KRB

Based on all my searches it looks like the Diamond Eye exhaust is the best bang for the buck.

My question is, should I get the muffler or not? I don't care what it sounds like to those outside, what I need to know is does the diamond eye muffler make the cab quieter and if so, at any change to performance, EGTs, etc?

Many thanks,

BILTIT

I run the DE with muffler, the engine makes more in-cab noise than the exhaust.

Hillbilly66

^^^ what he said. Mine is a club cab, only time I hear the exhaust over the engine is if my right foot gets a little heavy.

As far as EGTs go, I'm not sure what the truck ran before the DE exhaust, because I did not have a pyro. But on my last trip thru New Mexico in October pulling roughly 13k running steady 75mph I never saw over 1250, it would start to rise when I would pull some of the grades tho.

mknittle

I bought the Diamond Eye with the muffler. my thinking is if I get the straight pipe and don't like it the muffler is over $100 for the muffler but the muffler delete pipe is less than half that. I figured I would have a muffler delete pipe made up the same length as the muffler and if I don't like it I can put the muffler on.
there isn't much difference in price for the straight pipe and the one with the muffler from Diamond Eye. If I use band clamps it would be easy to switch one way or the other for cheaper. if that makes sense.

About the sound I don't know yet as I haven't got my truck together yet.

thrashingcows

That is some good thought processes there!

I have a big 4" straight through muffler...I was told it was a OEM muffler from a 07 Cummins truck? Neighbour in my area asked if I wanted it...Free!...Sure I'll take pretty much anything that is free!

I installed it and it has a nice sound, and really cut out all that drone the straight pipe used to generate. But I'm still running the OEM 3" exhaust....But all held together with those magical Band clamps. Love those things!

Angry Johnny

If you buy the DE from Summit the kit with the muffler is only $1 more. I put the muffler on my truck, no need to draw attention to myself, especially from law enforcement.

The DE muffler is a straight through design anyway, it can't possibly hurt it much at all.

mknittle

Ya can't go wrong at $1 for the muffler. the one that came in my kit is stainless

Around here there are so many diesel trucks with straight pipes I wouldn't worry about the cops. I Have seen old men driving trucks with straight pipes. the law aren't lax, the cops are. you should see the county "government center" About 40 drug addicts bums moved onto one of the lawns 4 months ago. They pitch tents, the women run around naked, and they deal drugs. All the cops do is tell them Don't do that and leave.

aicomp

I run the 4" DE with the muffler and I really like it. I had the straight pipe for a while and just wanted it a little quieter.
Mark, my Son lives in Auburn and has his 2007 straight piped. His cop friends love the sound of it.
Mike

mknittle

Thanks Brian, That is a hangover from doing years of the prototype stuff. When you are not absolutely sure make what you are doing reversible.


And the band clamps are the best thing to clamp exhaust ever made!

Redtruck-VA

I must be doing something wrong. I have a pieced together 3" straight system and it is quiet. OEM down tube, a straight pipe section and a tail section from my hemi truck. If the motor isn't turned up are they generally quiet? I'm new to diesel if you can't tell..... lol

Angry Johnny

They aren't real loud straight piped, especially with the smaller 3" system under most circumstances. Well at least if you aren't at the tail pipe under load.

Hillbilly66

And if you have a full exhaust.

When I got mine it was straight pipe, and came out the truck right behind the cab. It wasn't really the loudness it was the fact that it resonated in the cab, you could not have a conversation in the truck with out yelling.

BILTIT

Arent they that loud even when stock exhaust?

I dont even hear my exhaust, all engine noise really. The he351cw turbo does quiet things down though aswell.

mknittle

Things sure have changed since I was a kid.

aicomp

I hear that.