4" exhaust

[REC]

I have some questions about 4" dia. exhaust. On my truck, the exhaust flange of the turbo is 3" and this continues to a resonator? and then its 4" to the muffler and then 3" the rest of the way. Some after market systems I have seen claim 4" from the turbo. My local muffler guy wants to do 4" from the muffler back. What exactly are the gains to be had and which version will yield the best results? This truck is used almost exclusively for pulling a travel trailer.

 

[CumminsAholic]

You'll gain both ways, but I'd go with a 4" all the way back. No sense in necking it down right away and then trying to free it up 5 feet from the turbo. You'll notice a bigger drop in egt's with the full 4" system. Also what's the price difference? There's a lot of 4" systems that are pretty cheap, but be careful, a couple of them come with a 3" downpipe that expands to 4" at the end of it, not 4" right by the turbo.

Corey

 

[BKenny]

My Rips 4" system tapers down right at turbo flange. Brian

 

[Mark Craig]

REC,



Sounds like someone has made some changes to your factory system, they are noramlly the same size front to rear all the way! Get a 4 incher, it'll be necked down a little at the turbo so you can bolt on but from there back it should be 4 inch all the way. Take a look at the MBRP or AFE systems, they are available in aluminized and stainless and fit easily, you could do it yourself if you wanted in the driveway and save some money! The MBRP even has 100% welded hangers that reuse the stock rubber mounts, super easy install!



Mark @ DPPI

 

[wlowe]

My old stock exhaust system was the same way, all 3" with 4" between the resonator and muffler. I replaced it with a 4" turbo back MBRP. My old aluminized system had almost no rust after five years, (no road salt), so I went with aluminized on the new system and painted it with high heat ceramic silver paint, looks great and should last even longer than the old one.

 

[Elite1]

Mark, Have your customers been happier with the 4" system vs. the 5" ?

I would like to get the 5" just in case I do some serious bombing in the future, but don't want it, if there will be too much cab noise.

 

[Bekim]

I have some questions about 4" dia. exhaust. On my truck, the exhaust flange of the turbo is 3" and this continues to a resonator? and then its 4" to the muffler and then 3" the rest of the way. Some after market systems I have seen claim 4" from the turbo. My local muffler guy wants to do 4" from the muffler back. What exactly are the gains to be had and which version will yield the best results? This truck is used almost exclusively for pulling a travel trailer.

The change to 4" will DRAMATICALLY lower back pressure! Lower EGT's and different spool rate. DO IT! DO IT NOW!! It's the single biggest performance change you can get for the cost involved and NO risk=no brainer!!!!!!!!!
Cheers
Mike
###

 

[Turbo Thom]

Mark..... you'll find that's true up to the 03 models. Us older truck are like what he said.

 

[Mark Craig]

Elite1,



yes as an oberall opinion the 4 is waaay more popluar and liked etc. Plus you're good to 500RWHP before a 4 inch starts (Starts to Now) to hold you back at all. The 5 inch is louder and some folks love that, if you're not into loud go with the 4. 0, you'll get all the egt drop and none of the loud that goes with the 5. 0.



Mark @ DPPI

 

[Mark Craig]

Turbo Thom,



Ok, I thought they were 3. 0 all the way to the muffler, not just to the resonator etc.



Mark @ DPPI

 

[JessePayne]

I just put a 4" mbrp aluminized on my truck last weekend. Its has more bass but is very easy to get used to. Check ebay I got the complete exhaust with a stainless tip and free shipping for $346. Easy to install