Do exhaust resonators rob horsepower??

[KATOOM]

I've been toying with the idea of getting an FTE resonator for awhile...
Watched this YouTube video and now I'm rethinking that decision. What say you guys?

 

[promisedland]

I had the same question, I have the 30" FTE res.
My guess is at 400hp I couldn't be loosing much, not 120!

 

[Jihn]

That's the cheapest engine brake I have ever seen, Internet experts know everything, how come when you enlarge your exhaust system you only get modest gains, oh I'm sorry this is the internet.

Jihn

 

[Regcabguy]

Drone's not worth it. I have a Shuttleworth HD diesel muffler out of Canada. Zero drone with a pretty acceptable noise level. In pursuit of something a bit quieter,I asked a local muffler/radiator shop that's been in biz for 50+ years here if there was anything else out there. He replied nope other than the stocker and that it would impact performance big time.
I helped another friend install a Magnaflow turbo back system. Good quality and fit but the drone drove him nuts and he's deaf in one ear. We reinstalled the stock system which includes the factory cat and he got a quieter muffler.

 

[promisedland]

Fire Punk knows their stuff, they are pros
Donaldson muffs are well spoken of, this might be a better bet KATOOM.
AH64ID likes them, They do flow tests on there mufflers.

 

[AEdelheit]

I call BS, I went from a large Donaldson 5" muffler that was on it when I bought the truck down to a cat back 4" with FTE resonator and did not notice any performance loss, I would think there would be pistons melting from the back pressure anything that creates a 120 hp loss due to exh restrictions.

 

[Brian Neal]

my only upgrade to the Cummins is the 4" MBRP exhaust, 30" FTE resonator and Flowmaster Hushpower muffler, been running this setup for almost 3 years...this eliminated the highway drone, reduced cabin noise by 3 dB, still has plenty of power for my needs, exhaust note is still distinctly Cummins but much more civilized. I can drive this truck all day now and not have my ears ringing like it did before the upgrade. I'm not interested in running this ol' buggy on a dyno cuz I need this truck to have practical utility, not interested in the macho rollin' coal horse-pookey...if there is any power loss, I would surmise that it would be a percentage of power output, not a straight number...

 

[Bob4x4]

Never did any before and after Dyno testing for a resonator but I did before and after a cat on a 12 valve at the 400hp level.The cat only took about 4hp.Draw your own conclusion.

 

[Regcabguy]

my only upgrade to the Cummins is the 4" MBRP exhaust, 30" FTE resonator and Flowmaster Hushpower muffler, been running this setup for almost 3 years...this eliminated the highway drone, reduced cabin noise by 3 dB, still has plenty of power for my needs, exhaust note is still distinctly Cummins but much more civilized. I can drive this truck all day now and not have my ears ringing like it did before the upgrade. I'm not interested in running this ol' buggy on a dyno cuz I need this truck to have practical utility, not interested in the macho rollin' coal horse-pookey...if there is any power loss, I would surmise that it would be a percentage of power output, not a straight number...

Most of the noise from my 24v came from under the hood even with the stock exhaust.

 

[savage54]

I heard for the drone , it all depends where you mount the resonator. Has any body played with the resonator location ?

 

[savage54]

When it comes to the drone from the exhaust, I heard it depends where you mount the resonator. I have a 97 with a 5.9 and MPRP 4inch turbo back with a MBRP muffler, if you can call it a muffler.

 

[KATOOM]

When it comes to the drone from the exhaust, I heard it depends where you mount the resonator. I have a 97 with a 5.9 and MPRP 4inch turbo back with a MBRP muffler, if you can call it a muffler.

Yes, drone is a specific "tone" of sound waves bouncing around the exhaust which have to be interrupted at the right moment in their travels otherwise the cancellation is far less effective. Look up exhaust pipe resonator wave generator and you'll understand what I mean.
Actually, I'm kinda surprised no one has made a wave generator for these trucks. There's plenty of room and they are offer no restriction.

 

[promisedland]

Mount the resonator as far forward as possible. In the muffler location I have a lil drone. I'm the cat location no drone.

