pipe is!
>
> David
> '02 LXi, NC
>
> David Brady wrote:
> >
> > It's a little late, I'll have to check my math in the morning,
> > but for a gas temp of 800 deg F, and a muffler input absolute
> > pressure of 38psi (when I'm less tired I'll revisit this number,
but
> > I think it's ballpark), and assuming a back pressure of 3 inches
> > of Hg, and a tube length of 60 inches, I get:
> >
> > 5" diameter: 6500 cfm
> > 6" diameter: 10000 cfm
> >
> > David
> > '02 LXi, NC
> >
> > Kurt Horvath wrote:
> >
> >> DAVID,
> >>
> >> WHAT IS THE FLOW RATE FOR 5" and 6" staight pipes, I have a new
> >> 86610M I would like to sell it. Evidently were comparing apples
and
> >> oranges, If your coach uses a diffrent muffler. All my research
has
> >> been for the 95-96 PT 42's and it's systems. I can't help much in
> >> regardes to the other model coaches
> >>
> >> Kurt
> >> 95 PT 42
> >> 10AC
> >>
> >> --- In WanderlodgeForum@yahoogroups.com
> >> , David Brady

> >> wrote:
> >> >
> >> > For comparison sake, the manufacturer of the OEM muffler
> >> > is Nelson:
> >> >
> >> > http://www.nelsonexhaust.com.au/pdfs/fleetguard.pdf
> >> <http://www.nelsonexhaust.com.au/pdfs/fleetguard.pdf>
> >> >
> >> > They don't list the LXi muffler in the above pdf, I'll call on
> >> > Monday to see if I can get some CFM specs from them. The
> >> > closest item in the above pdf is a 6" inlet and outlet straight
> >> > thru muffler measuring 282mm dia and 1130mm length, part
> >> > number 86610M. The OEM LXi muffler measures 300mm
> >> > dia, and 1200mm length.
> >> >
> >> > The above pdf lists CFM specs for part number 86610M as
> >> > follows:
> >> >
> >> > at 3 mm of Hg pressure: cfm = 3700
> >> > at 2 mm of Hg pressure: cfm = 3020
> >> >
> >> > I expect the numbers to be even higher for the stock LXi OEM
> >> > muffler. I'll call to get actual numbers, but these are the
kinds of
> >> > CFM's that we should be looking for. So far I haven't seen any
> >> > 5" mufflers coming close to that kind of flow rate at these
> >> pressures.
> >> >
> >> > David Brady
> >> > '02 LXi, NC
> >> >
> >> > David Brady wrote:
> >> > >
> >> > > Kurt
> >> > >
> >> > > I'm more convinced now that 5" is the standard trucking
muffler
> >> > > size cause they run dual stacks. Donaldson doesn't make a
> >> > > muffler that's suitable for the 14L Series 60, in this case
you
> >> have
> >> > > to use dual 5 inchers if you buy from Donaldson. Again, it
would
> >> > > be interesting to take a look at your typical late model 14L
> >> Series
> >> > > 60 equipped Prevost. I know their mufflers exit below the
bumper,
> >> > > but it would be interesting nonetheless. I'm interested in
all
> >> this cause
> >> > > I'll be needing a muffler change in the near future, so let's
> >> work
> >> > > together
> >> > > to arrive at a good solution. I want more horsepower. Let's
figure
> >> > > out how to improve the breathing. Assuming that the intake
is not
> >> the
> >> > > limiting factor, and I don't think it is, enhancing the
exhaust
> >> should
> >> > > improve performance and engine life, less heat, higher
manifold
> >> > > pressures, better fuel mileage and longer piston and ring
life.
> >> Not
> >> > > trying to get under your skin, just looking for a suitable
> >> improvement in
> >> > > my engine. Your the lucky guy who's gotta travel down this
road
> >> > > first.
> >> > >
> >> > > David
> >> > > '02 LXi, NC
> >> > >
> >> > > Kurt Horvath wrote:
> >> > >
> >> > >>
> >> > >> > But Kurt, it's only 5 inches, correct? The turbo dumps
into
> >> > >> > 5 inches but the gases are hot, low density, low pressure
and
> >> > >> > moving fast. As the exhaust progresses down the exhaust
> >> > >> > system the air cools, becomes more dense, and back
pressure
> >> > >> Ø increases.
> >> > >> Ø
> >> > >> Ø CORRECT, THAT IS WHY YOU USE EXHAUST BLANKETS ON THE,
MANIFOLD,
> >> > >> TURBO, PIPES, AND STACK TO KEEP THE HEAT INSIDE THE PIPES
FROM
> >> > >> COOLING THUS MAINTAINIG THE VELOCITY OF THE ESCAPING EXHAUST
> >> > >> Ø
> >> > >> Ø If way down the exhaust you go from 6 to 5 your
> >> > >> Ø increasing the backpressure.
