im lookin for new mufflers for my hiboy and i been checkin out all kinds of auto and truck forums online and the one word that keeps poppin up over and over again is DRONE DRONE DRONE but no one ever explains what it is. what the hell is drone

 

Drone is kinda like if you hum at a content level. Some say it's annoying, but it doesn't bother me.

 

Put some loose change in your ashtray, when cruising down the road at a steady rpm the coins start to "dance" that's exhaust drone (it kinda makes a "Hmmmmm" noise that 460FM mentioned above).

It's caused by the turbulence through the mufflers resonating through the frame and floor boards (i'm sure there's a more scientific explanation, but we'll just go with this one for now ).

Things you can do to alleviate it are...have a properly routed exhaust, install a crossover pipe (X or H), use rubber mounted hangers, use sound deadener and good floor matting..... or just turn up the radio.

 

Glass packs are usually the ones guilty of drone. Not always but a good majority of trucks that drone have some sort of glass packs. As said above, crossovers (x pipes help).

My fathers ranchero gt had magnaflows with no crossover and it droned like a ******* at idle. It rattled that little truck like nobody's business. I liken it to haveing a little single engine prop plane in the cab.

 

I used to have a 2500 ram with the cummins I had a bunch of work done to it . before I sold it I had tried a big single turbo instead of twins and w no muffler just the turbo and 5 in pipe all the way out the back, that thing when it reached 2000 rpm on highway felt like your ears were going to pop. it was weird .

I had rode in other trucks and they didn't have that same loud deep constant annoying sound. like a gang of 200 people humming as loud as they can .

in retrospect a muffler would have been a good option. but I enjoyed it then being obnoxious and blowing smoke on people, racing beating mustangs and Hondas, but have matured a little since then.

 

ahh i get it now i hear that sound mostly on ricers i just never knew it was called drone. i was leaning towards flowmasters cuz everyone says they are best but everything i read on em that drone word comes up. i was lookin at glass packs to anyone ever use cherry bombs or purple hornies? seems like every new truck around here has that flowmaster sound which is kinda boring. i want something more tough sounding but not crazy loud like strait pipes.

 

Ever have a woman go on and on and on and on about nothing you care about? That's drone. J/K

I've always associated it with a metallic humming noise that comes on at certain RPM's or speeds. Ever seen a metal tuning fork? Hit them together and they make that vibrating humming sound. The vibrations in the metal forks are caused by specific frequency. Same thing the specific frequency of the exhaust note at certain pitches will cause the metal to make that sound.

My motorcycle does the same thing at certain speeds.

 

To sum it up, it's called "resonance" or the first harmonic.

 

If they're louvered core i'd shy away, if they're perforated core go for it.

 

the sound of a short fat glasspack can not be beat, IMO. the thrush welded do sound pretty good too. i've got those on my chebbie plow truck, there is some drone at idle, but that's it.

the dent wears a single short fat glasspack, again, some drone at idle, but nothing at speed.

as HIHO said, look for a perforated core vs a louvered core. Every thrush i've looked at is perforated FWIW. they may make a louvered core, but i've never run across one.

shorter = louder
longer = quieter.

 

how do I tell the difference between the two??
happy dads day to all you dads out there

 

If you look down the inside of a glasspack, and you see little fins sticking up towards the inside of the pipe, it's louvered. If there are just a bunch of holes like perforated pipe, its a perforated core

Louvered


Perforated


It's true that packs are often the culprit of droning. Mine was terrible when the muffler was right under the passenger floor and dumped right there. After I moved the muffler rearward about a foot and put a 45 degree turndown, no issues.


-Jameson

 

^ ditto

Those pics look familiar

Go perforated core only.

 

Found em' on Google

x2 with perforated. Louvered tends to blow out fiberglass, and they are directional


-Jameson

 

As did I

Someone asked this very question a few months ago......nobody uses "search" anymore.