Need to kill cabin drone

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Jan 31, 2016 | 10:17 PM

#16

Tugly

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Joined: Jan 2011

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From: Puget Sound

Quote:

Originally Posted by ajbrown208

The new pipe exits in the same place as the old one did. So do y'all think the drone comes from portions of the pipe, out the back, or both? Tugly, I would assume you think from the pipe itself since you wrap your exhaust pipe....

Yep, it's the exhaust hardware. Blowing across a beer bottle makes a very specific tone, depending on how much beer is in the bottle. The volume is affected by how you blow across it. Blowing too hard or too light makes it quieter, then there's that just-right air flow that makes it loud. Likewise, the exhaust configuration makes the tone (resonance), and the load/RPM of the engine effects the sound level. For my truck, the sweet spot seems to be near 1500 RPM with some good boost going on (climbing a hill).

Wrapping the pipe isn't just a matter of blocking the noise like padding the cab - it's more like putting your hand on a tuning fork. The contact of the soft tissue prevents the vibration from being made in the first place. Couple that with the insulating qualities of the wrap, and the exhaust gets even quieter - plus less heat under the truck.

Jan 31, 2016 | 10:29 PM

#17

Jaime74656

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Joined: Apr 2011

Posts: 4,744

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From: Earth

Quote:

Originally Posted by Tugly

My post was assumeing that were looking to lessen the noise thats being heard from inside the cab at any (all ranges), hence the dynamat comment, now if we are talking the vibrations from an exhaust, yes I agree the wrap would be best, all this wrap stuff, dynamatting and any thing additional really is a cumulitive effect really, but I am looking at it as a whole picture type deal, if I were going to try and quiet things down, I would hit the wrapping, then also new exhaust that opens more free flowing but with mufflers (or resonators or both) along with the dynamat for keeping the out side noises out of the cab and making it quiet like most modern day cars are

Feb 1, 2016 | 02:17 AM

#18

Tugly

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Joined: Jan 2011

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From: Puget Sound

I just went after the drone because of the thread title, but yes... many of these trucks can be much quieter. I know this because I have the Lariat trim, which includes a lot of sound-deadening in the cab and engine bay - and it works on everything but drone. Back when I had the resonator to limit drone, the only whistle I had was through the S&B intake, but not the exhaust. Video 1 demonstrates the drone - but only if you are viewing this on a device with a big sound system. Video 2 has no drone, and you can hear the bass of the music through that same big sound system. The engine? Fuggetaboutit... you won't hear that through the Lariat trim and the tuning:

Feb 1, 2016 | 07:20 AM

#19

Dan V

Lead Driver

Joined: Jun 2013

Posts: 5,647

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From: north of Minneapolis, MN

Quote:

Originally Posted by Absolute

I have the MBRP but it droned too. I put the resonator on and it was much better, but as tugly said, no whistle. So I was told by MBRP to turn the resonator backwards. Now it whistles and the drone is much less. THey said it flows better backwards too, but doesn't muffle as much. SO pick your way, but the resonator is the fix, and sound proofing. A muffler will kill any benefit you got out of the new system. That's why they come with a resonator instead. Another solution I've heard is to splurge for the "Y" pipe set up and split it into two. Does nothing for performance, and cost a bit, but it is the best solution if you want it quiet. I've also notice if you point the tip to the back it lessons the drone. I think when it comes out the side it resonates threw the body.

Who's resonator?

And which direction did you install the MBRP muffler? ie: which direction are the louvers pointed? to the front, or to the back?

Feb 1, 2016 | 07:58 AM

#20

Tugly

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Joined: Jan 2011

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From: Puget Sound

When doing my homework, I looked at the FTE (good name) resonator... but the reviews showed it to be too restrictive. The Aero and the Diamond eye have the same design as each other, but very different from the FTE. I thought I wanted my Diamond Eye louvers pointing upstream.

I was wrong. Not only did this kill the drone, it also killed the whistle out the pipe - and I could hear the resonator "hum" through the truck. In other words, I traded a deep drone for a hum - but most people would never pick that out of all the other noises of... say... an XLT trim with a noisy tune, intake, and exhaust.

Since I have focused so much on noise abatement, I hear a lot of stuff that others could never pick out in their trucks. A good example is I can hear those injector solenoids clicking along - making a noise akin to a sewing machine.