So I been running 5" with a muffler and its sounding old. Back a few years ago I heard people talking about running Catalytic Converters that had a good sound to them. I just find it hard to put a cat on my truck. lol  Anybody running them or is it bunk?

No cat. 4" since 09 and no complaints. 5" tip. Banks SS.

4 inch exhaust with muffler. Still fairly loud in the cab with drone. Mostly climbing grades. My 3 inch was much quieter. As for EGT I've had no change really from 3 to 4. More change with the Quadzilla for EGT.

The 5" is not bad in cab but I was pulling farm tractor and a friend said good lord that thing was loud. I know its got to be loud, its over the axle and angled to the side some. The muffler is straight through so it cant muffle much at all. Is a resonator straight through?

I run a 5" Farm Boy Performance straight pipe exhaust.  It is not bad under low boost conditions but getting up around 20 psi & above it lets you know its there.  

Just now, LiveOak said:

I run a 5" Farm Boy Performance straight pipe exhaust.  It is not bad under low boost conditions but getting up around 20 psi & above it lets you know its there.  

 

Even my 4-inch muffled Diamond Eye drones really good by 15 PSI of boost. By 40 PSI she is screaming out that 5-inch tip. Loud!

I have a stainless 5" stainless steel muffled with no cat and it is quiet at highway speeds and any other speeds.  All I can hear is whistles from the turbos and some mechanical sounds from under the hood...absolutely no droning.  Got it from DAP. 

6 hours ago, jlwelding said:

Is a resonator straight through?

The FTE resonator is not flo thru. They have some sort spiral baffling in them. It is explained their site quite well.

4” is plenty for 500-600 rwhp. A 5” just causes more drone at lower power levels. 

 

My 05 had a 4” flo-pro with a 51” Donaldson muffler. Zero, and I really mean zero, drone. That was from idle thru WOT at 400 rwhp, even up to 23K GCW. Throaty but not abnoxious, and never at a volume that disrupted anything in the cab. 

 

Most of the aftermarket diesel mufflers don’t have the attenuation or flow to match the needs  of a mild-moderate 5.9.  If you look at the Donaldson catalog you will realize how big a muffler needs to be to meet the flow and have proper attenuation... then you’ll realize most the popular diesel mufflers are anemic and just don’t cut the sound properly. 

12 hours ago, Mopar1973Man said:

 

Even my 4-inch muffled Diamond Eye drones really good by 15 PSI of boost. By 40 PSI she is screaming out that 5-inch tip. Loud!

 

 

Screaming and drone are two very different things. So does it drone or scream? 

Both... Any grade makes it drone right at 60 to 65 MPH. Now stand on the throttle passing someone it screams. Muffler really only keeps it quiet in the city more so and flat cruise state.

I am leaning towards the resonator.

FTE resonator eliminated drone on my 5". Still sounds good

On 3/24/2019 at 2:52 PM, Bullet said:

I have a stainless 5" stainless steel muffled with no cat and it is quiet at highway speeds and any other speeds.  All I can hear is whistles from the turbos and some mechanical sounds from under the hood...absolutely no droning.  Got it from DAP. 

It's because you have twins,  I believe that is why less drone

I have a 5" Diamond Eye system on mine. When working it hard it roars to the point I can't hear the wife in the shotgun seat. You'll have to decide for yourself whether that's a good or bad thing.

2 hours ago, Dieselfuture said:

It's because you have twins,  I believe that is why less drone

That might be the case but if it is I do not understand the science behind why that would make a difference.  I thought it might be because my tailpiece sticks out a little further than my last one did and my last one droned a bit.  This one is a Diamond Eye stainless and my last one was aluminized...both with mufflers and both 5".

11 hours ago, Bullet said:

That might be the case but if it is I do not understand the science behind why that would make a difference.  I thought it might be because my tailpiece sticks out a little further than my last one did and my last one droned a bit.  This one is a Diamond Eye stainless and my last one was aluminized...both with mufflers and both 5".

 

Each turbo dissipates the noise, and straight piped twin turbo truck just isn't nearly as loud as a single turbo truck. 

3 hours ago, AH64ID said:

 

Each turbo dissipates the noise, and straight piped twin turbo truck just isn't nearly as loud as a single turbo truck. 

 

17 hours ago, Dieselfuture said:

It's because you have twins,  I believe that is why less drone

You know you guys are right on the money.  I made the exhaust switch at the exact same time I installed the twins and noticed how much quieter the exhaust was while idling.  At the time I just thought my new exhaust is much better than my old one...never once thinking about the effect of the extra turbo.  But now I can see how that would make the difference. 

The best muffler and resonator I've found is a s475. It's got a nice growl to it, and plenty of turbine noises.  

 

But, when I was still single turbo, I was able to get away with just a muffler.  Either I don't hear the drone or it doesn't bother me. 

2 hours ago, trreed said:

The best muffler and resonator I've found is a s475. It's got a nice growl to it, and plenty of turbine noises.

Lol...I concur! 

Getting a 4-5" fte 28 muffler today. Currently running a 5" aeroturbine. Its horribly loud.

 

I'll add a muffler behind the fte if it doesnt quite it.

 

Shooting to put fte ahead of tranny exhaust hanger. Right where down pipe goes horizontal 

 

 

This is a link with several pictures to when I had the Farm Boy Performance 5" straight pipe exhaust system installed about 10 years ago.  It is still in good condition and doing its job. Wow!  10 years already!  Where does the time go???

 

https://tractorfarmandfamily.com/topic/555-5-inch-turbo-back-exhaust-install-on-my-2002-dodge-ram-cummins-diesel/