> >> > >> Ø
> >> > >> Ø THE EXHAUST DOES NOT REDUCE DOWN TO 5" FROM 6" IT IS 5"
FROM
> >> TURBO
> >> > >> TO THE END OF THE STACK DICHARGE. A 6" STACK CAN BE BUILT
AS I
> >> > >> DECRIBED BEFOR BUT COSTS ARE DOUBLED. 5' SS TUBE $20 A
FOOT, 6"
> >> SS
> >> > >> TUBE $50 A FOOT
> >> > >> Ø
> >> > >> Ø This will make the exhaust run
> >> > >> > hotter at the turbo, high turbo pyrometer, less turbo
velocity,
> >> > >> > and a reduction in performance. 5 inches is 20 square
inches,
> >> > >> > while 6 provides 30, a whopping 50% improvement. I'm gonna
> >> > >> > stick with the 6 or figure out a way to stuff 2 five inch
> >> stacks
> >> > >> Ø in the corner of the bus.
> >> > >> Ø
> >> > >> Ø I'M SURE THIS GUY COULD BUILD 2-5" STACKS AND HOOK THEM
> >> TOGETHER
> >> > >> WITH A COLLECTOR AT THE START LIKE HEADERS
> >> > >> Ø
> >> > >> Ø If you take it down to 5 inches, let
> >> > >> > us know if your turbo pyrometer shows excessive temps on
> >> > >> > those long 6% grades. I think the key is
eliminating/reducing
> >> > >> > back pressure.
> >> > >> >
> >> > >> > Do you have a web page for the 5" stack that you'd like to
> >> > >> Ø use?
> >> > >>
> >> > >> NO THEY DO NOT LIST THE STACK IT IS CUSTOM BUILT
> >> > >> >
> >> > >> Ø Check this out:
http://dieselinjection.net/BRUCE/articles.html
> >> <http://dieselinjection.net/BRUCE/articles.html>
> >> > >> <http://dieselinjection.net/BRUCE/articles.html
> >> <http://dieselinjection.net/BRUCE/articles.html>>
> >> > >>
> >> > >> IT WILL TAKE SOME TIME TO ASSIMULATE ALL THAT
> >> > >> >
> >> > >> >
> >> > >> > David
> >> > >> > '02 LXi, NC
> >> > >>
> >> > >> >
> >> > >> > David
> >> > >> > '02 LXi, NC
> >> > >>
> >> > >> --- In WanderlodgeForum@yahoogroups.com
> >>
> >> > >> , David Brady
> >>
> >> > >> wrote:
> >> > >> >
> >> > >> > But Kurt, it's only 5 inches, correct? The turbo dumps
into
> >> > >> > 5 inches but the gases are hot, low density, low pressure
and
> >> > >> > moving fast. As the exhaust progresses down the exhaust
> >> > >> > system the air cools, becomes more dense, and back
pressure
> >> > >> > increases. If way down the exhaust you go from 6 to 5 your
> >> > >> > increasing the backpressure. This will make the exhaust
run
> >> > >> > hotter at the turbo, high turbo pyrometer, less turbo
velocity,
> >> > >> > and a reduction in performance. 5 inches is 20 square
inches,
> >> > >> > while 6 provides 30, a whopping 50% improvement. I'm gonna
> >> > >> > stick with the 6 or figure out a way to stuff 2 five inch
> >> stacks
> >> > >> > in the corner of the bus. If you take it down to 5
inches, let
> >> > >> > us know if your turbo pyrometer shows excessive temps on
> >> > >> > those long 6% grades. I think the key is
eliminating/reducing
> >> > >> > back pressure.
> >> > >> >
> >> > >> > Do you have a web page for the 5" stack that you'd like to
> >> > >> > use?
> >> > >> >
> >> > >> > Check this out:
http://dieselinjection.net/BRUCE/articles.html
> >> <http://dieselinjection.net/BRUCE/articles.html>
> >> > >> <http://dieselinjection.net/BRUCE/articles.html
> >> <http://dieselinjection.net/BRUCE/articles.html>>
> >> > >> >
> >> > >> >
> >> > >> > David
> >> > >> > '02 LXi, NC
> >> > >> >
> >> > >> > Kurt Horvath wrote:
> >> > >> > >
> >> > >> > > Gregg,
> >> > >> > >
> >> > >> > > Yea, ALL SHOW AND NO GO!-
> >> > >> > >
> >> > >> > > David,
> >> > >> > >
> >> > >> > > I know what you're after but the pipes I described are
> >> basically
> >> > >> > > straight pipes with a very well designed sound
surprising
> >> ceramic
> >> > >> > > coating that does not restrict flow. But won't be as
harsh
> >> as a
> >> > >> > > straight pipe. Cost is nominal at $250.00 Vs $200 for a
> >> straight
> >> > >> pipe
> >> > >> > >
> >> > >> > > Kurt Horvath
> >> > >> > > 95 PT 42
> >> > >> > > 10AC
> >> > >> > >
> >> > >> > > @yahoogroups.com, "Gregory OConnor" wrote:
> >> > >> > > >
> >> > >> > > > Kurt, I dont think big thick straight pipes were
mounted on
> >> > >> those
> >> > >> > > > rigs for performance or efficiency. its all looks and
> >> > >> compensation.
