I have an 06 5.9l and was considering removing the muffler for better air flow. I did this on my 04 f-250 (7800 pound turd) and had no increased cab noise. Has anyone done this or heard of it being done on these trucks? Thanks!

 

It is so common that there are muffler delete kits all over the market. Your truck will sound great if you leave the CAT on too. If you want to delete the CAT then there are kits for that also. Actually, if you are going for better flow then you would be better off removing the CAT and leaving the muffler on. Or, better yet, removing the CAT and putting a better flowing muffler on....

 

I'd take door #3, with an Aero Turbine.

 

Thanks for the info.

 

Get ready for lots of Cab noise while towing or when you're on the highway.

 

The exhaust note from our '07 w/the Aero 4040 is barely audible cruising on the highway. I do however think it would be objectionable towing.

 

I run a stock 6.7 muffler on my truck and it even gets some drone, especially when towing. I picked up a nice stainless Bullydog muffler today to add into the mix. I love Craigslist......

 

I took off my stock muffler on an 04.5 and loved it for 2 weeks. I did not notice any more power or mpg increase. Recently I put a $60 muffler (straight through resonator) and love it. The truck is quiet with just the right noise, not too loud. I have a little bit of up and down noise, maybe this is what some call a drone, when I pull a load. I almost feel the truck has more power and better mpg, could this be to a little bit of back pressure which allows the turbo to spool up better? I do not know for sure but I do know that an aftermarket muffler flows good and is way better than no muffler at all.

check ebay

SAS

 

Modifyng the exhaust almost never increases power or mileage on an essentially stock vehicle. The vast majority of the time, it's done just to change the tone or increase the noise level.

Most states and municipalities have specific laws against those changes.

 

What year did they go to a 4" exhaust? After that, I'd agree. But before, maybe not.

 

If it were me I would do it like this:

no cat, Donaldson or Nelson 40" muffler, or Aero4040

no cat, Flo Pro Twister race Muffler (Will give you a richer sound and good flo, compact muffler. http://www.flopro.com/DPmufflers.htm

or:

leave the cat, no muffler or Flo-Pro twister.

Some states consider the turbo a muffler, but check your local laws, there may be added stipulations.

 

I have a Flo Pro on my 06 and it is very quiet, too quiet for my taste but after towing without a muffler or cat it was nice not to have to wear earplugs. I ran the truck with the cat and no muffler for 2 years and it was very nice when not towing but after removing the cat it was time for a muffler.

 

I pulled my muffler, left the CAT. Put on a tip that extends past the body and it will not be very noticible. It is a bit louder towing, but nothing horrible.

 

Dodge switched to full 4" exhaust with the 325/600 engine in 04.5. Of course, that's when ALL Cummins powered Rams started coming with CATS. They also put CATS on the 03-04 Cali version SOs.....

 

My 4.0 has all 4" factory pipe