The original equipment exhaust finally crapped out on the 03 Dodge with cummins. After a bit of research I bought a "cat back" system from Gale Banks. the original equipment pipe was 3.5", the new is 4" d. I took it to a local shop to have it installed and when it was all said and done they had cut away about six inches of the exhaust and welded in a 3" d. section to attach the 3.5" to the 4" system. The joint is right under the feet of the front seat passanger. It turns out they only had 3" in stock so they stretched it on one end to slip in side thenew 4" and slipped it inside the 3.5" to weld it.

Drat! Why is it that exhaust system people have so little idea of how a system flows?

So now I have a 3" long 3" diameter restriction in my brand new high flow banks exhaust.

Anybody have an idea what the will do to my flow?

(The new system sounds wonderful).

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Tell them to fix it correctly. If they whine about it, say that payment on the credit card/check will be stopped ASAP. I have no sympathy for people who do crappy work.

No excuse for that. The work was done by idiots.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

They offered to change it on the spot but I did not want to wait, being hungry and having already spent two hours at it.

the welds were beautiful.

I plan to get a piece of pipe for them to use from Gale Banks. they should have supplied something to hook to the existing pipe or tried at least to sell me a new front down pipe.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Don't know what it will do to your flow, but can tell you my Duramax pulls harder and has lower EGTs with my 5" turbo back exhaust!

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-Justin

91 560 SEC AMG - other dogs dd
01 Honda S2000 - dogs dd
07 MB ML320 CDI - dd
16 Lexus IS250 - wifes dd

it's automatic.

The cross sectional flow area at three inches is so reduced I would expect leaving it in may almost act as a choke reducing the new advantages or a portion of them . The three and a half to four inch adapter is a requirement. A three inch pipe only has about half the actual flow capacity at a given pressure of a four inch pipe.

Area of a circle is pie x radius squared so 3 inch is 28.26 square inches of flow area where the four inch is 49.24 squared inches of flow area. Almost double as I mentioned.

Did they offer to replace it before or after you saw it?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Hey Tom....

Drive down here and I will hook you up with an exhaust shop that can do a 4 inch straight pipe for you. Probably cost you more to drive down than the exhaust. Bring a trailer and buy my ponton while you are here.

The shop guy is a big Cummins fan and he runs 4 inch straight pipe to behind the wheels and turns it out to the passenger side.

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daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

After.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Well you Did do a cat back system so depending on the down pipe size you still may have a restriction exhausts up stream

Yeah, I'll prolly end up replacing the down pipe with a 4" too.

With the 4" and what looks like a glass pack it is much quieter than my old system which had an actual glass pack. I imagine my old glass pack had lost all its glass packing.

Lovely bass sound now.....deep and cottony.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Why did you need a "cat-back" system, your truck shouldn't have a cat, unless it started life as a NY or California 235 HP truck, and that was for the '04 model year. The engine pipe on that year is 3.5" to the muffler, and 4" from thereon. If you wan't to use a 4" engine pipe, you'll need the exhaust adapter from an '04.5-'07 truck with the "600" engine and catalytic converter.

The biggest restriction in your exhaust is the turbocharger, its outlet is about the size of a golf ball. This is what you want- note the size difference of the turbine outlet, and it's also a dual volute.

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'83 300D, 126K miles.

I saw an 04 Dodge/Cummins truck for sale today that had over 415k miles on it. Guy is asking $3200.

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Jim

What caused the OE exhaust to fail? I'd like to do something lighter and louder on my 300D, but I can't seem to bring myself to cut up a perfectly good original exhaust system.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Well, they don't last forever. If you want a bit of growl, remove the rear muff and replace with a custom bent straight tail. I have done this many times on benzes. If the muff is good I remove it and reinstall when I sell the car.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.