> >> > >> > > > Bet every trucker with 8 inch stacks also drive a 4x4
> >> requiring
> >> > >> a
> >> > >> > > > step latter to get into.
> >> > >> > > > Greg 94pt,toyota pickup
> >> > >> > > >
> >> > >> > > > --- In WanderlodgeForum@yahoogroups.com
> >>
> >> > >>
> >> > >> > > , "Rob
Robinson"
> >> > >> > > > wrote:
> >> > >> > > > >
> >> > >> > > > > Kurt two years ago up here in BC I saw a millenium
> >> Bluebird
> >> > >> > > parked
> >> > >> > > > across
> >> > >> > > > > from me at my home RV park that had two stacks. The
> >> owners
> >> > >> were
> >> > >> > > only
> >> > >> > > > > visiting and must have been out sight seeing most
of the
> >> time
> >> > >> > > > because I
> >> > >> > > > > never did see them. I sure would have like to see
behind
> >> their
> >> > >> > > > engine bay.
> >> > >> > > > >
> >> > >> > > > > 2008/11/1 Kurt Horvath
> >> > >> > > > >
> >> > >> > > > > >
> >> > >> > > > > > I guess you could or go to a large 8" single ,
bit the
> >> > >> chrome
> >> > >> > > > shops
> >> > >> > > > > > sell them for outrageous prices---$692.00
> >> > >> > > > > >
> >> > >>
http://www.iowa80.com/DirectionsWEB/webc...splay.php?
> >> <http://www.iowa80.com/DirectionsWEB/webc...splay.php?>
> >> > >>
<http://www.iowa80.com/DirectionsWEB/webc...splay.php?
> >> <http://www.iowa80.com/DirectionsWEB/webc...splay.php?
>>
> >> > >> > >
> >> <http://www.iowa80.com/DirectionsWEB/webc...splay.php?
> >> <http://www.iowa80.com/DirectionsWEB/webc...splay.php?>
> >> > >>
<http://www.iowa80.com/DirectionsWEB/webc...splay.php?
> >> <http://www.iowa80.com/DirectionsWEB/webc...splay.php?>
> >> >>
> >> > >> > > > > > itemid=74151
> >> > >> > > > > > Kurt Horvath
> >> > >> > > > > > 95 PT 42
> >> > >> > > > > > 10AC
> >> > >> > > > > >
> >> > >> > > > > > In WanderlodgeForum@yahoogroups.com
> >>
> >> > >>
> >> > >> > >
> >> > >> > >> > > > 40yahoogroups.com>,
> >> > >> > > > > > David Brady wrote:
> >> > >> > > > > > >
> >> > >> > > > > > > Now we're talking. Can you fit two stacks back
> >> there? I'm
> >> > >> > > > > > > serious. This will be an improvement in
performance.
> >> Two
> >> > >> > > stacks
> >> > >> > > > > > > will dramatically reduce backpressure, which
will
> >> result
> >> > >> in
> >> > >> > > > > > > lower turbo pyrometer temps, and will allow more
> >> boost and
> >> > >> > > > > > > more power. A single 5 inch, as compared to the
> >> stock 6"
> >> > >> > > > > > > will do the reverse.
> >> > >> > > > > > >
> >> > >> > > > > > > David
> >> > >> > > > > > > '02 LXi, NC
> >> > >> > > > > > >
> >> > >> > > > > > >
> >> > >> > > > > > > Kurt Horvath wrote:
> >> > >> > > > > > > >
> >> > >> > > > > > > > One pipe from the turbo then splits to two
stacks.
> >> > >> > > > > > > >
> >> > >> > > > > > > > Kurt Horvath
> >> > >> > > > > > > > 95 PT 42
> >> > >> > > > > > > > 10AC
> >> > >> > > > > > > >
> >> > >> > > > > > > > --- In WanderlodgeForum@yahoogroups.com
> >>
> >> > >>
> >> > >> > > 40yahoogroups.com> > >> > >> > > > 40yahoogroups.com>
> >> > >> > > > > > > > > >> > >> 40yahoogroups.com > >> > >> > > > 2540yahoogroups.com>>,
> >> > >> > > > > > David Brady
> >> > >> > > > > > > > wrote:
> >> > >> > > > > > > > >
> >> > >> > > > > > > > > But doesn't the trucking industry run dual
> >> exhausts?
