I'm getting ready to pull the trigger on a diamond eye 4" system for my truck.
Now to decide if I go straight pipe or with muffler. Is there much difference between the two? I love the straight pipe sound on a diesel. I'm wondering if the sound level will be controllable with my foot? I don't want to annoy my neighbors too much, or attract the attention of certain black and white cars.

Any opinions/ experiences are greatly appreciated

 

I vote no muffler. I LOVE the sound of my truck. Actually I love the sound of all straight pipe Cummins. The best part is when you drive up and people say. "I heard you coming a mile away" As far as cops, I don't worry about the noise coming out my tailpipe. Its all the black smoke that I'll probably get pulled over for.

Jake

 

I will be putting a muffler on mine.

 

Around here it's illegal to have no muffler but nobody will usually jab you about it. I love the sound of straight pipe but dont know if I deal with it as a DD. I currently have a Aeroturbine. Its not loud but sounds good!

 

Do no muffler. It's very tolerable. Although I pretty much can't talk on the phone anymore. I will never put a muffler on mine.

You will get mote HP if you USE a muffler!! Seems backwards right? It allows back pressure to regulate a little bit sooner than the end of the tail pipe. Maybe good for a whole .5 HP.

 

I ran without one when I put the 5" stuff on, it was fine in the cab but lord help someone who was stuck near my right rear bumper area. Sounded awesome but I put the muffler on to fly a little lower on the radar screen.

 

the muffler that is included is a straight thru type anyway.

 

I ran for a few years with no muffler and perhaps i'm getting old but I went back to a 4" with muffler. Still has a growl and is bearable.

 

Ok, so I ordered the system today. I got the straight pipe.
Call it a mid life crisis. I turn 43 next week
I can always add a muffler later when my age, or the cops catch up with me.

 

I went straight pipe but I am going back to a muffler, sucks not being able to have a conversation while driving.

 

I straight piped mine shortly after I got it had it that way for about 3 months it was 3 inch but I put a muffler on it to keep those bubble gum machines off my .

 

Depending on your states inspection law, (if you have one) I would suggest installing a 4" muffler on it. They are flow through anyways, so its not a big deal IMO, why not just install it.

I am half deaf from riding in mine so take that into consideration too as well as its hard to even have a conversation inside the cab at cruise speed.

 

My vote is definetly NO muffler. I sure do like the sound of a straight pipe system better. Just my 2 cents.

 

There are no inspections here other than emissions, and my truck is exempt. Most of my drive time is alone, so I'm not terribly concerned about conversation.
I'll probably have to upgrade the sound system next.

 

Mine has stock turbo back to a muffler delete, out the stock exhaust tip, rattling next to my dads ole CAT dual straight piped Peterbuilt, we are actually about the same as far as decibels. Spool em up different story, but i sure love people thinkin im runnin a semi, till they see the truck