 

[Brian Neal]

Agreed, ya want to mount the resonator directly under the passenger seat...with the 4" MBRP setup, I mounted the resonator to the downpipe, followed by an 8" pipe before the muffler, and a 4" pipe before the over-axle pipe. I ran just the resonator for a few months before adding the muffler, and it reduced cabin noise by 1dB and eliminated the drone. After adding the muffler, I could make the hour-long commute to the office and not need to ask coworkers to repeat themselves in the morning. I could even take 4hr road trips, have phone convos on the way, and normal convos once reaching my destination, something I had not been able to do with the factory setup...the Cummins is still plenty loud under the hood, but the noise downstream of the turbo doesn't affect my hearing nearly as bad as it had done for years

 

[Regcabguy]

How about a quieter muffler and not deal with a resonator?

 

[KATOOM]

I guess I just dont understand why some people say their 2nd gen's are so loud that you cant have a conversation with passengers. I have an aFe intake, no silencer ring, and a 4" exhaust with no muffler and my truck is still plenty quiet enough in the cab that listening to the radio and talking with passengers is just like being in any other vehicle. Yes, the engine is clacky and the loudest part of the 2nd gen's, but inside the cab of my truck is no where near as loud as I hear some people describe.

 

[Brian Neal]

To quantify the sound levels, I used an app I downloaded to my phone to measure sound levels in dBs, its accuracy is in the ballpark for comparative purposes. At 75mph, with the Cummins turning 2100 rpm, inside the QuadCab registers 77 dB. Dad's 2016 Ram 1500 Hemi comes in at 68 dB. Mom's 2015 Journey V6 registers 65 dB. My neighbor's 2015 Ram 1500 EcoDiesel rattles to 70 dB. Dad's New Holland TD60D in road gear has a cab that allows 80 dB in...the John Deere 5045 open station in road gear roars in at 82 dB.

Another property of the sound in the cab is the pitch. The factory exhaust has a drone that made my ears ring so that I could not hear certain voices but surrounding noises registered loud and clear. I could be on the phone with ppl and could only hear the engine...it was a real problem with lighter female voices, and some ladies ya just don't F with...

So cabin noise can be subjective if ya have hearing issues...my goal was to civilize my cab so I would have less miscommunication issues with my contacts, and I have partially succeeded...but some folks I ain't never gonna make happy

 

[Charlie Lawhon]

I actually had one of those way back in 97 and you'd think with that auger screw it would not be restrictive. For someone making a real deal 300-400 hp on the ground on the dyno it probably wouldn't cost you that much even though it does have some back pressure at that flow rate.

That said in the video they are talking about 700's and 800's on the dyno. Realistically I know all kind of people believe they are up over 400 but they're probably not over 400 on the ground with a stock head and stock cam.

If you have a stock head and cam I wouldn't worry about it. Put it on and call it a day. Quiet power is much cooler than a loud obnoxious police magnet.

 

[KATOOM]

I posted a thread years ago where I tested my trucks noise levels with a db meter. I measured in front of the truck hood closed, standing by the exhaust pipe, in the cab windows up/down, etc...

I cant seem to find the old thread but it was surprising to find that the db levels in the cab were only in the upper 60's - low 70's, about the same as our old minivan. And standing at the radiator was louder than standing at the exhaust tail pipe exit...
The 24 valve engines are some clacky noisemakers for sure, but my truck is what I'd consider to be comfortably quiet in the cab. Obviously I cant speak for others since it appears not everyone has the same opinion.

One thing I've shared before is there is a side kick plate down by your feet of the front seats. Behind that plastic cover is an opening which should have a bag of plastic stuffed in there as a sound deadening material. If its not there then the engine noise in the cab will likely be much louder.

 

[Regcabguy]

I guess I just dont understand why some people say their 2nd gen's are so loud that you cant have a conversation with passengers. I have an aFe intake, no silencer ring, and a 4" exhaust with no muffler and my truck is still plenty quiet enough in the cab that listening to the radio and talking with passengers is just like being in any other vehicle. Yes, the engine is clacky and the loudest part of the 2nd gen's, but inside the cab of my truck is no where near as loud as I hear some people describe.

If I still had my 2nd gen I'd install Dynamat. I'm one of those who had to crank up the radio in order to hear it and had to raise my voice in order to hear the passenger. I had a Jardine replacement turbo back exhaust on mine. Everytime I drove through the neighborhood people though UPS was coming. Those the 2nds are still the best styled Ram out there.