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Topic: Muffler to resonator? (Read 1889 times) previous topic - next topic

Re: Muffler to resonator?

Reply #25 –
the slash tip allows the air to exit in a straight line uninterupted while the round pipe allows a hollow pattern of air that rolls over itself thereby not exiting the pipe cleanly. I made the end of mine like a "flatterned sine wave" so the decibels are low but the effect is actually "sucking" the fumes out as well as being blown by pressure. This gives me about a 3.5% more efficient engine and better fuel economy.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Muffler to resonator?

Reply #26 –
Quote from: kb0zke –
What model Magnaflow? The website doesn't like 1993 Foretravel.
I used the MagnaFlow 12771.  It is 4" in, 4" out, and 4" bore straight through the center.  My exhaust pipe from turbo outlet to muffler is 4", and my tailpipe downstream of muffler is 5".  I used a 4" to 5" adapter from muffler to tailpipe.  It's a dirty D.I.Y. job, but not technically difficult.

7" ROUND 12771
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Muffler to resonator?

Reply #27 –
Quote from: jcus –
Have heard before that slash tip is better for flow, but wonder why?
Has to do with the velocity pressure loss based on exit area and poor exit conditions of the straight pipe creating more turbulence and more resistance. Slashed elbow that you see on otr trucks is good also. 6v92 Detroit 2 stroke engines are flowing  2X amount of exhaust of a four stroke (all other factors being equal, which they are not, hence the term boatload). Donaldson has charts showing expected peak flows. Ultimate may well be a bellmouth exit in the low pressure zone on the back of the coach giving a couple of pounds of free boost while reducing vehicle areodynamic rear drag.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Muffler to resonator?

Reply #28 –
Four stroke racing Motorcycles use three steps in the tubing diameters as it leaves the head.  More even power.  More peak power, more torque
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Muffler to resonator?

Reply #29 –
Quote from: Chuck & Jeannie –
MagnaFlow ... is 4" in, 4" out, and 4" bore straight through the center.  My exhaust pipe from turbo outlet to muffler is 4", and my tailpipe downstream of muffler is 5".
Chuck,

Before I ask this question, I admit that I did not do well in my Fluid Dynamics course:

What is the advantage to using a 5" tailpipe when all of the other pipes are only 4"?

Thanks,

Trent
Trent and Jean Eyler
2000  U295  4003  WTFE  ISC  350
Build#5603 MC#17385

Re: Muffler to resonator?

Reply #30 –
Don't know about Chucks case, on on my isc 350, turbo out is 4 inch, then to a 4 to 5 inch adapter, into exhaust can then 5 inch to chrome tip at back.
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Muffler to resonator?

Reply #31 –
                       When brother Dave was living , he and I tried to figure out how to do this on my coach . Physically it is doable but that is where it stops . Just too involved with all the computer sensors with the particulate filter mess . It is EPA from here to China and back , expensive and complex . Wow , makes me wonder about some of this stuff . This can be done . There is a business in Pittsburg Pa. that can do this . They specialize in the computer programing and that is exactly what is needed . They can take this engine to 850 HP as well , but the tranny can't take that much , so I'll just leave it alone for now . ::)  ::)  ::)  Brad Metzger
Brad Metzger
2010 Phenix 45'

Re: Muffler to resonator?

Reply #32 –
Quote from: TulsaTrent –
What is the advantage to using a 5" tailpipe when all of the other pipes are only 4"?
1.  Big tailpipes are more bad@ss than small tailpipes...this is a known fact...just look at all the "real" trucks you see rollin' coal on the superslab.
2.  Big tailpipes always make you go faster, regardless of what kind of engine you have.
3.  The only thing better than one big tailpipe is DUAL big tailpipes!

Oh, and there is one other reason why I have a 5" tailpipe: Our coach came to us that way, and I re-used the existing tailpipe.  8)

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Muffler to resonator?

Reply #33 –
Brad- I have read many good things about Pittsburg Power, but it comes down to how many coach bucks you want to spend to get more power vs how many miles can you go by spending the same coach bucks on diesel and going out to play with your toys and friends. 
I do have a resonator but not all the power and stuff you have on your newer coach, so as Dave always said, " do what makes you happy."  I love that saying and try to use it every day- thank you Dave.
Ted & Karen
2001 U270 36' - sold after 12 years full timing

Re: Muffler to resonator?

Reply #34 –
I disagree that the transmission cannot take the extra horsepower. Unless you are trying to do Hole Shots leaving the starting line under WOT I do not feel you will ever achieve the torque levels needed to destroy your transmission. Once the Unit is in motion I would find it hard for you to ever reach a point where you were at or over the MAX torque rating for your trans.The thing about High Horsepower diesels is they do not have to work as hard to achieve the same results. With a good ECM program You can see a MPG increase as well as making the unit more pleasurable to drive. My 12.7 Series 60 Detroit is putting just shy of 600 hp to the ground seen on a dyno.It was 430Hp which might have been 350 to the ground before I made changes. I have to watch water temp and know when to back out of it,but the truck is a pleasure to drive and I am less stressed at the end of my day than I would have been fighting a underpowered rig all day long. The programs that Pittsburg Power and other places custom tailor to your application actually allow the engine to breath and operate more efficiently. Your Right Foot is attached to your wallet also and common sense will keep you from destroying the entire package. This is not something you would do if you had multiple drivers in your Rig. Same goes for a guy with a big truck like myself. I am the one that drives it every week, I pay the bills,etc. A employee would not care about taking care of the rig so the standard factory safeties are there to protect your engine. Common Sense has to be Used!! JMO 8)
91 GV U300 Unihome 40' Build 3811
6V92TA Detroit

Re: Muffler to resonator?

Reply #35 –
Chuck, put in a fake 5" pipe coming out the other rear corner.  Cool!
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Muffler to resonator?

Reply #36 –
Quote from: Roger & Susan in Home2 –
Chuck, put in a fake 5" pipe coming out the other rear corner.  Cool!
For serious hp gains add  red stickers, along with the fake outlet. Other colors may well result in a hp loss.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: Muffler to resonator?

Reply #37 –
In reply #21 kb0zke asked: What model Magnaflow?

In 2011 I installed a MagnaFlow 14774 $200  polished SS muffler, 5 in, 5 out, 30 long, 7 OD body. The Magnaflow 12774 is the same muffler which is cheaper because it is not polished. I found the 14774 (polished) on sale for less then the unpolished one.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Muffler to resonator?

Reply #38 –
             About the HP and the tranny . Allison states that 650 HP is max for my model . I agree with you on it staying together , just sort of gave up on the unnecessary  need of it . I'll just suffer along with what I got .But ---I sure do have it on my brain . Brad Metzger
Brad Metzger
2010 Phenix 45'

Re: Muffler to resonator?

Reply #39 –
Long ago the Allison guys allowed Foretravel to use a 277hp/840 torque 6v92 in the original unihomes in 1988.

Trans was rated for 780 torque. 

Allison allowed this because of the light weight of the coaches.

I had so many customers complain about the 277 hp rating that there buddies teased them that THERE motorhome had 300hp(cat) that at the unihome seminar on Oct 87 in Nac I met the Detroit and Allison guys and asked if they could change the rating to 300hp.

They looked at each other and looked at their pocket specs and said that was fine as it lowered the torque to 820.

Side by side racing the 277 pulled the 300 noticeably. Two coach lengths to 60?

"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Muffler to resonator?

Reply #40 –
Fitted the resonator and wrapped with heat tape the help the dash ac , happy with results . Feels less choked, spins up more freely. Just seat of pants assessment.
Jimmy
2003 U295 3620