cummins dsl

I have two buddies that just bought '05 cummins and I was talking to some guys who told me that they come with 4in. exhaust turbo back and I was wondering if this is true. I have not had a chance to look under the trucks yet. If this is the case than there is no need to for them to purchase an after market exhaust system. Thanks.

03CTDCO

Pretty sure the 4'" from the turbo back started in 04.5 trucks
The 03's have 3.5" from the turbo to the muffler then 4" from
the muffler to the tip
The 05's should be like the 04.5's (4" all the way)

PourinDiesel

Yeah its true.

Kyle Graham

Its true not mandrel bent but it is 4 inch most guys have been happy with replacing muffler and installing aeroturbine in place of that other thing in front of the muffler and a 5 inch polished tip you cant forget one of those there worth at least 5hp on a dyno

John Rodriguez

I went straight piped originally, and didn't like how it sounded against buildings / other cars, even when not getting on it at all. I ended up putting a 36" (I think) Magnaflow muffler RIGHT after the downpipe ended, and haven't been happier. It's a straight-through muffler, and very quiet. But the stock pipe doesn't exit far enough to not get the bumper black, so put that blingin' exaust tip on

PourinDiesel

Go 5" with 2 resonators and a muffler!

Mark Craig

cummins dsl,

It is a 4 inch, and decently bent, but still not mandrel bent. Getting mandrel helps drop egt's a bit. We even have a muffler replacement performance straight thru muffler that helps those that don't want to replace the system, it fits the stock pipes exactly and bolts right on after you cut the factory muffler out, it's in T-409 stainless which is slightly better material than the stock material. We also have cat test pipes so you can get a decent flowing system without replacing the entire system. The cost savings vs a replacement system isn't a ton but it is worth it if you're trying to save a buck or two. It saves approx 140.00 over a full system. Call us if you have any questions we'll be glad to help.

Mark @ DPPI

Car_nut57

The exhaust is a 4" system all the way front to back, however the muffler is still very restrictive and some performance is to be gained by doing a cat back system. Banks offers a very nice system that replaces the muffler and tail pipe. One very popular option and we think is one of the best is to use an Aeroturbine with or without resonator right on the cat, then use and off-set pipe and straight pipe to the existing tail pipe. This is a very good option for those wanting to do exhaust and sounds really good as well.

Radman

I've got an '05 too and have considered just swapping out the muffler as posted above, but I'm afraid the second I start doing mechanical stuff, my warranty's going by the wayside. Anyone have experience with this?
Radman

Hoss

Warranty schmarranty. Just do it.