> >> > >> > > > > > > > >
> >> > >> > > > > > > > > David Brady
> >> > >> > > > > > > > > '02 LXi, NC
> >> > >> > > > > > > > >
> >> > >> > > > > > > > > Pete Masterson wrote:
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > Having recently replaced my muffler (at
great
> >> > >> expense) -
> >> > >> > > -
> >> > >> > > > had
> >> > >> > > > > > I
> >> > >> > > > > > > > to do
> >> > >> > > > > > > > > > it over again, I'd have switched over to
a 5"
> >> system
> >> > >> > > from
> >> > >> > > > > > turbo to
> >> > >> > > > > > > > > > stack. As others have stated, it's 5" at
the
> >> turbo
> >> > >> > > outlet
> >> > >> > > > and
> >> > >> > > > > > the
> >> > >> > > > > > > > > > standard in the heavy truck industry is
5".
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > The only performance difference I notice
> >> (between
> >> > >> the
> >> > >> > > old
> >> > >> > > > > > blown
> >> > >> > > > > > > > out
> >> > >> > > > > > > > > > muffler and the new one) is that the
exhaust-
> >> type
> >> > >> Jake
> >> > >> > > > brake
> >> > >> > > > > > > > seems to
> >> > >> > > > > > > > > > be slightly less effective.
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > Pete Masterson
> >> > >> > > > > > > > > > '95 Blue Bird Wanderlodge WBDA 42
> >> > >> > > > > > > > > > aeonix1@ > >> > >> > > 2540mac.com>>
> >> > >> > > > > > > > > > On the road at Hohenwald, TN (Natchez
Trace
> >> Parkway)
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > On Oct 31, 2008, at 11:24 PM, Kurt Horvath
> >> wrote:
> >> > >> > > > > > > > > > > <snip>
> >> > >> > > > > > > > > > > For the last four weeks I have queried
> >> Detroit
> >> > >> Diesel,
> >> > >> > > > > > Custom
> >> > >> > > > > > > > Exhaust
> >> > >> > > > > > > > > > > Fabricators, Several OEM Exhaust Mfg.'s,
> >> Marine
> >> > >> > > Exhaust
> >> > >> > > > > > > > Engineers &
> >> > >> > > > > > > > > > > Fabricators, My BB Guru, and anyone
else that
> >> > >> would
> >> > >> > > > lend an
> >> > >> > > > > > > > ear, and
> >> > >> > > > > > > > > > > no one has expressed any apprehension or
> >> regard
> >> > >> in the
> >> > >> > > > > > respect
> >> > >> > > > > > > > to a
> >> > >> > > > > > > > > > > 5" exhaust system. In fact all parties
> >> expressed
> >> > >> their
> >> > >> > > > > > surprise
> >> > >> > > > > > > > in
> >> > >> > > > > > > > > > > respect as to why the system would
change
> >> size at
> >> > >> the
> >> > >> > > > > > muffler.
> >> > >> > > > > > > > > > >
> >> > >> > > > > > > > > > > Several owners have modified their
systems
> >> to 5"
> >> > >> from
> >> > >> > > > end to
> >> > >> > > > > > > > end, and
> >> > >> > > > > > > > > > > have seen no change in performance.
Positive
> >> or
> >> > >> > > > negative, In
> >> > >> > > > > > > > general
> >> > >> > > > > > > > > > > it was just a matter of convenience in
> >> acquiring
> >> > >> > > parts,
> >> > >> > > > I
> >> > >> > > > > > won't
> >> > >> > > > > > > > get
> >> > >> > > > > > > > > > > into that. That has recently been
beaten to
> >> death
> >> > >> at
> >> > >> > > the
> >> > >> > > > > > > > expense of
> >> > >> > > > > > > > > > > all parties involved
> >> > >> > > > > > > > > > >
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > ------------------------------------------
-----
> >> -----
> >> > >> ----
> >> > >> > > --
> >> > >> > > > > > > > ------
> >> > >> > > > > > > > > >
> >> > >> > > > > > > > > > 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
> >> > >> > > > > > > >
> >> > >> > > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > > >
> >> > >> > > > >
> >> > >> > > > >
> >> > >> > > > >
> >> > >> > > > > --
> >> > >> > > > > Rob, Sue & Merlin Robinson
> >> > >> > > > > 94 WLWB
> >> > >> > > > >
> >> > >> > > >
> >> > >> > >
> >> > >> > >
> >> > >> > > --------------------------------------------------------
--
> >> > >> ------
> >> > >> > >
> >> > >> > > 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
> >>
> >
> >
> > ------------------------------------------------------------------
------
> >
> > 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
> >
>