$ for going to 4" exhaust in 2003

[CraigJones]

Do I have to get anything else other then a down pipe and a new muffler to go 4" exhaust all the way out ? I'm think Donaldson 51" but I need suggestions on were to get the down pipe. I want my truck to be as quiet as possible. Thanks

 

[SRadke]

You can buy a 4" elbow and downpipe for an 04. 5-05 from Mopar or you could buy just the elbow and outsource the downpipe. When I did my turbo work I bought a downpipe from Rip at Source Automotive He may have a source for Donadson mufflers as well, not sure about that. You may also be able to find a deal on the 04. 5-05 elbow at a shop that installs exhaust brakes.



-Scott

 

[Mark Craig]

CraigJones,



The intermediate pipe is going to need to be replaced too as it's 3. 5 inches.



Mark @ DPPI

 

[JLitton]

I bought a Nelson 51" muffler (#86131M--$80. 67) at Fleetpride and a 4" system minus the muffler and minus the Delete pipe from Rip @ Source Automotive for around $250. You could still use the factory tailpipe as it is already 4". I have it installed and it sounds just like I wanted. Not loud at all. Just a little deeper, but from the cab with the windows up or down I can't hear the exhaust over the turbo whine. ( AFE/ Torque Tube w/no silencer ring) I pull a fifth wheel and did not want the loudness while pulling. I think you will be pleased with the sound. Also, TDR #48 has an article in which they use this exact muffler, so you won't be disappointed. BTW, Rip told me I would be better to buy a 51" muffler locally as opposed to having it shipped in as the shipping cost would be much more than any savings on the price of the muffler. FWIW.

 

[Mark Craig]

JLitton,



Just and FYI for 81. 00 more you can get a complete 4 inch bolt on aluminized system from us, maybe you wanted the super size Donaldson for a specific reason but thought I would let you know what we had available.



Mark @ DPPI

 

[100 Proof]

Unless you are doing, or planning, a turbo upgrade, available data indicates you will see little or no benefit from a full 4" system. The tiny turbo is by far a larger restriction than the 3. 5" exhaust piping. Just have a muffler shop put on the Nelson 86131M to enjoy the EGT reduction and gain a nice growl. You'll be into the whole project only about $150 (less if you install it yourself). I got my 86131M at my local Cummins dealer.



See Doug's article where he talks about this upgrade in the current TDR issue.



100 Proof

 

[midlife crisis]

What is the egt reduction & performance gains (mpg?)of the aluminized dual system, without changing the stock downpipe to 4"? Stock SO, no turbo changes planned--

 

[SRadke]

I saw about 50° temp reduction and no appreciable mileage from a full 4" system. There isn't a lot (besides noise) to be gained on a stock truck.



-Scott

 

[100 Proof]

What is the egt reduction & performance gains (mpg?)of the aluminized dual system, without changing the stock downpipe to 4"? Stock SO, no turbo changes planned--

Without boost fooling you typically LOSE a few horsepower with an exhaust mod! :{

My EGT reduction is in the 25+ degree range.



100 Proof